MC4R methylation and antipsychotic-related metabolic changes in early psychosis: findings from two prospective cohorts

Metabolic side effects represent a major long-term concern in antipsychotic (AP)-treated early psychosis. We evaluated the weight gain and changes in related metabolic parameters in patients followed up for 12 months. We also explored DNA methylation of four genes associated with weight gain (ADRA2A, INSIG2, LEP, MC4R). We included patients aged 15-64 years followed in the Ribeirão Preto Early Intervention in Psychosis Program from two different cohorts (Clinical sample, n = 147; Epigenetic sample, n = 59). DNA methylation was analysed by pyrosequencing only at baseline, after several weeks of AP exposure. In both cohorts, 40% of patients initially received second-generation antipsychotics (SGAs), increasing to over 70% after one year. Clinical sample: At follow-up, patients exhibited significant increases in body mass index (p < 0.001), triglycerides (p < 0.001), HDL-c (p = 0.001) and LDL-c (p < 0.001). Patients predominantly on SGAs during the 12 months had almost three times higher chance of weight gain than those using haloperidol. Other factors associated with weight gain included non-white skin colour (OR = 2.6), fewer years of schooling (OR = 2.5) and a weight gain of at least 7% at three months (OR = 3.1). Epigenetic sample: Patients receiving SGA treatment (median = 23.4 weeks) at baseline showed hypermethylation within the MC4R promoter region in relation to patients using haloperidol (median = 18.6 weeks). No changes in the baseline methylation of other genes related to weight gain or AP drugs were observed longitudinally. MC4R promoter hypermethylation in SGA-treated patients suggests drug-induced metabolic alterations and a potential role of MC4R as a biomarker for predicting AP-related metabolic risk.