Neurochemical variables in subjects with adjustment disorder after suicide attempts

The investigation of biological correlates of suicidal behavior is important for identifying high-risk subjects. The objective of this study was to examine the neurochemical variables' platelet MAO activity and urinary MHPG, 5HIAA and HVA, the main metabolites of noradrenaline, serotonin and dopamine, neurotransmitters that are considered to be involved in the pathophysiology of suicidal behavior, as well as plasma cortisol, in a group of subjects with adjustment disorder after a suicide attempt. Fifty-three patients, 42 females and 11 males, were included in the study and were compared to a group of 50 healthy controls, 25 females and 25 males. Platelet MAO activity was found to be significantly lower in both male and female patients compared to controls of the same sex (P < 0. 001 for both comparisons). 5HIAA and HVA were not different between patients and controls, but MHPG was significantly higher in the patients group (P = 0.008). Moreover, plasma levels of cortisol were significantly higher in the patients compared to the controls (P < 0. 001). Our results confirm the hypothesis of low platelet MAO activity as a biological characteristic of patients who attempt suicide. They also point to a possible parallel activation of the noradrenergic system.