Antipsychotic treatments for schizophrenia may be a risk factor for hypothyroidism according to a recent study in Psychiatry Research. Patients with schizophrenia had higher rates of hypothyroidism after starting treatment compared to before treatment.
The retrospective study included 1252 patients aged 18 to 24 and diagnosed with schizophrenia. The control group consisted of 3576 people without schizophrenia. Data came from Clalit Health Services in Israel, which serves more than half the country’s population. The researchers evaluated demographic data, height, weight, laboratory results, and medications issued per year.
Before schizophrenia diagnosis, the rate of hypothyroidism was essentially the same between groups (29/1252, 2.3% and 90/3756, 2.4%, P=.872). After diagnosis, the rate of hypothyroidism was higher in the schizophrenia-diagnosed group compared to the control (121/1252, 9.7% vs 190/3756, 5.1%, P<.001).
Metabolic syndrome is one possible reason for the higher rate of hypothyroidism in individuals diagnosed with schizophrenia. Previous studies show a higher rate of metabolic syndrome in diagnosed schizophrenia patients.
Limitations include a retrospective register-based design and the fact that thyroid-stimulating hormone values were missing from some participants. Consequently, the actual rate of hypothyroidism might be even higher than reported in the present study.
Melamed SB, Farfel A, Gur S, et al. Thyroid function assessment before and after diagnosis of schizophrenia: A community-based study. Psychiatry Res. 2020 Nov 29;293:113356. doi: 10.1016/j.psychres.2020.113356.