Insulin Resistance in a Sample of Drug-naive Adolescents at First Episode Psychosis

Conflicting evidence on the risk of type 2 diabetes mellitus in people with schizophrenia prior to antipsychotic treatment has been published in recent years, with limited data focused on adolescent samples. Objective of this study were to compare baseline alterations of glyco‐metabolic parameters between 24 drug naive adolescents in the acute phase of First Episode Psychosis (FEP) and a control group of 21 Clinical High Risk (CHR) for developing psychosis, aged and sex matched. Than we tested eventual changes in glyco‐metabolic parameters of FEP patients after 3–6 months of therapy with risperidone (range 0,5‐3 mg/die). Subjects were recruited among patients consecutively referred over a three years period at the Child Neuropsychiatry Unit, Department of Basic Medical Sciences, Neurosciences and Sense Organs of the University of Bari, Italy. All patients underwent a baseline assessment that involved measurement of anthropometric data and blood levels of glucose, triglycerides, total cholesterol, glycosylated haemoglobin, insulin. Insulin resistance was calculated through the homeostatic model assessment index (HOMA‐IR). FEP patients and CHR controls were compared by using Fisher's exact test for non‐parametric data and Student's t‐distribution for parametric data. P value < 0,05 was considered significant. We found that drug‐naive FEP adolescents were more insulin resistant compared to CHR controls as reflected by statistically significant difference in mean HOMA‐IR score (p=0,038). No significant difference were found in FEP group after treatment with risperidone. Stress system activation could be an explanatory model for insulin resistance in FEP, regardless of the antipsychotic treatment.