|Substance Abuse dramatically increases the|
chances of a person with Schizophrenia
acting out in a violent manner.
People rattle off all kinds of statistics about the risk of violence associated with mental illness. People with mental illness are more likely to commit violent crime than "normal people..." People with mental illness are more likely to be victims than perpetrators... People with Schizophrenia are less likely to assault someone than a non-mentally ill individual... But, are any of these statements true? Where did these assertions come from? What type of bias does the individual asserting these claims have?
In order to answer some of these questions, researchers in the UK looked at the risk of committing a violent crime and how it related to Schizophrenia. In a 2009 study, they looked at thousands of individuals diagnosed with Schizophrenia and compared their arrest rates to thousands of individuals in the population at large.
These researchers discovered that 13.2% of individuals with Schizophrenia had a history of at least one violent crime. They compared this rate to the 5.3% of individuals in the general population with at least one violent crime and concluded that Schizophrenia may indeed be a risk factor for violence.
But, the researchers did not stop there. They continued to parse the data and discovered something interesting:
A vast majority of the 13.2 % of individuals with Schizophrenia who had a history of violence also had a substance abuse problem. In fact, 27% of the Schizophrenia & Substance Abuse group had a history of violent crime. Over 1 in 4 people with Schizophrenia and a substance abuse problem had committed at least one violent crime.
When this group of dually diagnosed individuals was taken out of the Schizophrenia-only group, the percentage of individuals with Schizophrenia who had committed a violent crime dropped to 8.5%, much closer to the violent crime rate in the general population.
These are strong results that make it clear that substance abuse and Schizophrenia do not mix well. If someone has Schizophrenia and any type of substance abuse issue, he/she is highly likely to commit some sort of violent act--it may not be as dramatic as a killing spree, but the individual is probably more likely to be angry, combative and unpredictable. But, an individual with Schizophrenia and no substance abuse issues is probably no more dangerous than the average person.
Thanks for reading-- Max Wachtel, Ph.D.
Fazel, S.Långström, N.Hjern, A.Grann, M.