Thyroid indices in panic disorder.

Eighty-two patients suffering from panic attacks with or without phobias were examined for evidence of thyroid disease. None of the patients had abnormal total T4 or T3 resin uptake measurements, regardless of whether they were nonmedicated or treated with one of three antipanic drugs: alprazolam, phenelzine, or imipramine. A higher than expected incidence of undetectable TSH levels (22% overall) appeared in all groups. The clinical relevance of this finding is currently uncertain.