Psychopathological and neuropsychological symptoms in patients with subclinical and remitted hyperthyroidism.

To investigate relationships between hyperthyroidism and behavior, 45 formerly hyperthyroid patients (now euthyroid) and 51 control subjects were investigated by (a) a semi-structured psychiatric examination, (b) self-rating scales to assess mood states and personality, and (c) neuropsychological tests. Patients with "subclinical" or "remitted" hyperthyroidism showed more abnormalities than the controls in all dimensions investigated. Forty-three percent of patients (10% of controls) complained of "seriously reduced" well-being with feelings of fear, hostility, and inability to concentrate. While a fearful-agitated syndrome dominated in the initial phase of the illness, a mainly depressive syndrome was characteristic after a longer period of remission. More than 25% of the patients (2% of controls) showed "markedly impaired" neuropsychological functioning. Patients with a relapse within 2.5 years exhibited the most abnormal results. Even after a longer period of hormonal remission, there was no complete psychopathological and neuropsychological normalization. A thorough follow-up of hyperthyroid patients is recommended.