Seasonal influence on platelet 5-HT levels in patients with recurrent major depression and schizophrenia

The influence of daylight exposure on platelet 5-HT levels in patients with major depression and schizophrenia

“…This finding is in agreement with our previous results showing no seasonal influence on platelet 5-HT concentrations in schizophrenic patients [38]. The literature data on the circadian rhythm and melatonin secretion in schizophrenic patients is scarce and often contradictory.…”

“…Previous studies have shown unchanged [34a,b] or decreased [35] platelet 5-HT concentration in depressed patients. In schizophrenic patients platelet 5-HT concentration was increased [36][37][38] or unaltered [39][40]. There are several studies reporting altered platelet 5-HT uptake depending on the season in depressed [41][42] and schizophrenic [43] patients and indicating that in schizophrenic patients platelet 5-HT levels depend on the season of birth [44].…”

Platelet serotonin in combat related posttraumatic stress disorder with psychotic symptoms

“…Platelet 5-HT concentration might be affected by sex, age or seasonality. The effect of sex was excluded with the inclusion of only male subjects; the possible effect of age on platelet 5-HT content was 6 6 neglected as no significant relation between age and platelet 5-HT was found in healthy (Muck-Seler et al, 1996b;Pivac et al, 2001;Pivac et al, 2004b) or PTSD (present study) subjects, and the possible seasonal influence on platelet 5-HT parameters (Jakovljevic et al, 1997) was avoided since war veterans and healthy controls were sampled in the same season.…”

Antipsychotics do not affect platelet serotonin in schizophrenic patients

“…A recent study [24] showed no changes in mean platelet 5-HT content between acute psychiatric patients treated with secondary antipsychotics, lithium, neuroleptics and stabilizers, and our present and previous [17] results confirmed this finding. [25,26].…”