Cognitive and affective functions in patients with affective disorders treated with lithium. An assessment by questionnaire.

A questionnaire of 19 items was devised to assess subtle changes in affective and cognitive function in patient with effective disorders under long-term lithium therapy. Of 147 patients, 138 (93.9%) answered the questionnaire. The function of the hypothalamic-pituitary-thyroid axis was also analysed by biochemical investigations, and the interrelations between the function of this axis and affective and cognitive functions were studied. The patients under lithium maintenance therapy showed no clearcut changes in effective and cognitive functions. Some statistically significant correlations were found between rising thyrotropin levels and improved affective function. Patients who admitted periods of depression under lithium therapy showed highly significantly greater variance both in free thyroxine index and in thyrotropin levels than patients denying such periods. We may conclude that successful prophylactic lithium therapy against depression is linked to a stabilizing effect on the hypothalamic-pituitary-thyroid axis.