Relationships between hormonal profile and novelty seeking in combat-related posttraumatic stress disorder.

This study examines relationships between hormonal levels and novelty seeking in a group of 27 Vietnam veterans with combat-related posttraumatic stress disorder (PTSD). Novelty seeking in the veteran sample, measured by the Cloninger Tridimensional Personality Questionnaire (TPQ), was almost twice as high as previously published norms. A distinctive pattern of significant positive correlations was found between novelty seeking scores and serum total triiodothyronine (T3), free T3, the T3/free thyroxine (FT4) ratio, urinary norepinephrine and the norepinephrine/cortisol ratio, while a negative correlation was found between novelty seeking scores and urinary cortisol levels. The findings were confirmed by t test analyses of high vs low novelty seeking subgroups and do not appear to be related simply to the severity of PTSD. These preliminary findings indicate the need to include measures of characterological traits in psychoendocrine studies of PTSD and to investigate their possible usefulness in subtyping this disorder.