Treating Psychosis
Psychosis is treated primarily with dopamine receptor blockers, i.e., the conventional (e.g., chlorpromazine, haloperidol) and atypical (e.g., risperidone, olanzapine, quetiapine) antipsychotic (neuroleptic) drugs. Antipsychotic drugs are also divided into “low-potency” (e.g., chlorpromazine, thioridazine) and “high-potency” (e.g., fluphenazine, haloperidol) groups. Potency is determined mainly by therapeutic dosages and D2 receptor affinities. Among the conventional antipsychotic drugs, high-potency agents are less sedating, hypotensive, and anticholinergic (drugs that block the cholinergic neurotransmitter system) but have more acute motor side effects.
All dopamine receptor blockers are most effective for positive symptoms such as hallucinations and delusions. Atypical antipsychotic drugs are more effective than conventional agents for treating negative symptoms. Although blockade of D2 receptors occurs within hours, antipsychotic action takes days or weeks, suggesting that changes in dopamine receptor affinity or secondary effects are involved. The atypical antipsychotic agents, with the exception of clozapine, are safe for the large majority of patients with epilepsy and uncommonly increase seizure frequency or severity. When weighed against the morbidity and mortality (e.g., suicide) associated with chronic psychosis, use of antipsychotic agents is warranted. For acute and agitated psychosis (e.g., postictal psychosis), the combination of a high-potency antipsychotic agent and a benzodiazepine is often effective. In the long-term management of interictal psychosis, lack of insight, denial of illness, and disorganized thought often lead to noncompliance. Psychosocial intervention is critical, as stress can exacerbate the disorder. Social skills training, vocational training, and independent living skills foster a positive outcome.
