Are self-rated and behavioural measures of impulsivity in bipolar disorder mainly related to comorbid substance use problems?

ABSTRACT

Introduction: Impulsivity is a multidimensional feature observed in bipolar disorder (BD) and substance use disorder (SUD). We previously found a relationship between SUD and risk taking in BD. It is still unclear whether self-rated and behavioral impulsivity measures differ between BD with and without comorbid SUD, or are specific to BD.

Methods: 93 adults with BD with comorbid SUD, 91 BD without SUD, and 93 healthy controls (HC) were administered the Barratt Impulsivity Scale (BIS), the Behavioral Inhibition/Behavioral Activation System Scale (BIS/BAS), and the Cambridge Neuropsychological Test Automated Battery. Analyses compared impulsivity measures across groups controlling for age. Discriminant function analyses (DFA) assessed the combination of variables effectively predicting group membership.

Results: BD displayed increased BIS, BIS/BAS scores, reduced performance on the Cambridge Gambling and Rapid Visual Processing, and Affective Go/No-Go tasks compared to HC. Comparisons between BD with and without SUD showed increased BIS Motor impulsiveness. The overall predictive power of DFA was weak.

Conclusions: Some facets of impulsivity are a core trait of BD and are partially independent from the presence of SUD. Motor impulsiveness may be distinctive of BD+SUD. More research is needed to understand the role of impulsive behaviors as risk factors for relapse in SUD.

KEYWORDS:

• Impulsivity
• bipolar disorder
• substance abuse
• CANTAB

Acknowledgements

MS, DS, GZS, and JCS designed the study, wrote the protocol, and collected the data. IB and TDM undertook the statistical analysis. IB wrote the first draft of the manuscript. All authors contributed to and have approved the final manuscript.

Disclosure statement

Drs Bauer, Meyer, Spiker, and Zunta-Soares have no conflicts of interest. Dr Sanches has received research grants from Janssen. Professor Thomas D. Meyer acted as a speaker for Pfizer and Lundbeck in the past. Dr J. C. Soares has received grants/research support from Forrest, BMS, Merck, J&J, Stanley Medical Research Institute, NIH and has been a speaker for Pfizer and Abbott.

Additional information

Funding

This work was partly supported by the Stanley Medical Research Institute; the Dunn Foundation; National Institutes of Mental Health [grant number MH 085667] (JCS), [grant number R01MH068766], and [grant number K24 RR020571]; and by the Pat Rutherford Jr. Chair in Psychiatry (UTHealth).