Treatment of substance use disorder in forensic psychiatric patients: the role of impulsivity

Substance use appears to have a negative influence on rates of criminal recidivism. The foremost important goal of treatment of forensic psychiatric patients is to protect society from criminal recidivism. Therefore, forensic psychiatric patients need to change maladaptive behaviour, such as substance use. However, lack of problem insight and high levels of impulsivity may impede forensic psychiatric patients from behavioural change. The aim of this study was to investigate whether impulsivity had a moderating effect on the relationship between problem insight into substance use and actual substance use. In order to compare levels of problem insight and impulsivity, 43 forensic psychiatric patients with a substance use disorder (SUD) and a comorbid Axis I and/or II disorder were divided in two groups based on whether or not they used substances in the past six months. Levels of impulsivity were determined by scores on the Barratt Impulsiveness Scale (BIS-11) and the amount of commission errors on the Cued Go/ No Go task. Levels of problem insight into substance use were measured by observations of patients’ behaviour by staff members and were scored independently by the researcher based on examination of daily reports. Participants who did use substances in the past six months appeared to have significantly lower levels of problem insight into their substance use than participants who did not use substances in the past six months. Both groups of participants did not differ in levels of impulsivity, demonstrated by equal total scores of the BIS-11 and the amount of commission errors on the Cued Go/ No Go task. Lower levels of problem insight predicted substance use, but higher levels of impulsivity did not. Hence, no moderating effect of impulsivity on the relationship between problem insight into substance use and actual substance use was found. Possible explanations, such as low to moderate levels of impulsivity within the sample, together with limitations of this study and recommendation for future research are being discussed