High and low dose thiothixene treatment in chronic schizophrenia.

Forty hospitalized treatment-resistant schizophrenics were randomly assigned to high (40 mg.) or low (10 mg.) daily oral doses of thiothixene. Differential effects were predicted on measures of CNS arousal, performance tests, clinical ratings, and perceptual-cognitive training. The high dose showed effects consistent with antipsychotic activity. The low dose showed some changes indicating activating properties. Side effects on high dose included several instances of EPS: akathisia and tremor, and transient CNS stimulation. Low dose produced persistent CNS stimulation: excitement and insomnia. The differentiation of "turbulence" from "activation" is of clinical importance. Methodological problems of sample size, lost performance and EEG data, fixed dose level, and refractory patients probably account for the paucity of statistically significant dose differences.