Approximately five decades ago Aaron T. Beck and Albert Ellis described the concepts that are central to cognitive-behavioral therapy (CBT). Since its inception, more than 300 controlled trials supporting its efficacy have been conducted (Sudak, 2006). The vast amount of research conducted exploring the efficacy of cognitive therapy has made it the psychotherapeutic treatment with the most empirical support (Sudak, 2006). Although CBT was originally developed to treat depression, the efficacy of the treatment has led many researchers to adapt it from the original structure and developed ways to use CBT for other psychiatric disorders, including hypochondriasis, bulimia nervosa, panic disorders, social phobia, and generalized anxiety disorder (Sudak, 2006). Research investigating schizophrenia and bipolar disorder suggests that there are improved outcomes for patients when standard pharmacotherapy is used in conjunction with CBT (Sudak, 2006). Furthermore, CBT has been found to be effective as a treatment in obsessive-compulsive disorder, posttraumatic stress disorder, and simple phobia; however, when treating these disorders the focus tends to be on the behavioral aspect with an understanding that the patient is also experiencing cognitive disturbances (Sudak, 2006). Since CBT emphasizes testing therapeutic models contained within the rubric of CBT for accuracy, its efficacy in treating multiple psychological disorders continues to improve. The emphasis on testing has enabled CBT to rapidly grow as a therapeutic technique and expand cognitive therapists' understanding of what approaches work best for specific individuals.
Fundamentals of Cognitive-Behavioral Therapy
There are three fundamental propositions at the core of all CBTs according to Dobson (2010):
Cognitive activity affects behavior.
Cognitive activity may be monitored and altered.
Desired behavior change may be effected through cognitive change.
The first fundamental proposition of CBT listed above is essentially the cognitive mediational model first proposed by Mahoney (1974). The cognitive mediational model is used to reduce anxiety in individuals through modifying affect-eliciting cognitions (Dobson, 2010). The model assumes that emotional stimulation is mediated by cognition rather than environmental cues. Thus, it would be possible for an individual to reduce anxiety by modifying thoughts that typically elicit and reinforce emotionality. Initially, the legitimacy of the mediation model was called into question, however, there is now a vast amount of evidence that cognitive interpretations of situations can affect the response to those events, and that there is therapeutic value in altering the content of these situations (e.g., Dobson & Khatri, 2000; Dozois & Beck, 2008). While the concept of meditation is generally accepted, clinicians continue to debate over the degree and exact nature of the interpretations.
The second proposition states that cognitive activity is able to be monitored and altered. This proposition suggests that individuals may gain access to cognitive activity, and that cognitions are knowable (Dobson, 2010). While it is assumed in this statement that cognitive activity is assessable, it should be noted that individuals may report cognitive activities on the basis of their likelihood of occurrence rather than actual occurrence (Dobson, 2010). Researchers in the area of cognitive assessment continue to attempt to document reliable and valid cognitive assessment strategies using behavior as the source of validational data (Dobson, 2010). Therefore, further validation of cognitive reports is required when there is reason to believe that there are biases in cognitive reports.
The second proposition also suggests that alteration of cognitive activity is prefaced by assessment of cognitive activity. While it is rational to assume that a construct must be measured first before it can be manipulated, this is not always the case since measurement of cognition does not necessarily assist with change efforts. This is due to the fact that the majority of cognitive assessment strategies focus on the content of cognitions and the assessment of cognitive results rather than the cognitive process (Dobson, 2010).
The final CBT proposition is also directly related to the mediational model. The proposition states that the desired behavioral change may be effected through cognitive change. Cognitive-behavioral theorists accept that overt reinforcement techniques can alter behavior; however, they often highlight alternative methods for behavioral change, the primary method being cognitive change (Dobson, 2010).
General Approaches to Cognitive-Behavioral Therapy
All treatment approaches within the scope of CBT share the theoretical perspective that assumes that cognitions occur, and that behavior is mediated by these cognitions (Dobson, 2010). Thus, the two main factors used by cognitive-behavioral therapists to measure change are cognition and behavior. Cognitive-behavioral therapists may also use emotional and physiological changes as indicators of change in CBT, especially if a clients presenting problem involves emotional or physiological disturbances (e.g., anxiety disorders) (Dobson, 2010).
Currently there are three major classes of CBTs, each of which deals with a slightly different class of change goals. The three classes are coping skills therapies, problem solving therapies, and cognitive restructuring methods (Dobson, 2010). Each of these different classes of therapy deals with a varying degree of cognitive versus behavioral change. For instance, coping skills therapies tend to be used for problems that are external to the client. Thus, coping skills therapies focus on the identification and alteration of the ways the person may worsen the impact of negative events (e.g., using avoidance) or help the client develop techniques to reduce the impact of negative events (e.g., learning meditation techniques) (Dobson, 2010). Therapeutic progress within this form of therapy can be measured by signs of improved coping skills, and less demonstrated anxiety by the client in light of negative events (Dobson, 2010). While coping skills therapies focus on problems that are external to the client, cognitive restructuring techniques are employed when the disturbance is created from within the client. Overall, cognitive restructuring approaches tend to focus on the long-term beliefs and situation specific automatic thoughts that generate negative outcomes.
Since CBT focuses on both cognition and behavior as primary changes areas, certain types of desired change fall outside of the realm of CBT. For instance, if a therapist uses a classical conditioning approach to treat a child who is acting out in school due to a learning disability, they are not working with in a cognitive-behavioral framework (Dobson, 2010). This is due to that fact that the therapist has focused only on behavior by adopting a stimulus-response model, which is not a CBT (Dobson, 2010). For a treatment to be labeled "cognitive-behavioral" it must exhibit cognitive mediation, and involve cognitive mediation as an important component in the treatment plan. In addition to strictly behavioral therapies not being CBTs, therapies that only focus on cognition are also not CBTs. For example, a therapist who uses a therapeutic model that targets memories of a long-past traumatic event as a way to treat the current emotional disturbances of a client is not practicing CBT (Dobson, 2010). An exception to the above senario would be if client experienced a current event that was similar to a past traumatic event, and the client is experiencing distress due to both the past trauma and current event. In this example, cognitive mediation is more likely, thus the therapy may be cognitive-behavioral in nature (Dobson, 2010).
Lastly, therapies that base their theories in the expression of excessive emotions are not considered to be cognitive-behavioral. An example of this would be cathartic models of therapy (Dobson, 2010). While these therapies may suggest that the emotions develop from negative cognitive mediational processes, they lack a clear mediational model of change which prevents them from being considered CBTs (Dobson, 2010).
Research and Cognitive-Behavioral Therapy
As previously stated, CBT has received a large amount of research attention and considerable support. In a survey conducted by the Task Force on Promotion and Dissemination of Psychological Procedures, CBT was listed as the most frequently endorsed empirically supported treatment across disorders and age groups (Dobson, 2010). Additionally, CBT has become a primary treatment approach, and is one of the most commonly used psychotherapeutic treatments in adults (Leichensring, Hiller, Weissberg, & Leibing, 2006). The remainder of this paper will explore the literature focusing on the efficacy of CBT as it applies to two major diagnoses: mood disorders, and anxiety disorders. It should be noted that Beck's standard cognitive therapy (CT) and various other forms of CBT will be grouped together in this section. The rationale for doing so is that Beck's standard cognitive therapy (Beck, Rush, Shaw, & Emery, 1979), and other combinations of cognitive and behavioral treatments all target change in both cognition and behavior (Dobson, 2010). Thus, for the purposes of this section standard CT and other forms of CBT will all fall under the single category of CBT.
Gloaguen, Cottraux, Cucherat, & Blackburn (1998) conducted a meta-analysis that compared CT groups to comparison groups. The CT treatments included in their studies had to either follow Beck's CT manual or refer explicitly to Beck's model. The comparison groups in their analyses studies included untreated controls; waiting list, pharmacotherapy, and behavioral therapy conditions; and a diverse group of "other therapies." The results of these studies demonstrated strong evidence for the efficacy of CT, and superiority of CT over other therapies. Furthermore, the results suggest that CT was superior to antidepressants, and that behavioral therapy (BT) and CT are equally effective.
A few years after the Gloaguen et al. (1998) study, Wampold, Minami, Baskin, and Tierney (2002) further explored this topic due to their dissatisfaction with the "other therapies" classification used in the in the Gloaguen et al. (1998) study. Wampold et al. (2002) felt that the combination of bona fide and non-bona fide psychotherapies into the "other therapies" category may have invalidated the results. After reanalysis of the Gloaguen et al. (1998) data, Wampold et al. (2002) concluded that CT was approximately as effective as bona fide treatments, but more effective than non-bona fide treatments. Additionally, they found that all bona fide psychological treatments for depression are equally effective.
In an RCT study conducted by DeRubeis et al. (2005) comparing CT and pharmacotherapy in patients with moderate to severe depression, it was found that 24 sessions of CT were as effective as pharmacotherapy. Furthermore, the individuals in the study who received CT were less likely to relapse than those who discontinued medication, and had relapse rates similar to those who continued medication over a 12- month period.
Although pharmacotherapy still remains the primary treatment for bipolar disorder, psychotherapy techniques used in conjunction have been shown to increase quality of life and enhance the patient's motivation to control episodes (Miklowitz & Otto, 2006). In a review conducted by Zaretsky, Rizvi, and Parikh (2007) RCTs of psychoeducation, family-focused therapy, brief CBT interventions, CBT for bipolar disorder, CBT for relapse prevention, interpersonal therapy, and social rhythm therapy where explored. The results of this review suggest that bipolar individuals receiving pharmacotherapy experience increased benefits when it was combined with a short-term, specifically targeted psychotherapy. In addition, CBT, psychoeducation, and family focused therapy produced the most robust relapse prevention effects.
Literature exploring treatment outcomes for specific phobias is somewhat limited. The research that has been conducted is generally not of the highest quality due to uncontrolled designs, small sample sizes, and confusion between strictly behavioral and CBT therapies (Dobson, 2010). In a narrative review of treatment studies conducted by Choy, Fyer, and Lipsitz (2007) they found that treatments are not equally as effective, and that the efficacy of each treatment varies among phobia subtypes. Overall, BTs were supported the most frequently, demonstrating robust acute results for in vivo exposure across the majority of the phobia subtypes.
Social Anxiety Disorder
Bandelow, Seidler-Brandler, Becker, Wedekind, and Rüther (2007) conducted a meta-analysis that compared CBT, pharmacotherapy, and the combination of both in six studies on social anxiety disorder (SAD), 16 studies on panic disorder, and two studies on generalized anxiety disorder. Clinicians in these studies rated pharmacotherapy as the most efficacious overall, however, patients rated the combination of both therapies as being most effective. Mixed results were found for follow-up data investigating the stability of CBT and pharmacotherapy.
In a meta-analysis conducted by Rodebaugh et al. (2004) moderate to large controlled effect sizes for CBT at post treatment were found. Furthermore, they found moderate to large within-group uncontrolled effect sizes for CBT.
CBT and pharmacotherapy have been established as the two primary treatments for obsessive-compulsive disorder, with exposure and response prevention being the most effective form of CBT (OCD; Allen, 2006). Allen (2006) stated that CBT with exposure and response prevention is the only psychotherapy that has been shown to be effective in the treatment of OCD. Allen (2006) also suggests that the combination of CBT and pharmacotherapy is more effective than CBT alone in patients with comorbid depression and OCD.
Panic Disorder with or without Agoraphobia
Bandelow et al. (2007) recently conducted a study comparing CBT, pharmacological, and combined interventions for the treatment of panic disorder with agoraphobia (PDA) or without agoraphobia (PD). Large effect sizes from pre- to posttreatment were found for CBT or pharmacological treatment, and their combination on both clinician and self-report ratings. Overall, subjects reported higher pre-post differences for CBT alone than for drug treatment alone, however, clinicians reported the opposite.
In a literature review by Landon and Barlow (2004) the absolute and relative efficacy of CBT for the treatment of PDA and PD was explored. They found that lengthy CBT is not necessary for effective treatment, and that brief forms of CBT are superior to other forms of psychotherapy. Additionally, they found that pharmacotherapy is the most costly treatment due to the cost of sessions and medications, while CBT is significantly more cost efficient.
Posttraumatic Stress Disorder
A recent meta-analysis conducted by Bisson, Brayne, Ochberg, and Everly (2007) investigated the absolute and relative efficacies of trauma CBT (TFCBT), group CBT, stress management (SM), eye movement desensitization and reprocessing (EMDR), and other therapies (i.e., psychodynamic therapy, hypnotherapy, nondirective counseling, and supportive therapy). The results from this study suggest that individuals receiving TFCBT reported better outcomes than waiting-list and usual care on all measures of PTSD symptoms. In addition, there was some evidence that TFCBT is effective with comorbid depression and anxiety. In a study conducted by the National Collaborating Centre for Mental Health (2005) TFCBT was rated higher than paroxetine for the reduction of PTSD severity, and for reduced depression symptoms on self-rated measures.
Generalized Anxiety Disorder
Hunot, Churchill, Silve de Lima, and Teixeira (2007) conducted a 22 study meta-analysis that focused on generalized anxiety disorder (GAD). In this meta-analysis individuals receiving CBT were more likely to achieve clinical response at posttreatment than those in the treatment as usual group or waiting list control. In the only study included in this meta-analysis that compared the efficacy of CBT to psychodynamic therapy, it was determined that individuals who received CBT were more likely to show a reduction in depressive symptoms and anxiety than those who received psychodynamic therapy at both posttreatment and at 6-month follow-up. Additionally, CBT was more effective than supportive therapy at reducing anxiety and depressive symptoms at posttreatment, and anxiety at 6-month follow-up.