What do we know about the interplay between mental illness and violence? Contrary to the claims made by many mental health professionals, people with mental illness do appear to have an increased risk for violence
compared to the general population, although that risk varies depending on how broad or narrow mental illness is defined. Additionally, the risk is much smaller than generally conceived of by the lay public. Most importantly, the risk appears strongly tied to the use of drugs and alcohol, the rates of which can be exceedingly high
among some populations with mental illness.
We also know that medication compliance among those with severe mental illness, including schizophrenia and bipolar disorder, tends to be poor. This if often attributed to a lack of insight
by those with these severe illnesses that they indeed have a medical illness that requires consistent treatment. But another reason less often stated in official publications but discussed professionally is the fact that many psychiatric medications have bad side-effects, including significant weight gain, sedation, and gastrointestinal discomfort to name but a few.
Despite these limitations, medication remains the primary treatment for most forms of severe mental illness. In fact, they are vital. Compared to no treatment at all, consistent use of medication in the treatment of psychotic disorders, such as schizophrenia, is linked with a range of better outcomes, including symptom severity, substance abuse, homelessness, reduced hospitalizations and many others
Now comes a new study
showing that consistent use of medication is associated with a reduction of violence among those with schizophrenia and bipolar disorder. Let's just let the findings speak for themselves:
In 2006--09, 40 937 men in Sweden were prescribed antipsychotics or mood stabilisers, of whom 2657 (6·5%) were convicted of a violent crime during the study period. In the same period, 41 710 women were prescribed these drugs, of whom 604 (1·4 %) had convictions for violent crime. Compared with periods when participants were not on medication, violent crime fell by 45% in patients receiving antipsychotics (hazard ratio [HR] 0·55, 95% CI 0·47--0·64) and by 24% in patients prescribed mood stabilisers (0·76, 0·62--0·93). However, we identified potentially important differences by diagnosis--mood stabilisers were associated with a reduced rate of violent crime only in patients with bipolar disorder. The rate of violence reduction for antipsychotics remained between 22% and 29% in sensitivity analyses that used different outcomes (any crime, drug-related crime, less severe crime, and violent arrest), and was stronger in patients who were prescribed higher drug doses than in those prescribed low doses. Notable reductions in violent crime were also recorded for depot medication (HR adjusted for concomitant oral medications 0·60, 95% CI 0·39--0·92).