Effects of fenfluramine on autistic individuals residing in a state developmental center.

Doctors gave 24 autistic teens and adults either fenfluramine or a sugar pill every day for nine months. The pill was meant to cut self-injury, tantrums, and repetitive actions. Staff at the state center recorded behavior twice a week.

Half got the real drug, half got placebo. No one knew who had which until the end.

Fenfluramine did not lower any problem behaviors. Scores on the behavior checklist stayed flat. Side effects showed up: drowsiness, weight loss, and heart flutter.

By month nine the drug group looked the same as the placebo group. The trial was stopped early for safety.

Crossman et al. (2018) repeated the idea 30 years later with riluzole. Same design, same null result: no drop in irritability.

DWaldron et al. (2023) tested pancreatic enzymes in preschoolers. They saw a tiny improvement, but still far below what parents hope for.

Strydom et al. (2020) tried Positive Behaviour Support in adults. Again, no real change over usual care. The pattern is clear: pills and broad programs rarely beat placebo for tough behavior in autism.

You can skip fenfluramine; it is off-market anyway. More important, the study warns us to doubt quick drug fixes for severe behavior. Save your time for functional assessment, reinforcement plans, and crisis-prevention training. When a family asks about new pills, show them this 1987 data plus the newer null trials. Use the evidence to steer the conversation back to behavior analysis and safe care.