Olanzapine and Autism Ranking: Mildly Hazardous Limited positive evidence

Anti-psychotic, olanzapine

Olanzapine is an antipsychotic drug used to treat the symptoms of schizophrenia and bipolar disorder.

It is sold under a variety of brand names including Zyprexa, Zolafren and Zydis.

The exact mechanism by which olanzapine works is unknown but some people believe it can be used to change the levels of dopamine and serotonin in the central nervous system.

It is sometimes used to treat problem behaviours in autistic people, including hyperactivity, aggression, and self-injurious behaviours.

Our Opinion

There is some very limited research evidence to suggest that olanzapine may be beneficial for the short term treatment of significant problems faced by autistic people, including hyperactivity, aggression, and self-injurious behaviours.

However there are many potential side effects, especially significant weight gain in all who take it, as well as increased appetite and increased drowsiness in some.  The implications of these side effects are unknown.  For these reasons, it is important to use the lowest effective dose

There is probably more weight gain with olanzapine than with other atypical antipsychotics. It is therefore not the first choice and caution is needed.

Further research should be undertaken into the use of olanzapine and other antipsychotics for the treatment of specific, severe symptoms, as each has a different side effect profile, and so might suit some people better.


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17 Jun 2022
Last Review
01 Feb 2016
Next Review
01 Feb 2019