In the largest ever assessment of the correlation between substance use and severe psychiatric illness, Washington University School of Medicine and the University of Southern California have identified that rates of smoking, drinking and drug use are significantly higher among individuals who have psychotic disorders.
The study, published in JAMA Psychiatry, provides some surprising results: among those who use nicotine, drugs and alcohol, the rates of death amongst individuals with severe mental illness are significantly higher than those of individuals without mental illness.
Sarah M. Hartz, MD, PhD, assistant professor of psychiatry at Washington University stated: “These patients tend to pass away much younger, with estimates ranging from 12 to 25 years earlier than individuals in the general population. They don’t die from drug overdoses or suicides — the kinds of things you might expect from patients with severe psychiatric illness. They die from heart disease and cancer, problems caused by chronic alcohol and tobacco use.”
The study analysed smoking, drinking and drug use in nearly 20,000 people. This number included 9,142 psychiatric patients diagnosed with schizophrenia, bipolar disorder or schizoaffective disorder. The study also investigated smoking, heavy drinking and marijuana usage, along with recreational drug use in more than 10,000 people who did not suffer from mental illness.
The research found that 30% of those with severe psychiatric illness often binge drink, (defined as drinking four servings of alcohol at any one time, e.g. 4 glasses of wine or 5 small beers). Also among those with mental illness, 75% were regular smokers, whilst only 33% of people without mental illness smoked regularly.
Although the rates of smoking have declined in the general population, people older than 50 are much more likely than younger people to have been heavy smokers. Similar findings pertained to heavy marijuana users: 50% of people with psychotic disorders used marijuana regularly, compared to 18% of the general population.
Similarly, 50% of the mental illness sufferers engaged in other illicit drug use, while the rate of usage in the general population is approximately 12%.
Hartz noted: “It’s always surprising when I encounter a patient that doesn’t smoke or hasn’t used drugs or had alcohol problems.” She further suggests that the solution lies in being more aggressive with attempts to curb nicotine, alcohol and substance use in patients with severe psychiatric illness, in order to lengthen their lives.
Hartz believes that health professions who treat the mentally ill need to do a better job of trying to get patients to curb their drug and alcohol consumption, suggesting: “We can do better, but we also need to develop new strategies because many interventions to reduce smoking, drinking and drug use that have worked in other patient populations don’t seem to be very effective in these psychiatric patients.”