Randomised controlled trials (RCTs) that compared the effects of a pharmacologic intervention alone versus a combined pharmacologic and psychological intervention in adults with diagnosed depressive disorder (major depression, dysthymia) were eligible for inclusion. Studies of in-patients were excluded, as were studies aimed at relapse prevention or maintenance treatments.
The included trials were of adults in general or targeted specific adult groups (older adults or adults who lost their spouse, adult women, patients with comorbid borderline personality disorder, chronic depression or coronary artery disease and women with postpartum depression). Patients were recruited through clinical referrals and/or the community. Psychological treatments varied, but included cognitive-behavioural therapy (CBT), social skills training, interpersonal psychotherapy, psychodynamic psychotherapy, dialectical behaviour therapy, rational-emotive therapy, problem-solving therapy and a treatment initiation programme. Psychological treatments were given individually and/or in groups. The number of sessions ranged from five to 56. Pharmacotherapy included selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants and other medications or a protocol. The most commonly used outcome measures were Beck Depression Inventory (BDI) and Hamilton Rating Scale for Depression (HRSD).
The authors did not state how many reviewers selected trials for inclusion.