Researchers at Karolinska Institutet in Sweden and their colleagues in Germany, the U.S. and Finland have studied the safety of very long-term antipsychotic therapy for schizophrenia. According to the study, which is published in the scientific journal World Psychiatry, mortality was higher during periods when patients were not on medication than when they were.
People with schizophrenia have an average life expectancy ten to twenty years below the norm, and there has long been concern that one of the causes is the long-term use of antipsychotic drugs. Earlier compilations (meta-analyses) of results from randomized studies, however, indicated that the mortality rate for people with schizophrenia on antipsychotic medication was 30 to 50 percent lower than those who have received placebo.
However, most of the studies done have been shorter than six months, which does not reflect the reality of treatment often being life-long. Researchers from Karolinska Institutet and their international colleagues have now done a long-term follow-up, substantiating previous results and demonstrating that antipsychotic drugs are not associated with increased risk of co-morbid complications, such as cardiovascular disease. The study is the largest conducted in the field to date.
"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."
The researchers monitored just over 62,000 Finns who had received a schizophrenia diagnosis at some time between 1972 and 2014. This they did by accessing various Finnish registries up until 2015, giving an average follow-up period of over 14 years. They found that the likelihood of being hospitalized for a somatic disease was just as high during the periods when the patients were on antipsychotic drugs as when they were not. The differences in mortality, however, were noticeable. The cumulative mortality rate in the follow-up period at periods of medication and non-medication was 26 and 46 percent respectively.
The researchers believe that there is overwhelming support for continual antipsychotic treatment for schizophrenia being a safer option 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, argue the researchers, 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 make them more likely to seek care when needed.
"Antipsychotics get something of a bad press, which can make it difficult to reach out to the patient group with information on how important they are," says Jari Tiihonen, professor of psychiatry at the Department of Clinical Neuroscience, Karolinska Institutet. "We know from previous studies that only half of those who have been discharged from hospital after their first psychotic episode with a schizophrenia diagnosis take antipsychotic drugs. Besides, there are many people with schizophrenia who are on long-term benzodiazepine medication, which is in breach of existing guidelines and is associated with increased mortality risk. Building trust and understanding towards the efficacy and safety of antipsychotic drugs is important, and we hope that this study can contribute to this end."
More information: 20-year follow-up study of physical morbidity and mortality in relationship to antipsychotic treatment in a nationwide cohort of 62,250 patients with schizophrenia (FIN20), World Psychiatry, DOI: 10.1002/wps.20699.
Provided by Karolinska Institutet