Substance abusers with mental illness pose high risk of violence
Severe mental illness in isolation does not increase the risk of violent behaviour, however, a combination of mental illness and substance abuse poses a greater risk than substance abuse alone, a study has found. A triple combination of severe mental illness, substance abuse and past violence was associated with a particularly high risk.
A sample of 34,653 American citizens, chosen to be representative of the general population, were interviewed between 2001 and 2003. Recent and lifetime histories of severe mental illness, and risk factors for violent behaviour were identified using a structured interview. A second interview was performed between 2004 and 2005 when participants were asked to report any violent behaviour which had occurred since the baseline interview.
Bivariate analysis showed that participants with any severe mental illness (psychosis, bipolar disorder or major depression) had a significantly increased probability of violent behaviour (OR 2.96). The risk was only increased, however, among those who also had a history of substance abuse and/or dependence. Multivariate analysis confirmed that severe mental illness alone did not predict future violence.
Factors which significantly predicted violent behaviour were:
* historical - past violence, juvenile detention, physical abuse, parental criminal history
* clinical - substance abuse, perceived threats
* dispositional - young, male, low income
* contextual - recent divorce, unemployment, victimisation
Many of these factors, in particular threat perception, were significantly associated with severe mental illness.
Moreover, although severe mental illness alone did not increase the risk of violence, a combination of mental illness and substance abuse posed a greater risk than substance abuse alone. A combination of severe mental illness, substance abuse and past violence was associated with a particularly high risk.
This longitudinal survey of the relationship between serious mental illness and violent behaviour is important for two reasons. First, it challenges the popular and stigmatising belief that mental illness is a leading cause of violence. Second, it provides data which can help us predict when there is a potential risk of violence to us and our staff.
A BMA postal survey found that more than a third of GPs had experienced some form of violence in the workplace during the past year.1
I personally experienced an incident last year, prompting a review of safety within our practice.
We responded to the specific incident by sharing information with other professionals involved with the same patient, asking the patient to sign an acceptable behaviour contract and using an electronic flag to alert receptionists when booking appointments. On a more general level, it highlighted a problem with the configuration of our consulting rooms, safety concerns with regard to extended opening, and the need to try to identify potentially high-risk patients before an incident occurs.
We live in an increasingly violent society. Nearly a third (31%) of GPs in the BMA survey felt violence had increased over the past year whereas only 0.3% felt it had decreased.1 Although it is important not to stigmatise mental illness, we need to be alert to patient attributes and situations where there is the potential for conflict and take steps to minimise the risk.2
Elbogen EB, Johnson SC. The intricate link between violence and mental disorder. Arch Gen Psych 2009; 66:152-61Reviewer
Dr Phillip Bland