EXTRAPYRAMIDAL SYMPTOMS ASSOCIATED WITH CYCLIC ANTIDEPRESSANT TREATMENT - A REVIEW OF THE LITERATURE AND CONSOLIDATING HYPOTHESES

Extrapyramidal symptoms (EPS) including parkinsonism, akathisia, dysto nia, and tardive dyskinesia have commonly been associated with acute o r chronic administration of neuroleptic drugs. A review of the medical literature reveals a substantial number of cases with similar clinica l characteristics associated with the tricyclic antidepressants, monoa mine oxidase inhibitors, and selective serotonin reuptake inhibitors ( SSRIs). Although the data are not sufficient to make definitive pharma coepidemiologic conclusions, the available number of case reports sugg ests the SSRIs may be more common offenders in producing these adverse drug effects. The exact mechanism is elusive but likely involves comp lex interactions of dopamine, serotonin, and norepinephrine between co rtical structures and the basal ganglia. The final common pathway for production of EPS seems to be indirect modulation of dopaminergic func tion. Predictors of patients at risk for antidepressant-induced EPS ar e not established, but a greater awareness of the potential for these drug side effects to occur may increase their recognition and decrease antidepressant-induced morbidity.