“The perception that mental illness and psychiatric
symptomatology uniformly lead to aggression and violence is a
major source of stigma for the severely mentally ill.”
(Zhuo, Bradizza and Maisto, 2014)
PsychCentral reports that a study conducted under the auspices of the University of Buffalo found that substance abuse is a stronger predictor of violence than severe mental illness and that treating the substance abuse disorders in dually diagnosed patients illness can reduce their risk of future violence. The study appears in the current issue of the Journal of Substance Abuse Treatment (47 (2014) 353–361).
The investigators, Yue Zhuo, Clara M. Bradizza, and Stephen A. Maisto, identified 278 patients of a publicly-funded community mental health center in Buffalo, New York who were diagnosed with both a severe mental illness (a schizophrenia-spectrum or bipolar disorder) and a substance use disorder. These subjects not only met criteria for current alcohol dependence (97%) or alcohol abuse (3%) but also had high rates of comorbid drug use disorders. 86% met DSM-IV criteria for at least one drug use disorder (76% cocaine abuse/dependence, 46% marijuana, 23% opiates, 16% sedatives/hypnotics and 9% amphetamines). The research team followed these subjects over a 6-month period following their admission to an outpatient dual diagnosis treatment program. Then they analyzed the data they obtained to study the association between subjects’ attendance at treatment and subsequent displays of aggression.
For the purposes of this study, “treatment utilization was defined as the number of days during the first 4 months following treatment enrollment that participants either received outpatient treatment and/or were in attendance at a self-help group meeting (e.g., Alcoholic Anonymous, Narcotics Anonymous, or Double Trouble in Recovery).” Aggression was assessed by querying subjects monthly about how often the following events happened as a result of their drinking or drug use: (a) arguments with family and friends; (b) physical fights when under the influence; (c) arrests due to behavior when they were drunk or high; (d) infliction of injury to someone else; and (e) damage to property or breaking things. These questions, along with assessments of drug and alcohol use and treatment utilization were administered for the previous 12 months at baseline and monthly after the initiation of the study.
Analyses revealed that dual diagnosis treatment was associated with lower levels of subsequent aggression. However, a thorough examination of the data held some surprises for the investigators.
They observed that, “In our model, severity of psychiatric symptoms did not predict severity of later aggression; instead, aggression was more closely associated with severity of substance use ” and thorough analyses of data indicated that “greater treatment involvement was associated with reduced substance use, which was associated with lower levels of aggression”. The research team concluded that “substance use was found to mediate the relationship between dual diagnosis treatment and aggression” and that “targeting substance use reduction in treatment may have the additional benefit of reducing the risk of later aggression among dual diagnosis patients.”
Very interestingly, the authors of this study also found that while psychiatric symptoms were not directly associated with aggression, individuals with worse initial psychiatric symptoms received less treatment, and that “attending less treatment was associated with greater aggression both directly and via greater substance use”.