RISKY DECISION-MAKING IMPAIRMENT IN EARLY-STAGE PSYCHOTIC BIPOLAR DISORDER

Abstract

Background: Previous research suggests that bipolar disorder may be associated with increased risk-taking / impulsivity. Risky decision-making paradigm is an objective, performance-based measure which has been increasingly applied in bipolar disorder research examining. Nonetheless, literature focused only on chronically ill samples, with illness chronicity, clinical heterogeneity and prolonged medication exposure being potential confounding factors of study results. The current study aimed to explore whether patients with early-stage psychotic bipolar disorder (BDP) exhibit impaired risky decision-making relative to healthy controls, using a well-validated, widely-applied experimental paradigm of Balloon Analogue Risk Task (BART). Methods: Thirty-nine patients with early-stage BDP (defined by having received psychiatric treatment for first-episode BDP within 3 years since service entry) and 36 demographically matched healthy controls were recruited. BART was administered to examine risky decision-making performance. Deliberative risky behavior was operationalized as the willingness to inflate balloons as each pump was accompanied by an extra point gained in the temporary repository or balloon explosion. Three performance-based indices (adjusted score, explosion rate and cumulative score) were derived and analyzed. Results: There were no significant differences between patients and controls in age, gender and educational levels. Independent samples t-tests illustrated that patients had significantly lower adjusted score (t = -3.45, p = .001, d = .791), explosion rate (t = -2.75, p = .007, d = .631) and cumulative score (t = -3.07, p = .003, d = .714) in BART compared to controls. Similar findings were obtained when comparison analyses were restricted to patients who were treated with antipsychotic medications at the time of study assessment (n = 30). No significant correlations between BART performance-based indices and measures of clinical and treatment variables were found in patient sample. Discussion: Our results demonstrated that early-stage BDP patients displayed suboptimal risky decision-making compared with controls. Abnormal risky decision-making observed in the euthymic state of patients in early stage of bipolar disorder suggests that such impairment might represent a trait factor in the disorder. Further prospective research is warranted to clarify the longitudinal course of risky decision-making impairment in bipolar disorder.