Antipsychotic treatment linked to rapid metabolic changes in first 90 days

A study led by University College London (UCL) and published in The Lancet Psychiatry has identified the first 90 days of antipsychotic treatment as a critical period for rapid metabolic changes. Researchers analyzed NHS records for nearly 97,000 adults in England aged 18 to 59 who began taking olanzapine, quetiapine, risperidone, or aripiprazole.

During this initial three-month window, glycated haemoglobin (HbA1c)—a measure of average blood sugar—rose approximately 14 times faster than in the pre-treatment period, while weight increased about nine times faster. Olanzapine was associated with the most significant shifts, with HbA1c rising roughly 50 times faster and weight increasing 10 times faster than baseline levels.

The research highlights that weight gain and blood sugar changes do not always occur simultaneously, meaning monitoring weight alone may be insufficient to track metabolic health. The study also noted that women experienced steeper early increases in HbA1c than men, and individuals with prediabetes were at a higher risk of developing type 2 diabetes within two years of starting treatment.