Impulsivity, decision-making and risk behavior in bipolar disorder and major depression in bipolar multiplex families.

Introduction: It is not clear whether in families with a marked genetic risk for bipolar disorder (BD) there are impairments in impulsivity, risk behavior and decision making in BD and major depressive disorder (MDD). Objectives: To analyze differences in impulsivity, decision making and risk behavior in bipolar multiplex family members diagnosed with BD, MDD and a healthy control group (HC). Methods: A sample of 8 bipolar multiplex families of an ongoing study (ABIF) was used. A group with a diagnosis of BD (N =31), another with a diagnosis of MDD (N = 26) and finally a HC group (N = 31) from the families and the community were compared. The Stop Signal Task and the Cambridge Gambling Task from the CANTAB battery were used. Mixed logistic regression adjusted by age and gender was carried out. Family structure was included as a random effect using a genetic relationship matrix. The analysis was carried out in R using the function relmatLmer of the package lme4qtl4. Results: There were significant differences between BD and HC, with higher delay aversion (p = 0.032) in BD and marginally significant results with worse response inhibition (p = 0.057) and decision making (p = 0.057) in BD. No differences were found in risk behavior (p = 0.181). There were no significant differences between BD and MDD and between MDD and HC in any variable. Conclusions: In bipolar multiplex families specific deficits were found in impulsivity in individuals with BD. Larger studies are needed to detect smaller effects. [ABSTRACT FROM AUTHOR]