Purpose: The systematic review summarised the research investigating potential risk factors for impulsive behaviours in forensic populations. The empirical study examined the predictive utility of clinician rated, self-report and behavioural measures of impulsivity in detecting violence and antisocial behaviour in forensic mental health inpatient settings. Method: The review is comprised of 9 studies identified through electronic database searches using a structured search strategy and predetermined inclusion criteria. The empirical study employed a cross-sectional design using retrospective and prospective statistical analysis. Forty-three participants were recruited from secure forensic mental health inpatient settings across Scotland and data collected from clinician rated, self-report and behavioural measures of impulsivity. Results: The review found original evidence to suggest that traumatic brain injury, substance and alcohol misuse, trauma and sleep as possible predictors of impulsive behaviour in forensic populations. The empirical study found a relatively consistent relationship between impulsive behaviour and violent or antisocial behaviour in a sample of forensic mental health inpatients. Conclusions: The systematic review identified a limited number of risk factors thought to influence impulsive behaviour in forensic populations. The review highlights the need for future research with improved methodological design to further explore contributory factors for increased levels of impulsivity. Findings from the empirical study reveal clinician rating of impulsive behaviour to be the most sensitive in predicting future incidents of violent and antisocial behaviour, which may be supplemented by the addition of a self-report measure.

Assessment research of forensic populations has largely dealt with finding differences within criminal types. Fourteen of the studies reviewed found no significant differences between types of criminals on test performance. Two of these fourteen found no differences between criminals and noncriminals . The Criminal Thinking Model developed by Yochelson and Samenow proposed a continuum of criminality with every person falling somewhere between the two poles of responsibility and irresponsibility. Perhaps one reason previous research failed to discriminate differences was because they had failed to first establish if criminals differed from noncriminals.