Relationship between baseline cognition and 18-month treatment response in bipolar disorder

Background: To date, few studies have examined baseline cognitive function as a predictor of clinical outcome following treatment in bipolar disorder (BD). The aim of this analysis was therefore to examine the relationship between baseline cognitive function and treatment outcome in a sample of young adults with BD receiving Interpersonal Social Rhythm Therapy (IPSRT) or Specialist Supportive Care (SSC) with adjunctive pharmacotherapy. Methods: Eighty-six BD patients underwent baseline cognitive testing and completed 18 months of IPSRT or SCC. Univariate analyses examined the relationship between baseline cognitive function (global and individual cognitive domains) and change in mood symptom burden, and psychosocial functioning, from baseline to treatment-end. Results: Baseline global cognition was not predictive of change in mood symptom burden over 18 months of treatment. However, poorer baseline psychomotor speed performance was associated with less improvement in mood symptom burden at treatment-end. Neither baseline global cognition nor individual cognitive domain scores were associated with change in psychosocial functioning. Limitations: Due to the exploratory nature of the study, correction was not made for multiple comparisons. Data was obtained from a relatively small sample and has been the subject of prior analysis, thereby increasing the likelihood of chance findings. Conclusion: Although global cognition was not associated with outcome, when examining individual domains, poorer baseline psychomotor speed predicted less change in mood symptom burden following 18-months of psychotherapy and pharmacotherapy. This suggests that pre-treatment measures of psychomotor speed may help to identify those who require additional, and more targeted, intervention. Further large-scale research is required.