Psychiatric aspects of methylmercury poisoning.

Forty-three patients with methylmercury poisoning were studied; 74·4% showed some degree of depression. Their blood levels of mercury were higher than the average values for the whole group, and considerably higher than the blood levels of the non-depressed patients. Irritability was observed in 44·2% of the patients, all except one of the 19 being under 30 years of age. There was general improvement in the mental states of the patients who were hospitalized. Mercury binding compounds did not seem to have a significant effect in enhancing recovery from the depressive state. The possibility of there being two distinct syndromes, due to organic and inorganic mercury poisoning, is discussed.