Adherence to medication is associated with non-planning impulsivity in euthymic bipolar disorder patients

Adherence to medication is a major issue in bipolar disorder. Non-planning impulsivity, defined as a lack of future orientation, has been demonstrated to be the main impulsivity domain altered during euthymia in bipolar disorder patients. It was associated with comorbidities.

To investigate relationship between adherence to medication and non-planning impulsivity, we included 260 euthymic bipolar patients. Adherence to medication was evaluated by Medication Adherence Rating Scale and non-planning impulsivity by Barrat Impulsiveness Scale. Univariate analyses and linear regression were used. We conducted also a path analysis to examine whether non-planning impulsivity had direct or indirect effect on adherence, mediated by comorbidities.

Adherence to medication was correlated with non-planning impulsivity, even after controlling for potential confounding factors in linear regression analysis (Beta standardized coefficient = 0.156; p = 0.015). Path analysis demonstrated only a direct effect of non-planning impulsivity on adherence to medication, and none indirect effect via substance use disorders and anxiety disorders.

Our study is limited by its cross-sectional design and adherence to medication was assessed only by self-questionnaire.

Higher non-planning impulsivity is associated with low medication adherence, without an indirect effect via comorbidities.