Parkinsonism from SSRIs

RBD is characterized by a relative absence of the atonia characteristic of REM sleep. This lack of atonia permits the physical acting out of dream mentation, particularly dreams involving confrontation, aggression and violence. RBD is seen most frequently in older men. RBD occurs in both acute and chronic forms. Acute RBD can occur during withdrawal from alcohol or sedative-hypnotics. RBD has also been induced by the tricyclics, SSRIs and venlafaxine. The chronic form of RBD may occur as part of an identifiable underlying neurological disorder, but typically is idiopathic. RBD may also be an initial manifestation of parkinsonism. RBD is very responsive to clonazepam, although this use has not been FDA approved. 

Gerber and Lund (1998) reviewed the literature and located 127 case reports of SSRI-induced abnormal movements. These included akathisia (agitation with hyperactivity), tardive dyskinesia, parkinsonism, dystonia (muscle spasms), bruxism (tooth grinding), and related disorders. They found many additional case reports from the drug manufacturers, including 516 cases of parkinsonism and 76 cases of tardive dyskinesia. The term tardive dyskinesia is usually reserved for cases that are irreversible. 

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