Numerous studies have been conducted of CT. The studies described below (meta-analyses and peer-reviewed, published articles) are a selection of those that examined the long-term effects of CT.
Several meta-analyses have been conducted on CT:
- Dobson, K. S. (1989). A meta-analysis of the efficacy of Cognitive Therapy for depression. Journal of Consulting and Clinical Psychology, 57, 414-419.
- Gaffan, E. A., Tsaousis, I., & Kemp-Wheeler, S. M. (1995) Researcher allegiance and meta-analysis: The case of Cognitive Therapy for depression. Journal of Consulting and Clinical Psychology, 63, 966–980.
- Gloaguen, V., Cottraux, J., Cucherat, M., & Blackburn, I. (1998). A meta-analysis of the effects of Cognitive Therapy in depressed patients. Journal of Affective Disorders, 49, 59-72.
Evans, M. D., Hollon, S. D., Garvey, M. J., Piasecki, J. M., Grove, W. M., Garvey, M. J., & Tuason, V. B. (1982). Differential relapse following Cognitive Therapy and pharmacotherapy for depression. Archives of General Psychiatry; 49, 802–808.
Type of Study: Randomized controlled trial
Number of Participants: 50
Population:
- Age range — Not specified, listed as "early 30s"
- Race/Ethnicity — Not specified, listed as primarily White
- Gender — Not specified, listed as primarily female
- Status — Nonbipolar, nonpsychotic depressed outpatients requesting treatment for depression.
Location / Institution: Department of Psychology, University of Minnesota, Minneapolis and Department of Psychiatry St Paul – Ramsey Medical Center
Summary: (To include comparison groups, outcomes, measures, notable limitations)
Patients successfully treated during a 3-month period with either imipramine hydrochloride pharmacotherapy, Cognitive Therapy (CT), or combined CT and pharmacotherapy were monitored during a 2-year posttreatment follow-up period. Half of the patients treated with pharmacotherapy alone continued to receive study medications for the first year of the follow-up. All other patients discontinued treatment at the end of the acute treatment phase. Measures included the Beck Depression Inventory, the Hamilton Rating Scale for Depression, and the Raskin Depression Scale. Patients treated with CT (either alone or in combination with medication) evidenced less than half the rate of relapse shown by patients in the medication--no continuation condition, and their rate did not differ from that of patients provided with continuation medication. It appears that providing CT during acute treatment prevents relapse.
Length of post-intervention follow-up: 2 years post-treatment.
Blackburn, I. M., & Moore, R. G. (1997). Controlled acute and follow-up trial of Cognitive Therapy and pharmacotherapy in out-patients with recurrent depression. British Journal of Psychiatry, 171, 328–334.
Type of Study: Randomized controlled trial
Number of Participants: 75
Population:
- Age range — Mean age range 37.8 – 40.1 years
- Race/Ethnicity — Not Specified
- Gender — Not Specified
- Status — Patients were recruited from out-patient referrals to consultants in a large teaching psychiatric hospital, and from two general practices.
Location / Institution: Department of Psychiatry. University of Edinburgh
Summary: (To include comparison groups, outcomes, measures, notable limitations)
Patients were allocated to three groups: 6 weeks of acute treatment and two years' maintenance treatment in the following way: antidepressants and maintenance antidepressants; Cognitive Therapy (CT) and maintenance cognitive therapy; antidepressants and maintenance cognitive therapy. Both completers' and end-point data were analyzed. In the acute phase of treatment, all patients improved significantly and there was no significant difference among treatments, or in the pattern of improvement over time. In the maintenance stage of treatment, patients kept improving over time in all three groups and there was no significant difference among treatments. CT was consistently superior to medication. The results indicate that maintenance cognitive therapy has a similar prophylactic effect to maintenance medication and is a viable option for maintenance after acute treatment with medication in recurrent depression.
Length of post-intervention follow-up: 20 months after end of acute phase.
Paykel, E. S., Scott, J., Teasdale, J. D., Johnson, A. L., Garland, A., Moore, R., … Pope, M. (1999). Prevention of relapse in residual depression by Cognitive Therapy: A controlled trial. Archives of General Psychiatry, 56, 829-835.
Type of Study: Randomized controlled trial
Number of Participants: 158
Population:
- Age range — Mean age: 43 years
- Race/Ethnicity — Not Specified
- Gender — 50% male
- Status — Participants were recruited from psychiatric outpatient clinics in Cambridge and Newcastle, England.
Location / Institution: Departments of Psychiatry, University of Cambridge, Cambridge, England; University of Glasgow, Glasgow, Scotland; University of Newcastle, Newcastle, England; and MRC Cognition and Brain Sciences Unit and Medical Research Council Biostatistics Unit, University of Cambridge Institute of Public Health.
Summary: (To include comparison groups, outcomes, measures, notable limitations)
Patients with recent major depression, partially remitted with antidepressant treatment but with residual symptoms of 2 to 18 months’ duration, were randomized to receive clinical management alone or clinical management plus Cognitive Therapy (CT) for 16 sessions during 20 weeks, with 2 subsequent booster sessions. Subjects were assessed regularly throughout the 20 weeks’ treatment and for a further year; measures included the Hamilton Rating Scale for Depression and the Beck Depression Inventory. They received continuation and maintenance antidepressants at the same dose throughout. CT reduced relapse rates for acute major depression and persistent severe residual symptoms, in both intention to treat and treated per protocol samples. The cumulative relapse rate at 68 weeks was reduced significantly from 47% in the clinical management control group to 29% with CT. CT also increased full remission rates at 20 weeks but did not significantly improve symptom ratings.
Length of post-intervention follow-up: 1 year after end of treatment.
Bockting, C. L. H., Schene, A. H., Spinhoven, P., Koeter, M. W. J., Wouters, L. F., Huyser, J., & Kamphuis, J. H. (2005). Preventing relapse/recurrence in recurrent depression with Cognitive Therapy: A randomized controlled trial. Journal of Consulting and Clinical Psychology, 73, 647-657.
Type of Study: Randomized controlled trial
Number of Participants: 187
Population:
- Age range — Mean age: Treatment: 45.9 years Control: 43.4 years
- Race/Ethnicity — 98-99% White
- Gender — Not Specified
- Status — Participants were recruited from February 2000 through September 2000 at psychiatric centers (31% of the participants) and through media announcements (69% of the participants) in the Netherlands.
Location / Institution: Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
Summary: (To include comparison groups, outcomes, measures, notable limitations)
This article reports on the outcome of a randomized controlled trial of group Cognitive Therapy (CT) to prevent relapse/recurrence in high-risk patients diagnosed with recurrent depression. Recurrently depressed patients currently in remission and following various types of treatment were randomized to treatment as usual, including continuation of pharmacotherapy, or to treatment as usual augmented with brief CT. Relapse/recurrence to major depression was assessed over 2 years. Measures included the Structured Clinical Interview for DSM–IV, the Hamilton Rating Scale for Depression (HRSD), the Dysfunctional Attitude Scale, and the Everyday Problem Checklist. Augmenting treatment as usual with CT resulted in a significant protective effect, which intensified with the number of previous depressive episodes experienced. For patients with 5 or more previous episodes (41% of the sample), CT reduced relapse/recurrence from 72% to 46%. The findings extend the accumulating evidence that cognitive interventions following remission can be useful in preventing relapse/recurrence in patients with recurrent depression.
Length of post-intervention follow-up: 2 years.
Hollon, S. D., DeRubeis, R. J., Shelton, R. C., Amsterdam, J. D., Salomon, R. M., O’Reardon, J. P., … Gallop, R. (2005). Prevention of relapse following cognitive therapy vs. medications in moderate to severe depression. Archives of General Psychiatry, 62, 417-422.
Type of Study: Follow-up to a randomized controlled trial
Number of Participants: 104
Population:
- Age range — Mean age: 40 years
- Race/Ethnicity — 82% White
- Gender — 59% female
- Status — Participants were patients with moderate to severe unipolar depression aged 18 to 70 years who were recruited from outpatient psychiatric clinics.
Location / Institution: Outpatient clinics at the University of Pennsylvania and Vanderbilt University.
Summary: (To include comparison groups, outcomes, measures, notable limitations)
Patients who responded to CT in a randomized controlled trial were withdrawn from treatment and compared during a 12-month period with medication responders who had been randomly assigned to either continuation medication or placebo withdrawal. Patients who survived the continuation phase without relapse were withdrawn from all treatment and observed across a subsequent 12-month naturalistic follow-up. Relapse was defined as a return, for at least 2 weeks, of symptoms sufficient to meet the criteria for major depression or Hamilton Rating Scale for Depression scores of 14 or higher during the continuation phase. Recurrence was defined in a comparable fashion during the subsequent naturalistic follow-up. Patients withdrawn from CT were significantly less likely to relapse during continuation than patients withdrawn from medications, and no more likely to relapse than patients who kept taking continuation. There were also indications that the effect of CT extends to the prevention of recurrence.
Length of post-intervention follow-up: 2 years.
Floyd, M., Rohen, N., Shackelford, J. A. M., Hubbard, K. L., Parnell, M. B., Scogin, F., & Coates, A. (2006). Two-year follow-Up of bibliotherapy and individual Cognitive Therapy for depressed older adults. Behavior Modification, 30, 281-294.
Type of Study: Randomized controlled trial
Number of Participants: 23
Population:
- Age range — 60 years of age or older
- Race/Ethnicity — Not Specified
- Gender — Not Specified
- Status — Older adults recruited from the community
Location / Institution: Tuscaloosa, Alabama, and Birmingham, Alabama
Summary: (To include comparison groups, outcomes, measures, notable limitations)
This study examined the stability of treatment gains after receiving either cognitive bibliotherapy or individual Cognitive Therapy (CT) for depression in older adults. A 2-year follow-up of participants was conducted by comparing pre- and posttreatment scores with follow-up scores on the Hamilton Rating Scale for Depression (HRSD) and the Geriatric Depression Scale (GDS). Results indicated that treatment gains from baseline to the 2-year follow-up period were maintained on the HRSD and GDS, and there was not a significant decline from posttreatment to follow-up. There were no significant differences between the treatments on the GDS or HRSD at the 2-year follow-up; however, bibliotherapy participants had significantly more recurrences of depression during the follow-up period.
Length of post-intervention follow-up: 2 years.
Dobson, K. S., Hollon, S. D., Dimidjian, S., Schmaling, K. B., Kohlenberg, R. J., Gallop, R. J., Rizvi, S. L., … Jacobson, N. S. (2008). Randomized trial of behavioral activation, Cognitive Therapy, and antidepressant medication in the prevention of relapse and recurrence in major depression. Journal of Consulting and Clinical Psychology, 76(3), 468-477.
Type of Study: Randomized controlled trial
Number of Participants: 241
Population:
- Age range — Mean age 39.9 years
- Race/Ethnicity — 81.7% Caucasian
- Gender — Not Specified
- Status — Participants for this study consisted of adult outpatients who responded to acute phase treatment for depression from the Dimidjian et al. (2006) study.
Location / Institution: Seattle, WA
Summary: (To include comparison groups, outcomes, measures, notable limitations)
This study followed treatment responders from a randomized controlled trial of adults with major depression. Patients treated with medication but withdrawn onto pill-placebo had more relapse through 1 year of follow-up compared to patients who received prior behavioral activation, prior Cognitive Therapy (CT) , or continued medication. Measures included the Beck Depression Inventory II and the Hamilton Rating Scale for Depression. Prior psychotherapy was also superior to medication withdrawal in the prevention of recurrence across the 2nd year of follow-up. Specific comparisons indicated that patients previously exposed to CT were significantly less likely to relapse following treatment termination than patients withdrawn from medication, and patients previously exposed to behavioral activation did almost as well relative to patients withdrawn from medication, although the difference was not significantly different. Differences between behavioral activation and CT were small in magnitude and not significantly different across the full 2-year follow-up, and each therapy was at least as efficacious as the continuation of medication. These findings suggest that behavioral activation may be nearly as enduring as CT and that both psychotherapies are less expensive and longer lasting alternatives to medication in the treatment of depression.
Length of post-intervention follow-up: 2 years.
