The patient has coarse parkinsonism accompanied by full or partial treatment resistance. This condition is often the result of unnecessary dosage escalation in poorly responding patients, brought about by a desire to contain recurrent violent behavior, shorten length of hospital stay, or deal with "breakthrough" exacerbations which the clinician (probably incorrectly¹) attributes to inadequate dose. When the behavior improves, the dose may not be lowered, even if the previous increase produced only temporary, sedative benefit at best. The patient may have had the potential, given adequate time or a less stimulating envronment, to make a reasonable response to the lower dose, but on this higher dose may have gone beyond the optimal dose in terms of response/side effects ratio. The patient may now be in a toxic state, or "over the window" with inhibited response from an excessive dose. (2,3,4)
Another cause of this situation is using standard doses of neuroleptics in patients who are slow metabolizers or pharmacodynamically highly susceptible to neuroleptic side effects. Asian individuals are well-known to frequently have these differences, and they should be generally treated with lower doses that Caucasians unless they do not develop these side effects. (5)
The treatment strategy will first call for an effort to lower the dose. (6)
¹Subsyndromal Depressive Syndrome, or Depression NOS in DSM-4, is a major public health problem that produces significant functional impairment. See Judd LL. Socioeconomic burden of subsyndromal depressive syndrome and major depression in a sample of the general population. Am J Psychiatry 1996;153:1411-1417.
²Mason BJ, Kocsis JH, Ritvo EC, Cutler RB. A double-blind, placebo-controlled trial of desipramine for primary alcohol dependency stratified in the presence or absence of major depression. JAMA March 13, 1996;275(10):761-767.
³Gelenberg A. Biological Therapies in Psychiatry Newsletter 1996;19(7):25-26.