Tryptophan malabsorption in dementia. Improvement in certain cases after tryptophan therapy as indicated by mental behaviour and blood analysis.

Twenty-four senile dementia patients in the age range 65-85 years were subjected to a new sensitive tryptophan loading test: Dopa-Tryptophan loading ("Dop-Try loading") in order to determine whether Try malabsorption occurs in senile dementia and if so how frequent this is. For comparison the same loading test was performed on 23 subjects in the same age grouping but with normal metal function. The differences in Try absorption were statistically analyzed and this revealed that absorption was less effective in the senile dementia group. Four patients with Try malabsorption were treated with 3 G 1-Try + 50 Mg dl-5-hydroxytryptophan (5-HTP) per day orally for 20-30 days and four patients with normal absorption were treated in the same way. The Dop-Try loading test was repeated after this treatment. Two patients showed improved absorption and coincident mental improvement, while one showed decreased absorption and mental deterioration. One died during the course of the treatment. None of the four patients with normal absorption showed mental improvement after the treatment. This pilot study suggests that increase in Try absorption following the Try treatment is a necessary condition for improvement in the mental state. The study is being continued with larger numbers of patients.