The Weekly Mind Reader: Metformin Prevents Antipsychotic-induced Weight Gain

When patients resist or stop taking antipsychotics, one of the most common reasons they cite is weight gain. While the newer generation of medications may lead to a lesser weight gain on the order of 7-10 pounds, drugs like clozapine and olanzapine have been associated with a more than seven percent increase in users’ body weight.  A new The Journal For Clinical Psychiatry study indicates the diabetes medication metformin could offer a solution. 

Testing Parameters

To test the efficacy of metformin for managing antipsychotic-induced weight gain (AIWG) in children and adolescents on second-generation antipsychotics, Texas researchers gathered records from over 800  children and adolescents aged 6 to 17 who began treatment with second-generation antipsychotics (SGAs) over a five-year period. These patients received metformin during their SGA treatment. The primary analysis assessed changes in Body Mass Index (BMI) z scores, both before and after the initiation of metformin. Additionally, the study looked at the influence of the timing of metformin initiation and the pre-existing weight status.

Over a six-month period, metformin users had noticeably less weight gain compared to the non-users. Subjects who took the medication also experienced a slower rise in poundage than those who didn’t. On average, metformin users saw their rate of weight gain decrease each month by an additional 0.053 BMI z score points.

The benefit of metformin was even more pronounced in patients who did not have obesity. Compared to patients with mildly to moderate or severe obesity, patients at a healthy weight on metformin gained weight much more slowly. Though the drug didn’t reverse weight gain trends, it was more effective at slowing them down or even halting if a patient’s BMI was considered “normal” at the onset of metformin treatment. 

However, the timing of therapy didn’t significantly alter the results. Whether metformin was started early or late after beginning SGA treatment, it consistently helped keep gains to a minimum. Looking at a longer period of 12 months, the positive effects of metformin remained stable. This suggests that metformin can be a reliable long-term strategy for weight management in younger patients on antipsychotic medication, making it a promising approach to managing one of the key side effects of these medications.

Read the full report in The Journal of Clinical Psychiatry. 

IN OTHER PSYCHIATRY AND NEUROLOGY NEWS

• New TX-YDSRN research evaluated psychometrics to provide crosswalks between three self-report measures of depressive symptomatology in youth in psychiatric care settings.
• In a Letter to the Editor, British researchers highlighted the adverse effects of antipsychotics on sexual function. 
• A new case report on the addictive nature of online fantasy gaming finds it has a lot in common with gambling addiction. 
• Family involvement following a patient’s suicide attempt is important for suicide prevention and safety planning.
• In this excellent personal essay, Russell Ledet, MD explains why encouragement from the entire medical community, from nurses to janitors, has been so meaningful to him as a young medical resident of color. 

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