Biological markers in depression

Temporal variation in Irish suicide rates

Using Irish suicide data for the period 1990-1998, the independent effects of month and day adjusting for age, gender, and calendar year effects and distinguishing between holiday and working Mondays were assessed. The male suicide rate was significantly higher on working Mondays (+31%) and Saturdays (+14%), and during April, June, and August (+17%), after adjustment for the other variables. In contrast, female suicide rates were higher only in August (+35%) and exhibited no day effect. Teenage men had a greater elevation of risk on Saturdays, Sundays, and both working and holiday Mondays than any other group. The study findings should be taken into account in the planning of specialized health care services and helplines for suicidal people. Furthermore, the findings provide support for Gabennesch's (1988) broken promise theory and the relationship between dysfunctions of the serotonergic system and suicidal behavior.

Polymorphonuclear (PMN) elastase levels in depressive disorders

The present study was carried out to determine polymorphonuclear (PMN) elastase levels and to explain whether or not altered levels may be a factor in depression. The patient group included a total of 68 patients with depression (32 with major depression, 36 with dysthymia). The control group included 40 volunteer, healthy subjects. WBC, erythrocyte sedimentation rate (ESR), immunogloblins (Ig A, IG G, IgM), and complements (C3 and C4) levels of the patient and control groups were determined. The mean PMN elastase levels, determined by immunoactivation method, in patients with major depression without and with melancholia, dysthymia and healthy subjects were found to be 99.5 (10.8) microgram(s)/L [arithmetic mean (SEM)], 289.0 (71.3) microgram(s)/L, 55.7(5.5) microgram(s)/L, and (47.3(2.6) microgram(s)/L, respectively. The mean PMN elastase level was found to be statistically higher in patients with depression, especially in patients with major depression, than that of healthy subjects. It was concluded that severe depression is associated with immunological and inflammatory alterations may be showed easily by PMN elastase measurements.

Platelet serotonin markers and depressive symptomatology

Dysfunction of brain serotonergic symptoms may be a factor in the mood and behavioral disturbances associated with depression. Platelet serotonin measures represent indirect but easily obtainable indices of brain serotonin function. To examine the specificity of relationships between cognitive and vegetative symptom groupings and platelet serotonin measures, we assessed 35 depressed outpatients using the Hamilton Rating Scale for Depression and collected platelets after a minimum 3-week drug-free period. Platelets were also collected from 14 controls. The results showed that depressed patients had lower platelet serotonin (5-HT) uptake site density values than controls and that 5-HT uptake site density values were inversely correlated with the severity of cognitive symptoms of depression. Platelet 5-HT2 receptor density values were higher in depressed patients than controls, and there was a trend toward a direct correlation between the cognitive symptoms of depression and 5-HT2 receptor density values. Neither platelet measure showed any relationship with the severity of the vegetative symptoms of depression.