Comorbidity of Impulse Control Disorders Among Patients with Major Depression

Objective: The aim of this study was to determine the prevalence rates of impulse control disorders among patients with major depression and evaluate the effect of comorbidity on the onset and the clinical course of depression. Methods: The study included 150 consecutive depressive psychiatric patients who have presented to our outpatient clinics within a one-year period. A demographic data form has been completed along with a structural clinical interview (SCID-I) to evaluate axis I psychiatric disorders according to the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV). To determine the impulse control disorders and depression, the Minnesota Impulse Control Disorders Interview and the Hamilton Depression Rating Scale have been applied to all patients. Besides, all patients completed the Symptom Check List-90, the Beck Depression Inventory, the Zuckerman's Sensation Seeking Scale Form-V, the Barratt Impulsiveness Scale-11 and the Mood Disorders Questionnaire to help us find out the levels of psychopathology. Results: In a one-year period, 34.7% of depressive outpatients in our clinics had at least one comorbid impulse control disorder. The inclusion of patients with a diagnosis of impulse control disorders not otherwise specified increased the rate of comorbid impulse control disorders to 56.7%. The most common impulse control disorder in our sample was intermittent explosive disorder (31.3%) followed by skin picking (28%) and compulsive buying (14%). Depressive patients with a comorbid impulse control disorder had an earlier age of onset of the disorder than patients without any impulse control disorder. There were no differences between the groups in terms of gender, marital status, education level and number of hospitalizations. Pathological gambling was more common in male patients, whereas compulsive buying was more frequently seen in female patients. Lifetime suicide attempt rates were two times more common in depressive patients with comorbid impulse control disorder than in patients without it, but this difference did not reach statistical significance. Though there was not any statistically significant difference between these two groups, levels of general psychopathology, impulsivity scores and mood disorder questionnaire scores were significantly higher in patients with comorbid impulse control disorder. Conclusion: The results of this study show that one third of depressive patients who presented to our outpatient clinics within a one-year period were diagnosed with at least one lifetime comorbid impulse control disorder according to DSM-IV. Since impulse control disorders are frequently seen, in order to avoid eventual complications in the course of comorbid depression and establish proper treatment plans, close evaluation and recognition of impulse control disorders are necessary. (Archives of Neuropsychiatry 2011; 48: 22-30)