To answer the question if it is possible for specific psychiatric illnesses to influence the thyroxine-concentration, a group of 376 patients admitted to a psychiatric hospital was studied retrospectively.
13.5% had an elevated thyroxine-concentration and only 0.6% had a low concentration.
Of the group of 145 men, 22.8% was found to have an elevated thyroxine-concentration. In the group of 196 women we found 6.6% to be elevated. A low thyroxine was found in only 0.5% of the women and 0.7% of the men.
In the group with an elevated thyroxine the psychiatric diagnoses of schizophrenia and psychotic disorders NOS are more common (19.6% and 17.4% respectively) than in the group with a normal thyroxine (4.4% and 6.5% respectively).