The results of the open-label extension trial on the use of "Metformin for the Treatment of Overweight Induced by Antipsychotic Medication in Young People With Autism" reported by Benjamin Handen and colleagues  is blogging fodder for today. Continuing a research interest from this group (see here), the idea that weight and related side-effects from certain antipsychotic medicines can be managed by a drug readily used to treat type 2 diabetes receives yet more support.
Last time around  researchers showed that under double-blind, placebo controlled conditions, metformin was fairly well-tolerated and did aid in "decreasing weight gain associated with atypical antipsychotic use" in children and young adults diagnosed with an autism spectrum disorder (ASD). This latest publication detailed what happened when everyone - well, 85% of the original cohort - went on metformin in terms of their body mass index (BMI) and "additional body composition and metabolic parameters" for an additional 16 weeks.
Results: well, as would probably be expected, "participants initially taking placebo during the RCT [randomised controlled trial] had reduced BMI z-scores" when metformin was introduced. For those who were already taking metformin during the original trial, prior reductions in BMI were maintained but they "did not experience additional weight loss." I might also add that 'fairly well-tolerated' meant that: "Three participants discontinued treatment due to an adverse event."
These are important findings and add to other preliminary research findings in this area . I know many people (including myself) have some reservations about adding in medicines to treat the side-effects of other medicines (as well as the conditions for prescribing antipsychotics in the first place ), but given what elevated BMI scores can mean to physical health and associated health risks, this is one occasion where intervention might be truly life-saving (with appropriate clinical monitoring assumed). Further studies are indicated.
 Handen BL. et al. A Randomized, Placebo-Controlled Trial of Metformin for the Treatment of Overweight Induced by Antipsychotic Medication in Young People With Autism Spectrum Disorder: Open-Label Extension. Journal of the American Academy of Child & Adolescent Psychiatry. 2017. Aug 19.
 Anagnostou E. et al. Metformin for Treatment of Overweight Induced by Atypical Antipsychotic Medication in Young People With Autism Spectrum Disorder: A Randomized Clinical Trial. JAMA Psychiatry. 2016 Sep 1;73(9):928-37.
 Wink LK. et al. Brief Report: Metformin for Antipsychotic-Induced Weight Gain in Youth with Autism Spectrum Disorder. J Autism Dev Disord. 2017 Jul;47(7):2290-2294.
 Jackel C. et al. Factors Associated with Developmental Behavioral Pediatricians Prescribing Psychotropic Medication to Children with Autism Spectrum Disorder: A Study of Three DBPNet Sites. J Dev Behav Pediatr. 2017 Aug 10.