A randomised controlled trial of psychotherapy and cognitive remediation to target cognition in mood disorders

Objective To examine the impact of a treatment package combining Interpersonal and Social Rhythm Therapy (IPSRT) and cognitive remediation (CR), vs IPSRT alone, on cognition, functioning, and mood disturbance outcomes in mood disorders. Methods A pragmatic randomised controlled trial in adults with bipolar disorder (BD) or major depressive disorder (MDD), recently discharged from mental health services in Christchurch, New Zealand, with subjective cognitive difficulties. Individuals were randomised to a 12‐month course of IPSRT with CR (IPSRT‐CR), or without CR (IPSRT). In IPSRT‐CR, CR was incorporated into therapy sessions from approximately session 5 and continued for 12 sessions. The primary outcome was change in Global Cognition (baseline to 12 months). Results Sixty‐eight individuals (BD n = 26, MDD n = 42; full/partial remission n = 39) were randomised to receive IPSRT‐CR or IPSRT (both n = 34). Across treatment arms, individuals received an average of 23 IPSRT sessions. Change in Global Cognition did not differ between arms from baseline to treatment‐end (12 months). Psychosocial functioning and longitudinal depression symptoms improved significantly more in the IPSRT compared with IPSRT‐CR arm over 12 months, and all measures of functioning and mood symptoms showed moderate effect size differences favouring IPSRT (0.41–0.60). At 18 months, small to moderate, non‐significant benefits (0.26–0.47) of IPSRT vs IPSRT‐CR were found on functioning and mood outcomes. Conclusions Combining two psychological therapies to target symptomatic and cognitive/functional recovery may reduce the effect of IPSRT, which has implications for treatment planning in clinical practice and for CR trials in mood disorders.