Cognitive-behavioral therapy (CBT) has received an enormous amount of research attention (+Butler et al. 2006) and has been identified as an empirically supported therapy for numerous psychiatric disorders and medical conditions with psychological components. It is one of the most commonly used psychotherapeutic treatments in adults (+Leichsenring et al. 2006). Surveys indicate that CBT is expected to remain among the foremost foci of psychotherapy training in the coming years, and its importance in the field of psychotherapy is likely to increase (+Norcross et al. 2002). In this chapter we review applications of individual CBT to a variety of psychiatric disorders and review their efficacy and indications. We also discuss the limitations of and knowledge gaps within the current empirical literature, and present suggestions for future research and applications.

The clinical efficacy of a given treatment can be determined through various methods (+Chambless and Ollendick 2001; +Institut National de la Santé et de la Recherche Médicale 2004), but the "gold standard" in psychotherapy research has become the randomized controlled trial (RCT). RCTs can evaluate whether the therapeutic effects of a particular intervention are at least as good as other available interventions and better than no intervention at all. The advantage to conducting efficacy research is that it is well controlled and the results are relatively comparable across studies. Efficacy differs from effectiveness: the former refers to the outcomes of a treatment within an experimental setting: the latter refers to the outcomes of a treatment in the real world of actual clinical practice (+Kazdin 2003).

There are three types of CBT efficacy studies for psychiatric disorders:

Because of the wealth of efficacy literature for CBT, several studies have employed meta-analysis in an attempt to aggregate the available data (+Kazdin 2003). Although meta-analysis tends to minimize the variable methodological details across studies, its strong advantage is that it takes into account the sample size and the magnitude of the effect size for the interventions compared in each study (+Rosenthal 1998). The following précis relies predominantly on the results of meta-analyses. Findings from recent single RCTs are also reported where appropriate. When findings from RCTs are lacking, controlled outcome studies are described.

CBT has been evaluated as a treatment for a broad range of anxiety disorders and typically includes psychoeducation, cognitive restructuring, and exposure to the anxiety-provoking stimulus, situation, memory, or physiological experience (+Barlow 2004).

Several meta-analytic reviews of the treatment outcome literature for panic disorder with or without agoraphobia have been conducted in the past decade, although some meta-analyses have exclusively examined behavioral treatments. +Oei et al. (1999) conducted both a qualitative and a quantitative review of the literature. They found that CBT was efficacious at reducing self-reported agoraphobic symptoms and that its clinical efficacy was substantially demonstrated with community norms. They did not draw any definitive conclusions about the long-term efficacy of CBT, although they noted that different forms of CBT may vary in the minimum periods of time necessary for change. Results of their qualitative review demonstrated that CBT is associated with significant and positive changes on several measures (e.g., panic, fear, avoidance, anxiety, and depression) immediately posttreatment and at follow-up periods of up to 16 months. +Gould et al. (1995) conducted a standard meta-analysis comparing pharmacotherapy, CBT, their combination, and a control (no treatment, waiting list, a placebo pill, or psychological placebo), for panic disorder with or without agoraphobia. All three types of active treatment were superior, in acute treatment, to control conditions. Long-term treatment effects were roughly equal to acute treatment effects, although assessment times were not reported.

CBT, including cognitive restructuring and exposure elements, is the standard approach in treating panic disorder (+Butler et al. 2006). +Gould et al. (1995) found this combination to be the most efficacious of the treatments they investigated. They also found that pharmacotherapy combined with CBT was not as efficacious as CBT alone. They noted, however, that selective serotonin reuptake inhibitors (SSRIs) are more efficacious at treating panic disorder than benzodiazepines and other commonly used antidepressants. Thus, the efficacy of the combination of SSRIs and CBT needs to be studied. +Gould et al. (1995) also found that patients treated with pharmacotherapy alone experienced the greatest reduction of treatment effects over time. In contrast, the combination of CBT plus pharmacotherapy as well as CBT alone typically resulted in maintenance of treatment gains. Two more recent meta-analyses (+van Balkom et al. 1997 and, in a later analysis of the same studies, +Bakker et al. 1998) demonstrated that although CBT was superior to pill placebo, attention placebo, and waiting list, the most efficacious acute treatment method was the combination of antidepressants and in vivo exposure. The psychotherapeutic and pharmacotherapeutic treatment gains for panic disorder patients with and without agoraphobia, over an average follow-up of 62 weeks, tended to be stable.

Treatments for social phobia frequently include exposure, social skills training, cognitive restructuring, or a combination of these strategies (+Deacon and Abramowitz 2004). +Gould et al. (1997a) conducted a meta-analytic review of the efficacy of CBT and pharmacotherapy for social phobia. They examined how treatment improved social anxiety or avoidance, cognition, and depression. All forms of both group and individual CBT were superior to no treatment, a waiting-list condition, or psychological placebo. Analyses based on the within-group changes from posttreatment to follow-up indicated that modest improvements were still present 3 months after treatment only in the CBT group. These findings replicated those of +Feske and Chambless (1995), whose meta-analytic review of treatment outcome studies (group and individual treatment) suggested that exposure alone and exposure plus cognitive restructuring are superior to one of several control conditions, usually a waiting-list condition.

Exposure therapies alone and in combination with cognitive restructuring have been found to be equally efficacious in the treatment of social phobia (+Feske and Chambless 1995; +Gould et al. 1997a). In addition, +Gould et al. (1997a) found that exposure therapies alone and in combination with cognitive restructuring were more efficacious than cognitive restructuring alone. +Fedoroff and Taylor (2001), whose meta-analytic review was more recent than that of Feske and Chambless, concluded that although exposure therapy demonstrated the largest treatment effects at posttreatment compared with cognitive therapy alone or exposure plus cognitive therapy, these effects were not significantly different from zero. It is likely that small sample sizes masked the effects of exposure alone in this study (+Deacon and Abramowitz 2004). Furthermore, +Gould et al. (1997a) found that CBT alone, pharmacotherapy alone, and CBT and pharmacotherapy in combination were equally efficacious. Few studies have compared CBT with other psychotherapies in the treatment of social phobia. In an exception, +Cottraux et al. (2000) found that CBT was superior to supportive therapy. Treatment effects for CBT were sustained at 36- and 60-week follow-ups, but the long-term effects of supportive therapy were not assessed.