Olanzapine and Autism Ranking:

Future Research

Summary of Existing Research

There is some evidence that olanzapine may be beneficial for the treatment of various problems faced by autistic people, including hyperactivity, aggression, and self-injurious behaviours.

There is almost no research evidence to suggest that aripiprazole may be beneficial for the treatment of these behaviours in autistic adults.

There are a few anecdotal reports which suggest that aripiprazole may be beneficial for some autistic children and/or adults.

There is some research evidence of significant side effects of olanzapine in some autistic children and young people. Those side effects may include weight gain, increased appetite and increased drowsiness.

There is also some research which suggests that some antipsychotics, such as olanzapine, can actually increase hyperactivity through akathisia (a movement disorder characterised by a feeling of inner restlessness and a compelling need to be in constant motion).

As always a judgement should be made by the clinical team as to whether the symptoms or behaviours arise from a reaction of the autistic person to stressors in the social or wider environment or whether they related to an underlying psychiatric disorder in the true sense. The treatment approach will differ accordingly with the former less likely to respond to psychotropic drug-based interventions alone.

Recommendations for Future Research

Further, large-scale, randomised, double-blind trials of the effects of olanzapine should be carried out on autistic individuals to determine their effectiveness and safety. 

These studies should investigate issues such as

• The optimal dosage and length of treatment for different autistic individuals including adults
• Comparison of olanzapine with other medications, including with other antipsychotics, such as aripiprazole and risperidone.

Updated

17 Jun 2022

Last Review

01 Feb 2016

Next Review

01 Feb 2019