Persons with autism spectrum disorder (ASD) may have other psychiatric conditions that warrant treatment. Symptoms may not be easy to discern from rigidity or irritability that are sometimes considered to be constituent parts of ASD. Pathophysiology that involves hyperexcitable neurons and anomalous connectivity may provide justification for using psychopharmacologic agents, although nonmedical strategies may also be effective. Hyperactivity, irritability, and tantrums with or without aggression may be rational targets for psychopharmacological intervention. The best-studied drug class to date has been the second-generation antipsychotics targeting irritability.