A single fasting level of serum prolactin was measured in each of sixty control subjects and eighty-three psychiatric patients of both sexes who had been on neuroleptic therapy for 2-4 weeks (acute treatment) or at least 5 years (chronic treatment) and who were aged either 17-45 or 48-85 years. All groups of patients had significantly higher mean prolactin levels than controls. Gender, age group of women, and exposure to acute or chronic treatment were significant variables determining the magnitude of neuroleptic-induced elevation of prolactin. In some of the groups, dose, duration of chronic therapy, and concomitant administration of anticholinergic drugs also influenced prolactin levels. Whereas all acutely treated women had prolactin values above the control range, one out of twelve (8-3%) of the women aged 17-45 years and six out of fourteen (42-9%) of the women aged 48-85 years who were under chronic treatment had normal values. Normal prolactin levels were also found in five out of sixteen (31-2%) of the acutely treated and nine out of twenty-four (37-5%) of the chronically treated men aged 17-85 years.

In a group of 12 hospitalized psychogeriatric patients, the fractional triiodothyronine (T3) turnover rate was significantly higher than in healthy control subjects of the same age, whereas the thyroxine (T4) turnover rate and other aspects of pituitary-thyroid function were virtually similar in both groups. Despite the presence of manifestations of sympathetic overactivity or hypermetabolism, the patients did not have true hyperthyroidism, as verified by the laboratory findings and the results of antithyroid treatment. The increases T3 turnover in aged hospitalized patients with brain disorders may be a compensatory mechanism which develops under these particular circumstances in order to maintain neurohormonal homeostasis. An alternate possibility is that the increased T3 turnover is secondary to hyperkinesis.