The relationship between insight and violence in psychosis: implications for forensic practitioners

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Gary Macpherson

Psychosis is a broad term used to describe abnormalities in thinking, perception, emotions, language, behaviour and sense of self. Encouragingly and in line with growing evidence, new nosological classification systems (e.g. the DSM-5) move away from dichotomous classifications of psychosis and position psychosis on a continuum.

For forensic practitioners the propensity for individuals with psychosis to behave violently is a sensitive and much debated subject. Violent behaviour by a minority of individuals who experience psychosis is a poorly understood phenomenon that contributes to the stigma experienced by such persons.

One way in which forensic practitioners assess for risk of violence is via levels of insight or ‘awareness of mental disorder’ demonstrated by persons with psychosis. Insight is included as a risk factor for violence within schedules such as the Historical Clinical Risk Scheme for assessing violence or HCR-20V3 - yet the relationship of insight to violence in persons with psychosis remains unclear even within widely used schedules and there existed no systematic evidence-based review evidencing a relationship between poor insight and violence in people experiencing psychosis.

To establish any relationship between violence and psychosis a systematic review of observational studies investigating insight and violence was completed for published studies spanning almost 40 years between 1980 and 2019 resulting in 5701 articles. A systematic review of the literature revealed partial evidence in support of a relationship between poor insight and violence in psychosis and a number of variables appeared to be associated with the perpetration of violence by individuals with psychosis.

The implications of the systematic review for forensic practitioners supports the widely held view that insight is a multidimensional concept where practitioners should clarify the dimension they aim to measure (e.g. insight into mental disorder, insight into medication compliance, etc.). Practitioners should be careful not to assume poor insight in psychosis is directly related to violence as the review demonstrated the relationship to be complex and dynamic. In terms of risk assessment and management, the review supports the inclusion of poor insight as a risk factor for violence in the HCR-20v3 primarily as the measure implements a multi-dimensional approach to insight which is supported by the current findings.

The relationship between poor insight and violence in psychosis is dynamic, complex and can be influenced by other variables such as psychopathy. This systematic review found partial evidence in support of a relationship between poor insight and violence in psychosis. Our findings suggest that poor clinical insight specifically, is a more robust predictor of violence in patient samples with lower levels of psychopathy than in samples where psychopathy rates are higher. Poor cognitive insight appears to be associated less with violence than poor clinical insight across patient samples. This review also highlighted the multi-dimensionality of insight in those experiencing psychosis and reinforces the difficulties which can be created by a lack of clarity around the concept. Future quality research focusing on insight in psychosis and its relationship to violence, taking account of confounding variables such as medication adherence and psychopathy, is very much required across diverse patient populations.

For the full article please access: ‘The relationship between insight and violence in psychosis: a systematic literature review’ Kerry Johanna Smith, Gary Macpherson, et al Journal of Forensic Psychiatry and Psychology (December 2019)