Depression is one of the most prevailing medical disorders. Depression has been recognized as a distinct pathological entity from early Egyptian times (Reus, 2000).
Depression is the most common psychiatric disorders. Each year, more than 100 million people worldwide develop clinical depression (Bjornlund, 2010). During a lifetime, it is estimated that between 8% and 20% of the general population will experience at least one clinically significant episode of depression (Kessler et al., 1994).
Major depression causes the fourth-highest burden of disease among all medical diseases. It is expected to rise to second place, preceded only by cardiovascular disease by 2020 (Thompson, 2007).
Depressive disorder has significant potential morbidity and mortality. Suicide is the second leading cause of death in persons aged 20-35 years. Depressive disorder is a major factor in around 50% of these deaths (Semple et al., 2005).
A suicide attempt among patients with major depressive disorder is associated with the presence and severity of depressive symptoms. Lack of partner, previous suicide attempts and time spent in depression are risk factors of suicide attempts. Reducing the time of depression is a likely preventive measure of suicide (Sokero et al., 2005).
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Depression is a medically significant condition that needs to be diagnosed and properly treated. It is a severe disorder, tend to recur, and it costs the individual and society (Stefanis & Stefanis, 2002).
Epidemiology of Depressive Disorders
Prevalence and Incidence
Studies show substantial variability in the lifetime rates of depression. Lifetime rates are ranging from under 5 percent to 30 percent, but it is widely accepted that the lifetime prevalence is between 10 percent and 20 percent. The 6-month prevalence rate is considered to be between 2 percent and 5 percent based on surveys in several countries (Young et al., 2010).
A cross- sectional WHO world health survey carried out in 60 countries covering all regions of the world showed a 1-year prevalence of depressive episode of 3.2 percent, with a 95 percent confidence interval of 3.0 percent to 3.5 percent (Moussavi et al., 2007). The life time prevalence of depression for adults varied from 3 percent in Japan to 16.9 percent in the US, with most countries in the range between 8 percent and 12 percent (Andrade et al., 2003).
The prevalence of major depressive disorder is estimated to be about 2 percent in children (Birmaher et al., 1996). Estimates of the point prevalence of MDD in adolescence is range from 0.4 percent to 8.3 percent. Lifetime prevalence rates across adolescence range is from 15 percent to 20 percent (Roberts & Bishop, 2005).
In Dubai the prevalence of depressive disorders were 13.7% among women mostly neurotic depression (Ghubash et al., 1992).
About 12-20% of persons experiencing an acute episode develop a chronic depressive syndrome, and up to 15% of patients who have depression for more than one month commit suicide (Reus, 2000).
There is now substantial evidence that the genetic factors are of major importance as risk factors for vulnerability to major depression. Traditional estimates have put the heritability about 40 % (Joyce, 2003). Genetic influences are most marked in patients with more severe forms of depressive
disorder and 'biological' symptoms. The morbid risk in first-degree relatives is increased in all studies. This elevation is independent of the effects of environment or upbringing. In fewer severe forms of depression, genetic factors are fewer significant and environmental factors relatively more important (Souery et al., 1997).
Major depressive disorder is the twofold greater prevalence in women than in men independent of country or culture. The reasons for the difference are hypothesized to involve hormonal differences, the effects of childbirth, and differing on psychosocial stressors for women and for men (Sadock & Sadock, 2007).
Major depressive disorder occurs in all cultures and affects all age groups. Depression is common in Childhood and late adult. The mean age of onset is generally in the 30s (Dunner, 2008).
Early-onset depression is associated with a higher female to a male ratio than late-onset depression. The incidence of major depressive disorder in old age is lower in both sexes. However, first incidence and prevalence of minor depressive disorder shows the opposite trend (Rihmer & Angst, 2009).
In younger people, mild depression tends to affect anxious or dependent personalities with poor tolerance of stress. Severe depressive illness in middle age tends to affect hard-working, conventional people with high standards and obsessional traits. Obsessional personalities can find it, particularly difficult to adapt to stress or life changes, as in work or relationships, and this can 'come out' as depression (Gill, 2007).
Always on Time
Marked to Standard
Early theorizing suggested that the loss of a parent in childhood increased the later risk for major depression. However, many studies have examined this issue; they have inconsistently found it to be a risk factor for
adult depression (Tennant, 1988). Childhood sexual abuse has been established as a risk factor for adult major depression (Joyce, 2003).
Rates of depressive illness is lower in the married man than in the single, widowed, or divorced. The protective effects of marriage are less marked in women. Young married women with children have high rates of depression; single women have low rates (Gill, 2007). However, those in a poor marriage with deficient intimacy are at increased risk of depression (Weissman, 1987).
Social classes and occupation
People of low socio-economic status (i.e. low levels of income, employment, and education) are at higher risk of depression (Semple et al., 2005).
While job satisfaction can enhance mental well-being, the workplace can also be a source of stress and depression. However, the consequences of unemployment probably have far changed on mental health. The economic hardship to the unemployed and their families with depression due to long-term unemployment hindering job seeking and re-employment chances, exacerbated by loss of confidence and perceived loss of skills (Strandh, 2001).
Depression is more common in urban than a rural district (Gill, 2007).
Having a chronic or severe physical illness is associated with an increased risk for depression. This suggests that the stress associated with a serious or chronic physical illness may act by bringing out an individual's lifetime vulnerability to depression (Joyce, 2003).
Etiology of Depressive Disorders
The etiology of major depressive disorder is unknown (Dunner, 2008). Multiple etiologic factors genetic, biochemical, psychodynamics, and socio-environmental may interact in complex ways to cause major depressive disorder (Loosen & Shelton, 2011).
GENETIC MODELS OF DEPRESSION
There is evidence to suggest a genetic basis for the major depression disorder. Occurrences of major depressive episodes are clearly cluster in families. This degree of increased risk is about three to five times that of the normal population.
Twin and adoption study is consistent with a genetic contribution to major depressive disorders. However, studies suggest that other factors also are important (Schiffer, 2008). Actually, it is the tendency to become depressed in response to life events that are inherited (Hirschfield & Weissman, 2002). Moreover, family and twin studies show a clear genetic component of life events themselves (Kendler & Karkowski, 1997).
ENDOCRINE MODELS OF DEPRESSION
Neuroendocrine abnormalities that reflect the neurovegetative signs and symptoms of depression include: first, increased cortisol and corticotrophin-releasing hormone (CRH) secretion, second, an increase in adrenal size, third, a decreased inhibitory response of glucocorticoids to dexamethasone, and fourth, a blunted response of thyroid-stimulating hormone (TSH) level to infusion of thyroid-releasing hormone (TRH). Antidepressant treatment leads to normalization of these pituitary-adrenal abnormalities (Reus, 2008).
Thyroid hormone may potentiate both the speed and the efficacy of antidepressant medication (Altshuler et al., 2001). Furthermore, there also evidence that patient resistant to other treatments may respond to addition of thyroid hormone (Joffe & Marriott, 2000).
NEUROCHEMICAL MODELS OF DEPRESSION
The most famous hypotheses generated to account for the actual mechanism of the mood disorder focus on regulatory disturbances in the monoamine neurotransmitter systems, particularly that involving norepinephrine and serotonin (5-hydroxytryptamine). It has also been hypothesized that depression is associated with an alteration in the acetylcholine-adrenergic balance and characterized by a relative cholinergic dominance. In addition, there are suggestions that dopamine is functionally decreased in some cases of major depression.
Original reports suggesting that patients with endogenous depression experienced either decreased noradrenergic or serotonergic activity now appear to be overly simplistic. All the monoamine neurotransmitter systems are interrelated and subject to compensatory adaptation to perturbation over time (Reus, 2000).
CELLULAR MODELS OF DEPRESSION
Most current hypotheses of neurotransmitter function in altered mood states have focused on changes in receptor sensitivity and second messenger
systems. With a few exceptions long-term antidepressant treatment is associated with reduced postsynaptic Î²-adrenergic receptor sensitivity and enhanced postsynaptic serotonergic and cyclic adenosine monophosphate activity (Reus, 2000).
A number of intracellular changes which involve alterations in cellular second messenger systems and ion channels are postulated to occur in depression. Intracellular changes may involve changes in guanine triphosphate binding proteins, G-proteins on the receptor, cyclic adenosine monophosphate (cAMP) regulation, reduced protein kinase activity and brain derived neurotrophic factor (BDNF). Antidepressants as well as ECT increase BDNF and BDNF have been found to increase functioning of serotonin (Kay & Tasman, 2006).
NEUROIMAGING MODELS OF DEPRESSION
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Recent rapid advances in neuroimaging methodology have attempted to relate the phenomenological abnormalities seen in depression to
changes in brain structure and function (Fu et al., 2003). There is increasing evidence that depression may be associated with structural brain pathology. Magnetic resonance imaging (MRI) has revealed decreased volume in cortical regions, particularly the frontal cortex, but also in subcortical structures, such as the hippocampus, amygdala, caudate, and putamen (Sheline & Minyun, 2002).
The most widely replicated Positron emission tomography (PET) scanning (PET) finding in depression is decreased anterior brain metabolism, which is generally more pronounced on the left side. In addition, increased glucose metabolism has been observed in several limbic regions (Thase, 2009).
Neuroimaging has also helped in the further investigation of the neurochemical deficits in depression. The largest study to date using PET found a marked global reduction in brain 5-HT2 receptor binding (22-27%) in various regions (Sheline & Minyun, 2002).
There is an increasing literature using neuroimaging to understand suicidality, particularly in depression. Mann (2005) cites several imaging studies suggesting decreased serotonin function in suicidal individuals and decreased activity in associated areas of the dorsal system involved in emotion regulation, such as the anterior cingulate. A number of regions more speciï¬c to suicidality are also highlighted, particularly those that seem to be involved in impulsivity and aggression, such as the right lateral temporal cortex, right frontopolar cortex, and right ventrolateral prefrontal cortex (Goethals et al., 2005). This literature has as well found structural abnormalities in relevant regions of the dorsal system, particularly the orbitofrontal cortex, which has speciï¬cally been linked to potential decision making deï¬cits that could lead to suicidality. Thus, such data potentially suggest clinically important subtype differentiation in brain function for this symptom (Ingram, 2009).
Stressful life events more often precede first, rather than subsequent, episodes of mood disorders. Some clinicians believe that life events play the primary or principal role in depression; others suggest that life events have only a limited role in the onset and timing of depression. Data indicate that the life event sometimes associated with development of depression is losing a parent before age 11. The loss of a spouse is the environmental stressor most often
associated with the onset of an episode of depression.
Another risk factor is unemployment; persons out of work are three times more likely to report symptoms of an episode of major depression than those who are employed (Sadock & Sadock, 2007).
PSYCHODYNAMIC THEORIES OF DEPRESSION
Psychoanalytic theory as postulated by both Freud and Abraham emphasized the connection between mourning and melancholia. The melancholic patient experiences a loss of self esteem with associated helplessness, prominent guilt and self deprecation. According to the theory, these symptoms result from internally directed anger or aggression turned against the self, leading to a depressive experience (Kay & Tasman, 2006).
Melanie Klein understood depression as involving the expression of aggression toward loved ones. Edward Bibring regarded depression as a phenomenon that sets in when a person becomes aware of the discrepancy between extraordinarily high ideals and the inability to meet those goals. Edith Jacobson saw the state of depression as similar to a powerless, helpless child victimized by a tormenting parent.
Silvano Arieti observed that many depressed people have lived their lives for someone else (a principle, an ideal, or an institution, as well as an individual) rather than for themselves. Heinz Kohut's conceptualization of depression, derived from his self-psychological theory, rests on the assumption that the developing self has specific needs that must be met by parents to give the child a positive sense of self-esteem and self-cohesion. When others do not meet these needs, there is a massive loss of self-esteem that presents as depression. John Bowlby believed that damaged early attachments and traumatic separation in childhood predispose to depression. Adult losses are said to revive the traumatic childhood loss and so precipitate adult depressive episodes (Sadock & Sadock, 2007).
Interpersonal Theory (IPT)
Interpersonal theory focuses on difficulties in current interpersonal functioning. In IPT, depression is held to relate to one or more of four functional areas: grief, interpersonal role disputes, role transitions, and interpersonal deficits.
In IPT, the reciprocal relationship between one's mood and interpersonal events is investigated. Stressful life events may overwhelm coping ability and produce a depressed mood, which then contributes to ongoing interpersonal difficulties. Once this relationship is identified, modifying it becomes the focus of treatment (Grunze et al., 2008).
THE COGNITIVE MODEL
Cognitive theories of depression hypothesize that particular negative ways of thinking increase individuals' probability of developing and maintaining depression when they experience stressful life events. According to these theories, individuals that possess specific maladaptive cognitive patterns are vulnerable to depression because they tend to develop negative information processing about themselves and their experiences (Sanderson & McGinn, 2001).
Martin Seligman developed the theory of learned helplessness as he was searching for an animal model of depression. In this formulation, individuals in stressful situations in which they are unable to prevent or alter an aversive stimulus (i.e., physical or psychic pain) withdraw and make no further attempts to escape even when opportunities to improve the situation become available (Reus, 2000).
Clinical Features of Depressive Disorders
Depressed mood is the most characteristic symptom, occurring in over 90% of patients. The patient usually describes himself or herself as feeling sad, low, empty, hopeless, gloomy, or down in the dumps. The physician often observes changes in the patient's posture, speech, faces, dress, and grooming consistent with the patient's self-report. A small percentage of patients does not report a depressed mood, usually referred to as masked depression. Similarly, some children and adolescents do not exhibit a sad demeanor, presenting instead as irritable or odd (Loose & Shelton, 2008).
Anhedonia manifests with a lack of interest in formerly pleasurable activities; sports and hobbies, etc. no longer arouse patients, and if they force themselves to partake, they take no pleasure in such activities. Libido is routinely lost and there is no pleasure in sexual activity (Moore, 2008).
Depressed individuals frequently report cognitive changes that include impaired attention, concentration, and decision making (Woo & Keatinge, 2008).
Sleep may be increased or decreased. Insomnia is one of the major manifestations of depressive illness and is characterized more by multiple awakenings, especially in the early hours of the morning than by difficulty falling asleep. Young depressive patients, especially those with bipolar tendencies, typically complain of hypersomnia, sleeping as long as 12 to 15 hours a day. Obviously, such patients will have difficulty getting up in the morning.
Although decreased sexual desire occurs in both men and women, women are more likely to complain of infrequent menses or cessation of menses. Decrease or loss of libido in men often results in erectile failure (Dunner, 2008).
Appetite can be decreased or increased with or without weight loss or gain; the most typical pattern is a decrease in appetite with weight loss (Faravelli et al., 2005).
Psychomotor disturbances include, on the one hand, agitation and on the other, retardation. Agitation, usually accompanied by anxiety, irritability and restlessness, is a common symptom of depression. In contrast, retardation, manifested as slowing of bodily movements, mask-like facial expression, lengthening of reaction time to stimuli, increased speech paucity. The extreme form of retardation is an inability to move or to be mentally and emotionally activated (stupor) (Stefanis & Stefanis, 2002).
The attitude and outlook of these patients may become profoundly negative and pessimistic. They have no hope for themselves or for the future. Self-esteem sinks and the workings of conscience become prominent. Patients see themselves as worthless, as having never done anything of value. Rather they see their sins multiply before them (Moore & Jefferson, 2004).
Suicidal ideation is almost always present. At times this may be merely passive and patients may wish aloud that they might die of some disease or accident. Conversely, it may be active, and patients may consider hanging or shooting themselves, jumping from bridges, or overdosing on their
medications. Often the risk of suicide greatest as patients begin to recover. Still seeing themselves worthless and hopeless sinners, these patients, now with some relief from fatigue, may find themselves with enough energy to carry out their suicidal plans.
The overall suicide rate in major depressive disorder is about 4 percent; among those with depressive episodes severe enough to prompt hospitalization, however, the rate rises to about 9 percent (Moore, 2008). Up to 15 percent of untreated or unsatisfactorily treated patients give up hope of ever recovering and kill themselves (Akiskal, 2009).
Proximal risk factors for suicide include agitation, current suicidal intent or plan, severe depression and/or anhedonia, instability (e.g., alcohol abuse or decline in health), recent loss, and availability of a lethal agent. Distal risk factors include a current suicidal intent with a plan, personal or family history of suicide, aggressive or impulsive behavioral pattern, poor response to treatment for depression, poor treatment alliance, a history of abuse or trauma, and/or substance or alcohol abuse (Hawton & Harriss, 2007).
Paranoid symptoms can occur among patients with major depression. There are usually exaggerated ideas of reference associated with notions of worthlessness. Characteristic delusions of patients with depression are those of a hypochondriacal or nihilistic type. Hallucinations may also occur in major depression. These commonly involve accusatory voices or visions of deceased relatives associated with feelings of guilt (North & Yutzy, 2010).
Adolescent-onset depression often takes on a more chronic course associated with dysthymic symptoms. In adolescence, MDD appears to be associated with greater fatigue, worthlessness and more prominent vegetative signs. The sequelae of depression in children and adolescents are sometimes characterized by disruption in school performance, social withdrawal, increased behavioral disruption and substance abuse (Kay & Tasman, 2006).
Among the elderly, agitation and hypochondriacal concerns are common, and indeed the patient may deny feeling depressed at all. Memory and concentration may be so impaired in demented elderly. In the past, this has been called a "pseudodementia," presumably to distinguish it from other kinds of dementia. However, a better, more recent term is "dementia syndrome of depression" (Moore & Jefferson, 2004).
Elderly people are more likely than younger adults to have a depressive illness that goes undetected and thus untreated, which may contribute to the high risk
of suicide among older patients. The suicide rate of this population is higher than for any other age group, and the attempts are serious: One out of four succeeds, compared with one out of two hundred for young adults (Bjornlund, 2010).
Diagnosis and Classification of Depressive Disorders
Depression conceives a variety of psychic and somatic syndromes, and the diagnosis is derived from diligent clinical observation (Grunze et al., 2008).
Depression as a term in popular use is mostly considered to be synonymous with low mood or grief. Depression mental (and medical) disorder, however, is different, and besides low mood, is characterized by a variety of additional symptoms (Grunze et al., 2008).
Depressive disorders are defined by clinically derived standard diagnostic criteria of emotional, behavioral, cognitive, and somatic symptoms, and associated with functional impairment. They are assessed through structured clinical interviews and observation. The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 2000) and International Classification of Diseases 10 (ICD-10; World Health Organization, 1992) use the same criteria to diagnose depressive disorders in children, adolescents, and adults (Roberts & Bishop, 2005).
The term affect usually refers to the outward and changeable manifestation of a person's emotional tone, whereas mood is a more enduring emotional orientation that colors the person's psychology (American Psychiatric Association, 1984).
Subtypes of Depressive Disorders:
Major Depressive Disorder (MDD)
According to DSM-IV-TR, a major depressive disorder occurs without a history of a manic, mixed, or hypomanic episode. A major depressive episode must last at least 2 weeks. Typically, a person with a diagnosis of a major depressive episode also experiences at least four symptoms from a list that includes changes in appetite and weight, changes in sleep and activity, lack of energy, feelings of guilt, problems thinking and making decisions, and recurring thoughts of death or suicide (Sadock & Sadock, 2007). Table 1.1.1 shows DSM-IV-TR criteria for major depressive episode.
Unipolar and Bipolar Depression
When a person develops an episode of mania they are conventionally identified as suffering from bipolar disorder. Patients with depressive episodes only are diagnosed as having unipolar depression (Baldwin & Birtwistle, 2002).
Individuals with melancholic depression experience a loss of pleasure in all or almost all activities or are nonreactive to usually pleasurable activities (American Psychiatric Association, 2000). In addition, according to the DSM-IV-TR, the individual must display three or more symptoms from a list of six, such as worsening depression in the morning, early morning awakening, significant weight loss or anorexia, and the perception that one's mood is qualitatively different from that experienced in other contexts. Melancholic depression is considered a severe form of affective illness (Woo & Keatinge, 2008).
Self-belittlement, an exaggerated sense of guilt, a feeling that life is pointless and that one has failed in everything are very often accompanied by severe recurrent suicidal thoughts and thoughts about death. However, the risk of suicide usually first becomes prominent when the patient is in the process of
improvement and the psychomotor inhibition decreases while, at the same time, expectations about the capacity to cope with the psychosocial situation are still very negative (Wasserman, 2001).
Table 1.1.1 DSM-IV-TR criteria for major depressive episode
Five (or more) of the following symptoms have been present during the same 2-week period and represent a change from previous functioning; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure.
Note: Do not include symptoms that are clearly due to a general medical condition, or mood-incongruent delusions or hallucinations.
depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad or empty) or observation made by others (e.g., appears tearful). Note: In children and adolescents, can be irritable mood.
markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by either subjective account or observation made by others)
significant weight loss when not dieting or weight gain (e.g., a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day. Note: In children, consider failure to make expected weight gains.
insomnia or hypersomnia nearly every day
psychomotor agitation or retardation nearly every day (observable by others, not merely subjective feelings of restlessness or being slowed down)
fatigue or loss of energy nearly every day
feelings of worthlessness or excessive or inappropriate guilt (which may be delusional) nearly every day (not merely self-reproach or guilt about being sick)
diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective account or as observed by others)
recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide
The symptoms do not meet criteria for a mixed episode.
The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition (e.g., hypothyroidism).
The symptoms are not better accounted for by bereavement, i.e., after the loss of a loved one. The symptoms persist for longer than two months or are characterized by marked functional impairment, morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms, or psychomotor retardation.
Source. Reprinted from American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision. Washington, DC, American Psychiatric Association, 2000.
About 50% of major depressive episodes are unrecognized because depressed mood is less obvious than other symptoms of the disorder. Alexithymia, or inability to express emotions in words, can focus a patient's attention on physical symptoms of depression, such as insomnia, low energy,
and difficulty concentrating, without any awareness of feeling depressed. Common masked presentations of major depression include marital and family conflicts, absenteeism from work, poor school performance, social withdrawal, loss of a sense of humor, and lack of motivation (Joska & Stein, 2008).
Seasonal depression is a condition in which depressed mood accompanied by lethargy, excessive sleep, increased appetite, and irritability recurs each winter. It was believed to respond exclusively to light treatment. However, recent studies indicate it can be just as effectively managed with standard methods of treatment, such as medication (Gill, 2007).
The term psychotic depression (or delusional depression) refers to a major depressive episode accompanied by psychotic features (i.e., delusions and/or hallucinations). Most studies report that 16%-54% of depressed patients have psychotic symptoms. Delusions occur without hallucinations in one-half to two-thirds of the adults with psychotic depression, whereas hallucinations are unaccompanied by delusions in 3%-25% of patients. Half of all psychotically depressed patients experience more than one kind of delusion (Dubovsky & Thomas, 1992).
Dysthymia refers to symptoms of mild depression, which have persisted for at least two years. Symptoms fluctuate more than in major depression, and they are 'typical' including insomnia, lack of appetite, or poor concentration (Bech, 2003).
Double depression characterized by the development of MDD superimposed upon a mild, chronic dysthymic disorder (DD). Individuals with double depression often demonstrate poor interepisode recovery. Furthermore,
25% of the depressed individuals manifest double depression (First &Tasman, 2006).
Table 1.1.2 shows DSM-IV-TR criteria for dysthymic disorder.
Table 1.1.2 DSM-IV-TR diagnostic criteria for dysthymic disorder
Depressed mood for most of the day, for more days than not, as indicated either by subjective account or observation by others, for at least 2 years. Note: In children and adolescents, mood can be irritable and duration must be at least 1 year.
Presence, while depressed, of two (or more) of the following:
poor appetite or overeating
insomnia or hypersomnia
low energy or fatigue
poor concentration or difficulty making decisions
feelings of hopelessness
During the 2-year period (1 year for children or adolescents) of the disturbance, the person has never been without the symptoms in Criteria A and B for more than 2 months at a time.
No major depressive episode has been present during the first 2 years of the disturbance (1 year for children and adolescents); i.e., the disturbance is not better accounted for by chronic major depressive disorder, or major depressive disorder, in partial remission.
Note: There may have been a previous major depressive episode provided there was a full remission
(no significant signs or symptoms for 2 months) before development of the dysthymic disorder. In
addition, after the initial 2 years (1 year in children or adolescents) of dysthymic disorder, there may be
superimposed episodes of major depressive disorder, in which case both diagnoses may be given when
the criteria are met for a major depressive episode.
There has never been a manic episode, a mixed episode, or a hypomanic episode, and criteria have never been met for cyclothymic disorder.
The disturbance does not occur exclusively during the course of a chronic psychotic disorder, such as schizophrenia or delusional disorder.
The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition (e.g., hypothyroidism).
The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
The Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR).
Unipolar depression in elderly patients is often associated with cerebrovascular disease, especially on the left side of the brain. Depression that appears for the first time in the geriatric patient is more difficult to treat than depression that begins earlier in life because of the likelihood of associated neurological impairment (Dell & Stewart, 2000).
Postnatal Depressive Disorders
Most women (up to 80%) experience some mild let down of mood in the postpartum period. For some of these (10-15%), the symptoms are more severe and similar to those usually seen in serious depression. There is an increased emphasis on concerns related to the baby (obsessive thoughts about harming it or inability to care for it). When psychotic symptoms occur, there is frequently associated sleep deprivation, volatility of behavior, and manic-like symptoms (Eisendrath & Lichtmacher, 2011).
Assessment of Depressive Disorder
A careful general medical assessment to ascertain the presence of an etiologic general medical condition is required. The assessment will require general medical examination, including a physical examination and laboratory testing. Laboratory studies in the management of the individual with MDD includes a complete blood count with differential, electrolytes, chemical screening for renal and liver function, as well as thyroid function studies. More detailed evaluation will depend upon the nature of the clinical presentation. After the assessment for general medical conditions, one examines the individual for the presence of alcohol or drug dependence. Then the clinician is required to assess retrospectively the occurrence of prior episodes of mood disorder, either depression or mania. It is necessary to examine for other comorbid psychiatric disorders as well (Kay & Tasman, 2006).
To assess risk for suicide, one inquires about the presence of active suicidal
ideation in relation to the current episode of depression and a history of prior suicide attempts. The occurrence of significant life events such as separation, divorce and death of significant others may precipitate the episode. The presence of a recent suicide attempt may suggest the need for immediate hospitalization and treatment (Kay & Tasman, 2006).
Measuring the severity of depressive symptoms are probably the most frequent assessment goal in both clinical and research settings. Such measures generally include a listing of symptoms thought to be important characteristics of depression across behavior (e.g., sleep patterns), affect (e.g., sadness), cognition (e.g., thoughts of suicide), and motivation (e.g., loss of pleasure) and require a rating of the presence or severity of such symptoms (Nezu & Nezu, 2009).
Psychological testing such as the Rorschach Inkblot Test are sensitive to the degree of affective lability, intensity of suicidality, and impulse control in individuals with depression. Self-administered scales include the Beck Depression Inventory, the Zung Self-Rating Depression Scale, and the Inventory for Depressive Symptomatology (self-report). Clinician administered scales used for assessment of depressive symptoms include the Hamilton Rating Scale for Depression, the Montgomery Asberg Depression Rating Scale, and the Inventory for Depressive Symptomatology (clinician rated) (First &Tasman, 2006).
Differential Diagnosis of Depressive Disorders
A diagnosis of depression is made if the individual is significantly impaired by the depressive symptoms and if three exclusion criteria are met: (1) the illness is not due to the effects of a substance (e.g. drug of abuse or medication) or a general medical condition, (2) the illness is not part of a mixed episode, and (3) the symptoms are not better accounted for by bereavement (Loosen & Shelton, 2011).
Major depressive disorders are differentiated from the following conditions or disorders:
Depressed mood as an essential component of pathological depression has its equivalent in the emotional response of practically all normal individuals when faced with losses, rejections and the adversities and changes of life. In contrast with normal sadness, the depressed mood: (a) may not be associated with a really adverse event, and if losses are reported, they are grossly
exaggerated, anticipated or imagined; (b) is extremely painful, persistent and pervasive, resisting all attempts to change by encouragement or reasoning; (c) is commonly associated with worthlessness, low self-esteem, and sustained self-depreciation; (d) frequently worsens with time and impacts on interpersonal relations and daily functioning; (e) is associated with guilt feeling and death wishes; (f) involves, if severe enough, somatic-vegetative symptoms and delusional ideation; (g) is more frequently than in normal sadness associated with rhythm disturbances and hormonal dysregulation (Stefanis & Stefanis, 2002).
Many neurological and medical disorders and pharmacological agents can produce symptoms of depression. Most medical causes of depressive disorders can be detected with a comprehensive medical history, a complete physical and neurological examination, and routine blood and urine tests. The workup should include tests for thyroid and adrenal functions, because disorders of both endocrine systems can appear as depressive disorders. Cardiac drugs, antihypertensives, sedatives, hypnotics, antipsychotics, antiepileptics, antiparkinsonian drugs, analgesics, antibacterials, and antineoplastics are all commonly associated with depressive symptoms (Sadock & Sadock, 2007).
Other Psychiatric Disorders
Depressive episodes can be confused with normal grief reactions (bereavement) after the death of a loved one. Usually, grief reactions are
associated with symptoms of insomnia, poor appetite, and weight loss, and are not associated with decreased self-esteem or suicidal ideation. The duration of normal bereaved is culturally determined. The DSM-IV suggests that, if such symptoms of depression persist for more than two months after the loss. The diagnosis of MDD should be considered (Friedman, 2011).
Dysthymia is a depressive disorder that is chronic in nature and requires that an individual experience a depressed mood on more days than not for at least two years. Dysthymia generally is characterized by fewer and fewer severe symptoms. Symptoms such as decreased energy, suicidal ideation, concentration problems, and eating and sleeping disturbances are milder and not as prevalent compared with patients diagnosed with major depressive disorder (Klein et al., 1996).
The distinction between a depressive episode occurring as part of a major depression and a depressive episode occurring as part of a bipolar disorder is critical and at times very difficult. Certainly, with a history of mania, a diagnosis of major depression is definitely ruled out. The majority of patients with a bipolar disorder begin their illness with a depressive episode, and they may have more than one before the first manic episode occurs (Moore & Jefferson, 2004).
Atypical depression is characterized by prominent mood reactivity in which there is excessive responsiveness of mood to external events. At least two of the following associated features: increased appetite or weight gain, hypersomnia, leaden paralysis (a feeling of profound anergia or heavy feeling) and interpersonal hypersensitivity (rejection sensitivity) (Kay & Tasman, 2006).
The presence of a major depressive episode may occur from two weeks to 12 months after delivery. Depression is seen in 10-20% of women after childbirth. The postpartum onset episodes can present either with or without
psychosis. Postpartum psychotic episodes occur in 0.1-0.2% of deliveries. Depression in postpartum psychosis is associated with prominent guilt (First &Tasman, 2006).
Posttraumatic Stress Disorder
Posttraumatic stress disorder, Briquet's syndrome, and hypochondriasis may all be complicated by depressive symptoms. However, here the depressive symptoms occur within the context of the other symptoms of these illnesses (Moore & Jefferson, 2004)
Generalized Anxiety Disorder
Severe generalized anxiety disorder is distinguished from an agitated depressive episode by the relative absence of such symptoms as fatigue, loss of interest, guilt, and middle insomnia or early-morning awakening (Moore & Jefferson, 2004).
The presence of psychotic symptoms not restricted to periods of disturbed mood helps distinguish the schizoaffective disorders from major depressive disorder (Woo & Keatinge, 2008).
Adjustment disorders are behavioral or emotional disorders that occur in response to an identifiable stress or stressors. The emotional component can involve sadness, low self-esteem, suicidal behavior, hopelessness, helplessness, or other self-threatening behavior. Acute adjustment disorder occurs within three months of the stressor and does not last longer than six months. The pattern of recurrent maladaptive behavioral responses to stress may be life long, but the acute episode should resolve within six months (Saveanu et al., 2009).
Alcohol and Cocaine Withdrawal
Active alcoholism, alcohol withdrawal, and withdrawal from cocaine or stimulants are all typically complicated by depressive symptoms, which may be severe. Here, however, within 3 or 4 weeks of abstinence, symptoms begin to clear spontaneously (Moore & Jefferson, 2004).
Dementia Syndrome of Depression
Clinicians can usually differentiate the pseudodementia of major depressive disorder from the dementia of a disease, such as dementia of the Alzheimer's type, on clinical grounds. The cognitive symptoms in major depressive disorder has a sudden onset, and other symptoms of the disorder, such as a self-reproach, are also present. A diurnal variation in the cognitive problems, which is not seen in primary dementias, may occur. Depressed patients with cognitive difficulties often do not try to answer questions, whereas patients with dementia may confabulate (Sadock & Sadock, 2007).
Borderline Personality Disorder
Borderline personality disorder is characterized by unstable personal relationships, unstable self-image, and inappropriate behaviors. The disorder may include chronic feelings of emptiness, which may be misdiagnosed as depression, or lability of mood, which may be mistaken for mania or hypomania (Saveanu et al., 2009).
The most common comorbid disorders with depressive disorders are anxiety disorders and substance-abuse disorders. The second key area of comorbidity with major depression is with alcohol dependence. Another area of considerable comorbidity with major depression is the personality disorders (Joyce, 2003).
Course and Prognosis of Depressive Disorders
Depression can start at any time in life. Genetic factors play a more important role in early-onset depression. Late-onset depression is less likely to be associated with a family history and tends to be milder but more likely to become chronic than early-onset depression (Young et al., 2010).
Major depressive disorder (MDD) must be viewed as a serious medical illness. Although depression is treatable, the prognosis for an individual diagnosed with MDD involves important implications regarding morbidity, social functioning and mortality. Patients with MDD report health difficulties and actively use health services. Over a lifetime, the presence of one major depressive episode is associated with a 50% chance of a recurrent episode. A history of two episodes is associated with a 70 to 80% risk of a future episode. Three or more episodes are associated with extremely high rates of recurrence. Because the majority of cases of MDD recur, continuation treatment and ongoing education regarding warning signs of relapse or recurrence are essential in clinical care (Kay & Tasman, 2006).
Depressive episodes may remit completely, partially, or not at all. The patient's functioning usually returns to the premorbid level between episodes. However, 20-35% of patients show persistent residual symptoms and social or occupational impairment (Loosen & Shelton, 2011).
Positive prognostic indicators include an absence of psychotic symptoms, a short hospitalization or duration of depression, and good family functioning. Poor prognostic indicators include a comorbid psychiatric disorder, substance abuse, early age at onset, long duration of the index episode, and inpatient hospitalization (Loosen & Shelton, 2011).
About two-thirds of people who commit suicide suffer from depression. Angst et al. (2005) followed up 406 patients with a unipolar depression or bipolar disorder from 1963 to 2003. By 2003, they found that 11.1% of these patients had committed suicide. This underlines the prominent role of early diagnosis and treatment of depression for suicide prevention. The overall death
rate for patients with depression is higher than the general population with the cause of death usually due to suicide, drug and alcohol problems, accidents, cardiovascular disease, respiratory infections, and thyroid disorders (Semple et al., 2005).
Suicide events are most common immediately before treatment initiation and during the interval until treatment becomes effective; during these early phases, doctors should plan frequent follow-up visits and also consider a possible supporting role for family members and caregivers (Grunze et al., 2008).
Depression is a major mental health problem. It impairs psychosocial and occupational functioning and is associated with significant morbidity and mortality. Suicide may preoccupy the depressed patient's thinking and may reinforce feelings of helplessness, perpetuating self-reproach. The patient may formulate a definite plan for ending life. Depressed patients must be questioned about suicidal thoughts and plans, which allows them to describe their pain and may provide them with some relief. Depression is a mental disorder which, due to its severity, its tendency to recur and its high cost for the individual and for society, is a medically significant condition that needs to be diagnosed and properly treated.