Cognitive Behavioral Therapy for Depression and Anxiety Disorders
Cognitive behavioral therapy (CBT) is perhaps one of the most frequently used psychotherapeutic orientations, with considerable research supporting its effectiveness and adaptability in clinical practice. As the name implies, CBT integrates the rationale and techniques from both cognitive therapy and behavioral therapy, taking advantage of their complimentary relationship.1 For example, as cognitive therapy seeks to change behavior by challenging maladaptive thoughts, behavioral therapy employs more direct, yet complimentary methods, such as pairing reinforcing stimuli with a desired behavior or aversive stimuli with an undesired behavior.1–3 While the efficacy of CBT has been firmly established in the treatment of a variety of disorders and problems, its history and utility are deeply rooted in the treatment of anxiety and depression symptoms.3 Aaron T. Beck4 is recognized as the father of CBT, and his theory evolved from helping depressed patients recognize their faulty automatic thoughts that negatively affect their behavior. In contrast to other forms of psychotherapy, CBT aims to quickly resolve maladaptive thoughts or behaviors without necessarily delving too deeply into why they may occur. Thus, effective courses of therapy might be as short as a single session, or as long as a lifetime, depending on the specific needs of the individual.1 CBT helps individuals deal with their difficulties by changing their thinking patterns, behaviors, and emotional responses.4
This report summarizes evidence gained from systematic reviews focusing on the efficacy of CBT in the treatment of depression and anxiety disorders; that is, panic disorder with or without agoraphobia, specific phobia, social phobia, generalized anxiety disorder (GAD), obsessive compulsive disorder (OCD), posttraumatic stress disorder (PTSD), acute stress disorder (ASD), substance-induced anxiety disorder, anxiety disorder related to a general medical condition, and anxiety disorder not otherwise specified.5 The report contains reviews assessing the efficacy of CBT on individuals diagnosed with depression and/or anxiety disorder and individuals suffering from symptoms of anxiety or depression who may not have been diagnosed with these disorders.
Search Strategy and Criteria
An extensive search was conducted for systematic reviews published. The search was limited to the online catalog of the U.S. Government’s National Library of Medicine, PubMed to ensure free access to abstracts, and in some cases, full-text articles. Systematic reviews reported in the context of guidelines, consensus statements, or studies were not the target of the search.
The strategy used to conduct the search appears below and consists of several parts: "Cognitive Therapy"[Majr] AND (systematic[sb] OR Meta-Analysis[pt]) AND “English”[lang] AND “Humans”[MeSH Terms] AND [PDAT]: [PDAT]
Each part of the strategy is described below:
- Topics: The PubMed Medical Subject Heading (MeSH), "Cognitive Therapy" was used to limit the search to systematic reviews that included a review of CBT. The [Majr] designation further restricted the search to those reviews focusing specifically on CBT. Reviews focusing on symptoms of anxiety or depression were then hand-picked from the articles retrieved.
- Additional limits: Limits were used restricting the search to systematic reviews (with a separate designation for those containing meta-analyses) and articles published in English, focusing on humans.
The literature search yielded a total of 18 systematic reviews assessing the effectiveness of CBT in treating depression and anxiety disorders. Of the 18 reviews, 16 included meta-analyses (Reviews 1–12, 14–16, and 18). The average number of studies included in the systematic reviews was 22 (range = 4–65; median = 15). Studies were conducted in the United States and internationally. Most of the studies did not specify the settings where the psychological interventions were carried out; however, for those that reported, settings included outpatient setting, inpatient setting, mental health clinics, private practices, homes, and prisons. The study populations consisted of adolescents, adults, and older adults with depressive disorder or symptoms, major depressive disorder, and anxiety disorders (i.e., GAD, social anxiety disorder, panic disorder, OCD, PTSD, and ASD). One systematic review focused on the treatment of anxiety disorders (i.e., OCD, panic disorder, PTSD) symptoms in Cambodian or Vietnamese refugees (Review 13). The objective of most systematic reviews was to examine the effectiveness of CBT in treating depression and anxiety disorders. Some reviews also assessed whether the efficacy of CBT is affected by the mode of treatment delivery (e.g., computer, individual versus group therapy) or the age of the patients.
CBT Treatment Effects Compared to Other Therapies
CBT is as effective, or more effective, than other psychological therapies examined, such as general psychotherapy, stress management, problem-solving therapy, and reminiscence therapy, in the treatment of adults with anxiety and depression (Reviews 1 and 11). Systematic reviews examining the effectiveness of pharmacotherapy and CBT on anxiety and depressive disorders found mixed results. In particular, some evidence suggested pharmacotherapy is more effective than CBT in treating anxiety and depression, while patients with panic disorder had better results with CBT than pharmacotherapy. Although there are modest differences, at best, in the efficacy of pharmacotherapy and CBT, CBT was identified as an effective next-step strategy in the treatment of some anxiety disorders (i.e., OCD, PTSD, panic disorder) in patients whose symptoms do not remit solely with pharmacotherapy (Review 13). Moreover, there is evidence to suggest CBT is better tolerated than pharmacotherapy in treating patients with anxiety disorders.
CBT Delivery and Treatment Effects
Five systematic reviews assessed the efficacy of self-administered CBT or computer-based CBT (Reviews 2, 9, 12, 15, and 17). Self-help CBT-based materials were effective in treating mild to moderate anxiety or depressive disorders at posttreatment, but not at follow-up. The benefits of computer-based CBT in treating patients with anxiety disorders were large, and one systematic review demonstrated that improvements in OCD symptoms persisted even beyond the end of the therapy. Although there is some evidence to suggest computer-based CBT is effective for treating depression, the benefits of the therapy are greatly enhanced when minimal therapist support is also provided. Although two reviews (Reviews 1 and 3) found individual CBT to be more efficacious in treating anxiety and depression than group CBT, group therapy was still effective in treating GAD, and the benefits were well maintained 1 year after treatment.
CBT for Depression and Anxiety in Older Adults
Three systematic reviews (Reviews 3, 6, and 11) concluded that older adults with anxiety or depressive disorders responded well to CBT, suggesting CBT is effective for treating anxiety and depression late in life. These findings support the applicability of CBT to a variety of populations and for specific developmental stages of life.
Overall, the effectiveness of CBT has been examined in patients with anxiety disorders more frequently than in patients with depressive disorders. Therefore, the efficacy of CBT in the treatment of anxiety disorders is more strongly supported than in the treatment of depressive disorders.