The effect of adding psychodynamic therapy to antidepressants in patients with major depressive disorder. A systematic review of randomized clinical trials with meta-analyses and trial sequential analyses

BACKGROUND: Major depressive disorder afflicts an estimated 17% of individuals during their lifetimes at tremendous suffering and costs. Psychodynamic therapy may be a treatment option for depression, but the effects have only been limitedly assessed in systematic reviews. METHOD: Using Cochrane systematic review methodology, we compared the benefits and harms of psychodynamic therapy versus 'no intervention' or sham for major depressive disorder. We accepted any co-intervention, including antidepressants, as long as it was delivered similarly in both intervention groups. Trials were identified by searching the Cochrane Library's CENTRAL, MEDLINE via PubMed, EMBASE, Psychlit, Psyc Info, and Science Citation Index Expanded until February 2010. Two authors independently extracted data. We evaluated risk of bias to control for systematic errors. We conducted trial sequential analysis to control for random errors. RESULTS: We included five trials randomizing a total of 365 participants who all received antidepressants as co-intervention. All trials had high risk of bias. Four trials assessed 'interpersonal psychotherapy' and one trial 'short psychodynamic supportive psychotherapy'. Meta-analysis showed that psychodynamic therapy significantly reduced depressive symptoms on the 17-item Hamilton Rating Scale for Depression (mean difference -3.01 (95% confidence interval -3.98 to -2.03; P