Psychosis encompasses a broad behavioral spectrum, including impaired content and coherence of thought, reduced connection to reality, hallucinations, delusions, disorganized speech and behavior, and extremes of affect and motivation. The diagnosis of psychosis can be difficult, as many patients willfully hide their signs and symptoms such as delusional beliefs, and others are “quietly psychotic,” showing only quirky mannerisms. Psychotic symptoms may be categorized as positive and negative.
- Positive symptoms include tangential, incoherent speech and thought, hallucinations, delusions, and aggression, as well as exaggerated, bizarre, or disorganized behaviors.
- Negative symptoms include poverty of speech or speech content, flattened affect, social withdrawal, anhedonia,apathy and impaired attention and self-monitoring.
Interictal psychosis occurs in approximately 7% of all patients with epilepsy, including patients with both partial and generalized epilepsy syndromes (1–4). Chronic epilepsy probably contributes to the development of psychosis in some patients. Risk factors for interictal psychosis include early age at onset of epilepsy, female sex, severe epilepsy, left-sided temporal lobe focus, and a structural brain lesion (2).
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.
- Slater E, Beard AW. The schizophrenia-like psychoses of epilepsy. Br J Psychiatry 1963;109:95–150.
- Whitman S, Hermann BP, Gordon A. Psychopathology in epilepsy: how great is the risk? Biol Psychiatry 1984;19:213–6.
- Trimble MR. The psychoses of epilepsy. New York: Raven Press, 1991.
- Mendez MF, Grau R, Doss RC, Taylor JL. Schizophrenia in epilepsy: seizure and psychosis variables. Neurology 1993;43:1073–7.
Reproduced and adapted with permission from Orrin Devinsky, M.D. and Epilepsia.