The finding is of particular concern because individuals with severe mental illness are more likely to die younger than people without severe psychiatric disorders.
"These patients tend to pass away much younger, with estimates ranging from 12 to 25 years earlier than individuals in the general population," said first author Sarah M. Hartz, MD, PhD, assistant professor of psychiatry at Washington University. "They don't die from drug overdoses or commit suicide the kinds of things you might suspect in severe psychiatric illness. They die from heart disease and cancer, problems caused by chronic alcohol and tobacco use."
The study analyzed smoking, drinking and drug use in nearly 20,000 people. That included 9,142 psychiatric patients diagnosed with schizophrenia, bipolar disorder or schizoaffective disorder an illness characterized by psychotic symptoms such as hallucinations and delusions, and mood disorders such as depression.
The investigators also assessed nicotine use, heavy drinking, heavy marijuana use and recreational drug use in more than 10,000 healthy people without mental illness.