Bipolar disorder and criminal offending: a data linkage study
Purpose: The current study explored criminal offending among people diagnosed with bipolar disorder with and without comorbid substance use and compared this with a community sample with no history of bipolar disorder. Methods: A case-linkage design was used to compare patterns of officially recorded criminal offending between 1,076 people with bipolar disorder drawn from a state-wide psychiatric case register with a community comparison group. Results: Those with bipolar disorder were significantly more likely than community members to be charged with, convicted of, and be found guilty of, violent, non-violent and intermediate level criminal offences. Those with a comorbid substance use disorder were two times more likely than those without a substance use disorder to offend; both groups had a significantly higher chance of offending than the community sample. Females with bipolar disorder were significantly more likely to have been convicted of violent offences, irrespective of substance use. Significant interactions were found between bipolar disorder and substance use for males and females with respect to violent offending and for males with respect to non-violent offending. Conclusions: There is a statistically significant association between bipolar disorder and the likelihood of having a criminal history. Co-occurring substance use differentially impacts on the likelihood of criminal offending for males and females.