Neuroendocrine Aspects of Suicidal Behavior

The effect of oral dexamethasone administration on testosterone levels in combat veterans with or without a history of suicide attempt

Combat exposure has been linked to increased risk of suicidal ideation, suicide attempts, and death by suicide, and suicidality has been linked with altered testosterone levels. In this study, we examined morning baseline free and total testosterone levels and the effect of dexamethasone administration on testosterone levels in male combat veterans with or without a history of suicide attempt. Demographic and clinical parameters of the study participants were assessed and recorded. Blood samples were collected between 8:00 and 8:30 a.m. on the day prior to and following dexamethasone (0.5 mg) ingestion. Suicide attempters had higher schedule for suicidal ideation (SSI) scores in comparison to non-attempters. Baseline free and total testosterone levels were lower in suicide attempters compared to non-attempters. In the whole sample, both baseline free and total testosterone levels negatively correlated with SSI scores. Free testosterone levels decreased after dexamethasone administration among non-attempters but not among attempters. Free testosterone post-dexamethasone levels positively correlated with aggression scores among non-attempters but not among suicide attempters. Our findings indicate that there are substantial differences in the testosterone regulation between combat veterans with or without a history of suicide attempt. Studies of the relation between the testosterone function and suicidal behavior among combat veterans may lead to improvement in detection of suicidality and finding new pharmacological targets for prevention of suicide among veterans.

Serum ghrelin and cholesterol values in suicide attempters

In our previous study, we demonstrated that suicide attempters had statistically significant lower leptin and cholesterol levels compared with healthy controls. In keeping with our previous report regarding lower serum cholesterol and leptin levels in suicide attempters compared with healthy controls, the relationship between cholesterol and leptin, and ghrelin, we aimed to evaluate serum total cholesterol and ghrelin levels in suicide attempters. In the present study, 30 patients with suicide attempts (aged 18-47 years) and the same number of healthy controls were compared with regard to serum total cholesterol and ghrelin levels. The mean cholesterol level of the patients was significantly lower than that of the controls. On the other hand, the suicide attempters had significantly higher ghrelin levels compared with the controls. The results suggest that suicide attempts seem to be associated with decreased serum cholesterol and higher ghrelin values.

Sudden death and suicide: a comparison of brain weight

BACKGROUND

Recent evidence suggests that the brain weight of individuals over the age of 60 who commit suicide is significantly higher than in those who die of natural causes.

AIMS

To ascertain whether brain weight is different in people of a younger age who commit suicide than in those who die accidentally.

METHOD

A retrospective review of post-mortem reports collecting height, weight and brain weight in 100 suicide victims (87 males, mean age 38.5 years) and 100 age/gender-matched controls who died accidentally or of natural causes (87 males, mean age 38.7 years). Comparison by t-test was made of brain weight in isolation as well as brain weight corrected for height, weight and body mass index.

RESULTS

These results reveal no significant difference in brain weight in suicide cases compared to the general population (P > 0.05). The brain weight of those who died by hanging was significantly higher than of those who died by overdose.

CONCLUSIONS

Whatever the significant neuropsychiatric elements are that influence suicidal behaviour, they do not consistently affect brain weight in the population studied.

The relationship between menstrual cycle phases and suicide attempts

OBJECTIVE

The validity of prior studies on the menstrual cycle and suicide attempts assumes that suicidal women accurately describe their cycles. The three objectives of this study were 1) to explore whether prior inconsistencies are due to the effects of sample selection and method of assessment of the menstrual cycle, 2) to assess the relationship between the menstrual cycle phase and suicide attempts, and 3) to establish the role of sexual hormones in suicide attempts.

METHODS

The original sample included 134 women who came to the emergency room of a general hospital after a suicide attempt. One hundred eight female blood donors were recruited as control subjects. The menstrual cycle was divided into follicular, midcycle, and luteal phases using two clinical methods and serum hormonal assessment. Dividing the follicular phase into menstrual and nonmenstrual phases was also considered.

RESULTS

Two of 11 previously used sampling methods produced a sample size similar to that of the hormonal assessment. kappa values between the two clinical and the endocrinological methods were low (0.40-0.50). The number of suicide attempts during the follicular phase (particularly during the menstrual phase) was significantly higher than expected.

CONCLUSIONS

Despite the inability to control for other variables and limitations, the results of this study suggest that sample selection could introduce biases and that studies relating psychiatric symptomatology and menstrual cycle phases need to use hormonal determinations. New studies are needed to verify that suicide attempts are more frequent during the follicular phase (particularly during the menstrual phase).

Alterations of corticotropin releasing hormone (CRH) and neuropeptide Y (NPY) plasma levels in mood disorder patients with a recent suicide attempt

In order to receive a further understanding of stress-regulation in depressed suicide attempters, peptides that are supposed to be related to the stress system (the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system) were studied in plasma. When compared with healthy controls, cortisol was high (p<0.001) and corticotropin releasing hormone (CRH) and neuropeptide Y (NPY) appeared to be low (p<0.001) in patients who had recently attempted suicide. Patients who had repeatedly attempted suicide had the lowest NPY. A correlation between NPY and cortisol (p<0.05) was found in suicidal patients with depression NOS, whereas beta-endorphins correlated with cortisol (p<0.01) in suicidal patients with major depressive disorder. A postdexamethasone decrease of NPY was noted in the controls but not in the patients. These results suggest stress system alterations in suicidal patients with mood disorders.

Neuroendocrine challenge studies of suicidal behavior

This article reviews the research data regarding human neuroendocrine systems and suicidal behavior. Special emphasis is placed on pharmacochallenge studies. Such studies uniquely allow for functional assessment of neuroendocrine parameters in living subjects. Serotonergic mechanisms have been the most fruitful areas of research. While discussing the major areas of controversy, theoretical approaches to integration are offered.

Suicidal behavior is attenuated in patients with multiple sclerosis by treatment with electromagnetic fields

A marked decrease in the levels of serotonin (5-HT) and its metabolite (5-HIAA) has been demonstrated in postmortem studies of suicide victims with various psychiatric disorders. Depression is the most common mental manifestation of multiple sclerosis (MS) which accounts for the high incidence of suicide in this disease. CSF 5-HIAA concentrations are reduced in MS patients and nocturnal plasma melatonin levels were found to be lower in suicidal than in nonsuicidal patients. These findings suggest that the increased risk of suicide in MS patients may be related to decreased 5-HT functions and blunted circadian melatonin secretion. Previous studies have demonstrated that extracerebral applications of pulsed electromagnetic fields (EMFs) in the picotesla range rapidly improved motor, sensory, affective and cognitive deficits in MS. Augmentation of cerebral 5-HT synthesis and resynchronization of circadian melatonin secretion has been suggested as a key mechanism by which these EMFs improved symptoms of the disease. Therefore, the prediction was made that this treatment modality would result in attenuation of suicidal behavior in MS patients. The present report concerns three women with remitting-progressive MS who exhibited suicidal behavior during the course of their illness. All patients had frequent suicidal thoughts over several years and experienced resolution of suicidal behavior within several weeks after introduction of EMFs treatment with no recurrence of symptoms during a follow-up of months to 3.5 years. These findings demonstrate that in MS pulsed applications of picotesla level EMFs improve mental depression and may reduce the risk of suicide by a mechanism involving the augmentation of 5-HT neurotransmission and resynchronization of circadian melatonin secretion.

Suicide: risk factors and therapeutic considerations in the emergency department

Emergency physicians often encounter covertly and overtly suicidal patients, and can thus play a key role in the prevention of suicide. The epidemiology and diverse presentations of suicidal behavior are reviewed. We then provide a detailed approach to the assessment of suicide risk, and criteria for safe discharge from the emergency department (ED). Finally, management considerations for the ED are discussed.

The behavioral neurobiology of self-injurious behavior in rhesus monkeys

1. Self-injurious behavior (SIB) is prevalent among institutionalized children, but the efficacy of current behavioral and pharmacological treatments is marginal. 2. There is evidence that SIB in humans has a neurobiological basis. A better understanding of the neurobiological factors that may promote or cause SIB is necessary for the development of effective pharmacologic treatments. 3. SIB that is similar in some respects to SIB in humans occurs in nonhuman primates that have been deprived of social experience early in life. An analysis of the "cause" of SIB suggests that it is a relatively straight-forward example of the development of neurobiological and behavioral aspects of aggressive behavior in the absence of social factors that would normally bring the behavior under environmental control. Once induced, however, it becomes environmentally autonomous and its proximal cause is neurobiological in nature. 4. There are three lines of evidence that nonhuman primate SIB is linked to malfunctions in the norepinephrine (NE) and serotonin (5HT) neurotransmitter systems. The activity of these systems appears to be altered by psychosocial deprivation. The functional relationship between the two systems appears to be altered or absent in socially deprived monkeys. Pharmacologic agents that act on these systems alter SIB in monkeys. 5. Preliminary data from socially deprived rhesus monkeys are consistent in major respects with studies linking altered serotonin systems to self-injurious behavior and suicidal motivation in humans who also probably suffer from social deprivation. 6. Taken together, these findings indicate that developmental study of biogenic amine systems, particularly finding ways to circumvent deficits in, or restore functional linkages between, the 5HT and NE systems, will lead to a greater understanding of the neurobiologic basis of SIB in humans and animals and will enable us to develop more effective treatments of SIB.