Today's regulatory sweep returned one generic olanzapine supplement and nothing else — no new approval, label change or safety communication for psychiatry. That is the usual pattern, and it understates the gap: much of what changes psychiatric prescribing arrives as college guidance and evidence synthesis rather than as regulatory action, and the drug-regulator feeds see none of it.
The document most likely to shape prescribing this period is a network meta-analysis of 95 randomised trials covering 39 pharmacological interventions in 5,898 antipsychotic-treated patients with schizophrenia spectrum disorders. It is evidence synthesis rather than a guideline, but it is the first ranking of this size and it reads as practical guidance. Semaglutide produced the largest weight reduction, 10.98 kg (95% CI -13.33 to -8.62), followed by liraglutide at 5.43 kg, topiramate at 3.95 kg, metformin at 3.86 kg and exenatide at 2.97 kg, all at moderate certainty. Only semaglutide and metformin achieved a clinically meaningful reduction of 5% or more of body weight. Several also improved other metabolic parameters, with no major excess of gastrointestinal adverse effects or dropout.
The practical point is that this is now an answerable question. Antipsychotic-induced weight gain has long been managed by switching antipsychotic, counselling about diet, or accepting it. There are drugs with moderate-certainty evidence, and metformin in particular is cheap and widely available.
- No new psychiatric drug approval or safety action; one generic olanzapine filing
- Semaglutide -10.98 kg, liraglutide -5.43 kg, topiramate -3.95 kg, metformin -3.86 kg
- Only semaglutide and metformin reached 5% or greater weight change
- Evidence synthesis, not a guideline — but the largest ranking yet produced
The statistics, in plain English
Network meta-analysis compares treatments that were never tested against each other by connecting them through shared comparators, which is powerful but weaker than a head-to-head trial. Note how few trials sit behind the top result: semaglutide's estimate rests on three studies against metformin's sixteen. A larger effect from less evidence is not the same as a better-established one, which is why the certainty rating and the number of trials belong beside every figure here.
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