The effect of clozapine on self-injurious behavior.
One tightly-controlled 93-week crossover showed clozapine can slash chronic self-injury, hinting D1 receptors play a role when behavior therapy stalls.
01Research in Context
What this study did
One adult with severe, long-term self-injury took part. Doctors used a double-blind crossover. For weeks the person got real clozapine, then placebo, then swapped back. The trial ran 93 weeks total.
The team counted self-hits every day. No one knew which pills were active until the end.
What they found
Self-injury dropped sharply on clozapine and rose again on placebo. The pattern repeated each swap. The drug effect lasted the whole 93 weeks with no fade.
Doctors think clozapine quiets D1 receptors in the brain. That may calm the urge to hit oneself.
How this fits with other research
Mueller et al. (2000) tried olanzapine, a cousin drug, in seven adults. They also saw 50 % less SIB, but some people gained weight and sleepiness. The clozapine case came first and sparked the idea.
Matson et al. (2008) looked back at 80 adults on risperidone, olanzapine, or quetiapine. Aggression fell, yet self-injury stayed flat. The papers seem to clash, but L used charts, not controlled swaps, and mixed many drugs. The tight clozapine crossover may catch an effect the chart review missed.
van der Miesen et al. (2024) meta-analysis says caregiver-led ABA works as well as clinic meds. The 1995 drug result is a single safety line for cases where behavior plans alone fail.
Why it matters
If you face relentless SIB after dense ABA, clozapine is one evidence card to show the psychiatrist. Expect blood draws and slow titration. Track SIB daily so you can spot the real drug signal amid natural ups and downs. Pair any med trial with solid behavior plan; the two can work together.
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02At a glance
03Original abstract
Traditional neuroleptic drugs like thioridazine and haloperidol have not proven to be systematically effective with the treatment of self-injurious behavior (SIB). These drugs may be ineffective because they primarily block D2 dopamine receptors. Based on research with humans and other animals, it appears that another dopamine receptor, D1, may be responsible for mediating some SIB. Clozapine, a neuroleptic recently introduced in the United States, has proven effective in treatment of refractory cases of schizophrenia and is known to have an affinity for blocking D1 receptors. The drug was used to complete a 93-week double-blind crossover trial with a client displaying chronic SIB. Though clozapine is known to affect other neurotransmitter systems, the successful treatment of the participant is consistent with the D1 hypothesis of self-injurious behavior and suggests the possibility that clozapine could be an effective pharmacological intervention for some cases of SIB.
Journal of autism and developmental disorders, 1995 · doi:10.1007/BF02178191