Triggers for attempted suicide in Istanbul youth, with special reference to their socio-demographic background.

OBJECTIVE: Suicidal behavior of young people is a topic of utmost importance because suicide is irreversible, and should be prevented. Knowing about the psychosocial background and the triggering events could help in preventing suicidal behavior. We therefore aimed at identifying psychosocial factors that may trigger suicidal behavior in youth. METHODS: We analyzed retrospectively the standardized records of 2232 youths aged ≤25 years, who were treated after a suicide attempt at emergency units of public hospitals in Istanbul, Turkey during a period of 1 year. We describe this population according to sex and socio-economic conditions, like educational, occupational, relationship status and link them with their reported reasons for suicide attempts. RESULTS: The majority of patients were female (81.6%, N = 1822 females, 18.4%, N = 410 males). Independent of their educational and occupational background, patients indicated most frequently intra-familial problems (females 45.8%, males 30.5%), intrapersonal problems (females 19.9%, males 18.5%), and relationship problems (females 11.3%, males 23.9%) as triggering reasons. CONCLUSIONS: Because intra-familial problems were the most frequently reported triggers of suicide attempts, preventive measures should focus on handling intra-familial conflicts. As sex differences were observed for the second-most common trigger-reasons, prevention should also focus on differentially handling intrapersonal and relationship conflicts better.

Assessment of Ketamine Binding of the Serotonin Transporter in Humans with Positron Emission Tomography.

Background: Comprehensive description of ketamine's molecular binding profile becomes increasingly pressing as use in real-life patient cohorts widens. Animal studies attribute a significant role in the substance's antidepressant effects to the serotonergic system. The serotonin transporter is a highly relevant target in this context, because it is central to depressive pathophysiology and treatment. This is, to our knowledge, the first study investigating ketamine's serotonin transporter binding in vivo in humans. Methods: Twelve healthy subjects were assessed twice using [11C]DASB positron emission tomography. A total of 0.50 mg/kg bodyweight ketamine was administered once i.v. prior to the second positron emission tomography scan. Ketamine plasma levels were determined during positron emission tomography. Serotonin transporter nondisplaceable binding potential was computed using a reference region model, and occupancy was calculated for 4 serotonin transporter-rich regions (caudate, putamen, thalamus, midbrain) and a whole-brain region of interest. Results: After administration of the routine antidepressant dose, ketamine showed <10% occupancy of the serotonin transporter, which is within the test-retest variability of [11C]DASB. A positive correlation between ketamine plasma levels and occupancy was shown. Conclusions: Measurable occupancy of the serotonin transporter was not detectable after administration of an antidepressant dose of ketamine. This might suggest that ketamine binding of the serotonin transporter is unlikely to be a primary antidepressant mechanism at routine antidepressant doses, as substances that facilitate antidepressant effects via serotonin transporter binding (e.g., selective serotonin reuptake inhibitors) show 70% to 80% occupancy. Administration of high-dose ketamine is widening. Based on the positive relationship we find between ketamine plasma levels and occupancy, there is a need for investigation of ketamine's serotonin transporter binding at higher doses.