Very good question. No one really knows the answer to that one. But it is likely to be a generalised neurotransmitter effect. though some would argue that it is dopamine specific. Nothing is a 'magic bullet' in psychiatric drugs. Also worth noting some people don't get sedated on them (rare though). The future is individualised genetically-driven treatments matched to you personally. Of course sometimes the sedation is a useful effect if agitation accompanies symptoms. Olanzapine is usually much more sedating than risperidone and is often chosen exactly for that reason. Dr R Fry, Integrative Psychiatrist.