Impulse control disorder comorbidity among patients with bipolar I disorder.

OBJECTIVE

Impulsivity is associated with mood instability, behavioral problems, and action without planning in patients with bipolar disorder. Increased impulsivity levels are reported at all types of mood episodes. This association suggests a high comorbidity between impulse control disorders (ICDs) and bipolar disorder. The aim of this study is to compare the prevalence of ICDs and associated clinical and sociodemographic variables in euthymic bipolar I patients.

METHOD

A total of 124 consecutive bipolar I patients who were recruited from regular attendees from the outpatient clinic of our Bipolar Disorder Unit were included in the study. All patients were symptomatically in remission. Diagnosis of bipolar disorder was confirmed using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Impulse control disorders were investigated using the modified version of the Minnesota Impulsive Disorders Interview. Impulsivity was measured with the Barratt Impulsiveness Scale Version 11. Furthermore, all patients completed the Zuckerman Sensation-Seeking Scale Form V.

RESULTS

The prevalence rate of all comorbid ICDs in our sample was 27.4% (n = 34). The most common ICD subtype was pathologic skin picking, followed by compulsive buying, intermittent explosive disorder, and trichotillomania. There were no instances of pyromania or compulsive sexual behavior. There was no statistically significant difference between the sociodemographic characteristics of bipolar patients with and without ICDs with regard to age, sex, education level, or marital status. Comorbidity of alcohol/substance abuse and number of suicide attempts were higher in the ICD(+) group than the ICD(-) group. Length of time between mood episodes was higher in the ICD(-) group than the ICD(+) group. There was a statistically significant difference between the total number of mood episodes between the 2 groups, but the number of depressive episodes was higher in the ICD(+) patients as compared with the ICD(-) patients. There was no statistically significant difference between the age of first episode, seasonality, presence of psychotic features, and chronicity of illness. A statistically significant difference was observed between the ICD(+) and ICD(-) groups in terms of total impulsivity, attention, nonplanning, and motor impulsivity scores as determined by the Barratt Impulsiveness Scale Version 11.

CONCLUSION

The present study revealed that there is a high comorbidity rate between bipolar disorder and ICDs based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, criteria. Alcohol/substance use disorders, a high number of previous suicide attempts, and depressive episodes should alert the physician to the presence of comorbid ICDs among bipolar patients that could affect the course and treatment of the disorder.