Atypical antipsychotic medication improves aggression, but not self-injurious behaviour, in adults with intellectual disabilities.
Newer antipsychotics trim aggression a little, leave self-injury flat, and add pounds—so measure weight and keep behavior plans active.
01Research in Context
What this study did
Doctors switched adults with intellectual disability from older antipsychotics to newer ones. They tracked aggression and self-injury for one year. The study had no control group.
What they found
Aggressive acts dropped, but self-injury stayed the same. Every adult gained weight. The average gain was 6.6 pounds.
How this fits with other research
Mueller et al. (2000) saw olanzapine cut stereotypic self-injury in half. The new study saw no SIB change. The difference: the 2000 group was picked for chronic SIB, this group was not.
Farrant et al. (1998) reported risperidone helped both aggression and SIB. The new split result shows earlier case series may have overstated SIB benefit.
Laermans et al. (2025) later showed many adults can taper off these drugs and still do better. Their tapering data now question the need for lifelong use.
Lawer et al. (2009) ran a placebo trial and found antipsychotics cost more without clear extra gain. The small aggression drop here matches their weak clinical signal.
Why it matters
You may see smaller aggression drops than families hope for. Self-injury needs behavior plans, not pills. Start a weight log at baseline and check the scale monthly. Pair any med change with solid behavior supports.
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02At a glance
03Original abstract
OBJECTIVE: Atypical antipsychotic medications have largely supplanted their typical counterparts, both for psychosis and for the treatment of aggression and/or self-injurious behaviour (SIB), in persons with intellectual disabilities (ID). However, with the exception of risperidone, little systematic research supports their use in such persons. METHOD: A retrospective review of 31 adult residents of a state developmental centre, who were treated for aggression and/or SIB with atypical antipsychotics. Average monthly counts of aggression and SIB for 1 year of treatment with typical antipsychotics, were compared with monthly averages for the next 12 months of treatment with atypical antipsychotics. RESULTS: Twenty-seven of 31 subjects (87%) completed a full year of atypical antipsychotic treatment. Subjects ranged in age from 24 to 54 years (mean = 39); 18/31 (58%) had profound ID. Twelve of 26 (46%) had typical antipsychotics discontinued within the year of atypical treatment; another 7/26 (27%) had their typical antipsychotic dose decreased. Twenty-three of 31 trials involved risperidone; 7/31 olanzapine; 1/31 quetiapine. Subjects gained an average of 6.6 pounds during the year of atypical treatment, but no significant changes in glucose or cholesterol were found. Subjects with aggression alone (N = 14) had significant decreases in the number of aggressive acts per month during the year of atypical treatment (P = 0.03); those with both aggression and self-injury (N = 12), or those with self-injury alone (N = 5) had no significant improvement. CONCLUSION: The findings suggest that atypical antipsychotics can be successfully substituted for typical agents in individuals with ID and decrease the frequency of aggression over one year of treatment. The weight gain seen in our sample reinforces the necessity of regular monitoring of weight and metabolic changes in persons with ID treated with atypical antipsychotics.
Journal of intellectual disability research : JIDR, 2008 · doi:10.1111/j.1365-2788.2007.00981.x