Sodium lactate response and familial risk for panic disorder

OBJECTIVE: The authors used the family study method to test the hypothesis that sodium lactate response defines two subtypes of panic disorder. METHOD: Rates of panic disorder in 142 first-degree relatives of patients who responded to sodium lactate, 88 first-degree relatives of patients who did not respond to sodium lactate, and 231 first-degree relatives of never mentally ill subjects were compared. RESULTS: No difference in familial transmission of panic disorder was found between the two patient groups. CONCLUSIONS: The findings do not support the notion that panic disorder subtypes are associated with lactate sensitivity.