The largest study ever done of long-term antipsychotic therapy for schizophrenia—with an average follow-up of more than 14 years—confirmed that patients are safer with medication than without it.
The study by researchers at Karolinska Institutet in Sweden and colleagues in Germany, the United States, and Finland found that mortality was sharply higher during periods when patients were not using medication than when they were.
People with schizophrenia have an average life expectancy 10 to 20 years below the norm, and there has long been concern that one cause is the long-term use of antipsychotic drugs. Earlier meta-analyses, however, indicated that the mortality rate for people with schizophrenia on antipsychotic medication was 30% to 50% lower than those who have received placebo. Still, most studies have been shorter than six months, which does not reflect the reality of often-lifelong treatment. The new research substantiates previous results and demonstrates that antipsychotic drugs are not associated with increased risk of co-morbid complications, such as cardiovascular disease.
"It's difficult to make comparisons between people on permanent medication and those who aren't, as these groups differ in many ways," says Heidi Taipale, assistant professor at the Department of Clinical Neuroscience at Karolinska Institutet. "One common method of dealing with this has been to try to take account of such differences when making comparisons. However, we chose another method, in which each person was their own control, making it possible for us to make individual comparisons of hospitalization during periods of antipsychotic medication and periods of no treatment."
By accessing various Finnish registries, the researchers monitored 62,000 Finns who received a schizophrenia diagnosis between 1972 and 2014, resulting in an average follow-up period of more than 14 years. They found that the likelihood of being hospitalized for a somatic disease was just as high during periods when the patients were on antipsychotic drugs as when they were not. The differences in mortality, however, were noticeable. The cumulative mortality rates in the follow-up period at times of medication and nonmedication were 26% and 46%, respectively.
The researchers believe there is overwhelming support for continual antipsychotic treatment for schizophrenia being safer than no medication. At the same time, treatment brings the risk of adverse reactions, such as an increase in weight, which can raise the risk of cardiovascular disease. The finding that treatment with antipsychotic drugs does not increase the likelihood of hospitalization for cardiovascular disease may be attributable, the researchers argue, to the fact that the drugs can also have an antihypertensive effect and can reduce anxiety and the risk of substance abuse. Antipsychotic treatment may also help patients adopt a healthier lifestyle and seek care when needed.
The study was published in World Psychiatry.
Source: Karolinska Institutet, January 10, 2020