BACKGROUND: The serotonergic system is implicated in the pathophysiology of 
posttraumatic stress disorder (PTSD) and depression. The present study focused 
on platelet serotonin (5-HT) concentration and symptoms of comorbid depression 
in war veterans with or without PTSD.
METHODS: PTSD and depression were evaluated using Clinician Administered PTSD 
Scale, Davidson Trauma Scale, Montgomery-Asberg Depression Rating Scale and 
Hamilton Anxiety Scale. Sixty-five male drug-free war veterans (48 with PTSD and 
17 without PTSD) and 65 age- and sex-matched healthy controls were studied.
RESULTS: Comorbid depression occurred in 54 and 31% of war veterans with PTSD 
and without PTSD, respectively. Platelet 5-HT concentration was similar in the 
groups of depressed and nondepressed war veterans with or without PTSD and 
healthy controls. Platelet 5-HT concentration was found to differ between war 
veterans with various degrees of appetite loss. A positive correlation was 
observed between platelet 5-HT concentration and severity of appetite loss in 
veterans with PTSD. There was no relationship between platelet 5-HT 
concentration and severity of other symptoms of PTSD or depression.
LIMITATIONS: War veterans included in the study were outpatients.
CONCLUSIONS: War veterans with PTSD had a high incidence of comorbid depression, 
that was not related to platelet 5-HT concentration. The marked relationship 
between platelet 5-HT concentration and severity of appetite loss, suggested 
that 5-HT system is involved in the regulation of appetite, at least in 
depressed war veterans with PTSD.