An association between low levels of 5-HIAA and HVA in cerebrospinal fluid and early mortality in a diagnostically mixed psychiatric sample

Early death and CSF monoamine metabolites in schizophrenia spectrum psychosis

INTRODUCTION

Patients with schizophrenia have higher rates of mortality than the general population. Lower concentrations of the cerebrospinal fluid (CSF) monoamine metabolites homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) have been associated with suicidal, aggressive and impulsive behavior. Mortality has been suggested as a measure of impulsivity and a relationship between early death and lower concentrations of CSF monoamine metabolites has been reported but the studies are few with short periods of follow-up and small numbers.

AIM

The objective of this study was to investigate a relationship between early death and concentrations of CSF 5-HIAA and HVA.

METHODS

Three hundred and eighty-five inpatients with schizophrenia spectrum psychosis were lumbar punctured in a standardized manner and followed for a median of 26 years. Patients were searched to identify those who had died. Causes of death were obtained from the Causes of Death Register.

RESULTS

During the time of follow-up, 97 patients died. Schizophrenia spectrum psychosis patients died at an earlier age from both natural and unnatural causes of death. No significant associations were found between CSF 5-HIAA and HVA concentrations and non-suicidal death. Attempted suicide was not a risk factor for non-suicidal death at younger age.

CONCLUSION

Patients with schizophrenia spectrum psychosis die at an earlier age from both natural and unnatural causes of death. Attempted suicide is not a risk factor for non-suicidal death at younger age. Low concentrations of CSF HVA and 5-HIAA were not a risk factor for non-suicidal death at younger age in schizophrenia spectrum psychosis.

The evolution of violence in men: the function of central cholesterol and serotonin

Numerous studies point to central serotonin as an important modulator of maladaptive behaviors. In men, for instance, low concentrations of this neurotransmitter are related to hostile aggression. A key player in serotonin metabolism seems to be central cholesterol. It plays a fundamental role in maintaining the soundness of neuron membranes, especially in the exocytosis transport of serotonin vesicles into the synaptic cleft. In this review, we attempt an evolutionary approach to the neurobiological basis of human male violence. Hominid evolution was shaped by periods of starvation but also by energy demands of an increasingly complex brain. A lack of food resources reduces uptake of glucose and results in a decreased energy-supply for autonomous brain cholesterol synthesis. Consequently, concentrations of neuromembrane cholesterol decrease, which lead to a failure of the presynaptic re-uptake mechanism of serotonin and ultimately to low central serotonin. We propose that starvation might have affected the larger male brains earlier than those of females. Furthermore, this neurophysiological process diminished the threshold for hostile aggression, which in effect represented a prerequisite for being a successful hunter or scavenger. In a Darwinian sense, the odds to acquire reliable energetic resources made those males to attractive spouses in terms of paternal care and mate support. To underpin these mechanisms, a hypothetical four-stage model of synaptic membrane destabilization effected by a prolonged shortage of high-energy, cholesterol-containing food is illustrated.

Serotonergic influences on life-history outcomes in free-ranging male rhesus macaques

Several studies have demonstrated that nonhuman primate males with low cerebrospinal fluid (CSF) levels of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) exhibit antisocial behavior patterns. Included in these deleterious patterns are impulse control deficits associated with violence and premature death. No studies to date have longitudinally studied the long-term outcome of young subjects with low CSF 5-HIAA concentrations as they mature into adults. In this study we examined longitudinal relations among serotonergic and dopaminergic functioning, as reflected in CSF metabolite concentrations, aggression, age at emigration, dominance rank, and mortality in free-ranging rhesus macaque (Macaca mulatta) males. Our results indicate long-term consistency of individual differences in levels of 5-HIAA in CSF in the subject population from the juvenile period of development through adulthood. We found a significant negative correlation between 5-HIAA concentrations measured in juveniles and rates of high-intensity aggression in the same animals as adults. Further, CSF 5-HIAA concentrations were lower in juveniles that died than in animals that survived. For the young animals that migrated there was a positive correlation between CSF 5-HIAA concentration and age at emigration, whereas for the animals that remained in their troop until later in sexual maturity there was a negative correlation between CSF 5-HIAA concentration and age of emigration. After animals emigrated to a new troop, social dominance rank in the new troop was positively correlated with early family social dominance rank, but inversely correlated with juvenile CSF 5-HIAA concentrations. Taken together, our findings suggest that males with low central serotonin levels early in life delay migration and show high levels of violence and premature death, but the males that survive achieve high rank. These findings indicate that longitudinal measures of serotonergic and dopaminergic functioning are predictive of major life-history outcomes in nonhuman primate males. Low concentrations of CSF 5-HIAA are associated with negative life-history patterns characterized by social instability and excessive aggression, and positive life-history patterns characterized by higher dominance rank.

A review of prospective studies of biologic predictors of suicidal behavior in mood disorders

Predicting suicide is difficult due to the low base rate, even in high-risk groups, and the multi-causal nature of suicidal behavior. Clinical predictors have shown low specificity. Retrospective and cross-sectional studies have identified a number of biologic anomalies associated with suicide and suicide attempt. Prospective studies provide estimates of the predictive utility of biologic measures. Here we review prospective studies of suicidal behavior and serotonergic, noradrenergic, dopaminergic and hypothalamic-pituitary-adrenocortical axis function in mood disorders. The most promising biologic predictors are low CSF 5-HIAA and HPA axis dysfunction as demonstrated by dexamethasone non-suppression that are each associated with about 4.5 fold greater risk of suicide.

Evolutionary underpinnings of excessive alcohol consumption

Given our close phylogenetic relatedness, non-human primates, in principle, could serve as an ideal model for alcoholism. Indeed, many studies in both humans and rhesus macaques show relationships between excessive alcohol consumption, aggression and serotonergic function, as measured by concentrations of the principal metabolite of serotonin, 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid (CSF). An important behavioral predictor of excessive alcohol consumption in both humans and rhesus monkeys is the propensity toward impulsivity. Integrating behavioral and neuroendocrine data from captive and semi-free-ranging rhesus macaques, we posit that benefits derived from impulsive and aggressive behaviors in some contexts might contribute indirectly to the maintenance of traits involved in alcoholism and excessive alcohol intake.

ADHD, aggression, and antisocial behavior across the lifespan. Interactions with neurochemical and cognitive function

The progression to adult antisocial behavior is the least desirable developmental trajectory for children with ADHD. An unremitting pattern of physical aggression appears of great import when predicting long-term outcome. However, a profile characterized by behavioral and cognitive impulsivity and emotional lability may indicate a greater likelihood of the progression to adult antisocial behavior and violent impulse-control disorders. This constellation of behaviors appears to be, at least in part, mediated by brain serotonergic systems. The contribution of cognitive impairments, as manifested by executive function deficits, diminished moral reasoning, and impaired empathic ability, to the emergence and persistence of antisocial behavior has yet to be discerned.

CSF 5-HIAA levels are lower in impulsive as compared to nonimpulsive violent suicide attempters and control subjects

BACKGROUND

We studied CSF 5-HIAA and HVA concentrations in violent suicide attempters and examined their relationship with depression, anxiety, and impulsivity.

METHODS

CSF 5-HIAA and HVA concentrations were determined very shortly after hospital admission and compared to those of a matched control population. Clinical evaluation was performed concomitantly; the level impulsivity was evaluated by the Impulsivity Rating Scale (IRS).

RESULTS

Twenty-three patients and 23 control subjects were included. According to the IRS, 14 patients were classified as impulsive, including all patients suffering from personality disorders, and 9 as nonimpulsive, with a main DSM-IIIR diagnosis of melancholia. CSF 5-HIAA concentrations in the suicide group were significantly lower than in control subjects. This difference was entirely due to the impulsive suicide attempters. There was an inverse correlation between the IRS score and CSF 5-HIAA (r = -.47, p = .02) and only a trend for HVA (r = -.41, p = .078) levels in the suicide group.

CONCLUSIONS

This study of a group of violent suicide attempters distinguished a subgroup of patients diagnosed with personality disorder with high impulsivity scores and a subgroup of patients with the main diagnosis of severe depression. CSF 5-HIAA was significantly lower in impulsive violent attempters than in nonimpulsive violent attempters, therefore desintangling violence from impulsivity and linking this biologic abnormality to impulsivity.

Family psychiatric history, cerebrospinal fluid monoamine metabolites, and temperament in infants

BACKGROUND

Variations in cerebrospinal fluid (CSF) levels of the monoamine metabolites 5-hydroxyindoleacetic acid, 3-methoxy-4-hydroxyphenylglycol, and homovanillic acid have been associated with behavioral abnormalities in nonhuman primates, and with psychopathology in studies of children and adults.

METHODS

We assayed monoamine metabolites in "left-over" spinal fluid from 167 neurologically normal newborn infants (0-3 months of age), and later (at age 18-21 months of age) obtained their family psychiatric histories and assessed their temperament using the Colorado Childhood Temperament Inventory (CCTI).

RESULTS

Family history of antisocial personality disorder predicted significantly lower scores for soothability (p = .003) at 18-21 months. There were no statistically significant associations between newborn monoamine metabolite levels and any aspect of temperament on the CCTI.

CONCLUSIONS

These findings suggest complex relationships between genetic liability for psychiatric disorders and CSF monoamine metabolite levels; those relationships do not seem to be mediated by infant temperament. It appears likely that interindividual differences in monoamine metabolite levels change over the course of development in humans.

Neurotransmitters and suicidal behavior. The evidence from cerebrospinal fluid studies

Studies of neurotransmitter metabolites in cerebrospinal fluid (CSF) were initially focused on depressive illness. Although several studies have demonstrated low concentrations of the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA), and the dopamine metabolite, homovanillic acid (HVA), in depressed patients, these early studies may have been biased by concomitant administration of antidepressant drugs (which tend to lower CSF 5-HIAA), amount of CSF drawn (there is a concentration gradient for both metabolites), and selection of control subjects. Once these methodological details are controlled for, the differences between depressed patients and controls are unimpressive. However, there is a remarkably consistent association between low concentrations of CSF 5-HIAA and suicidal behavior, as evidenced by over 20 studies. The association is not confined to depressive illness but has also been found in schizophrenia, personality disorder, and certain impulse control disorders (but, interestingly, not in bipolar disorder). A low concentration of CSF 5-HIAA in a suicide attempter is associated with a substantial increase in short-term suicide risk. CSF studies in violent criminals, and in nonhuman primates, suggest that aggression dyscontrol may partly explain the association between suicide and serotonin, which is of considerable theoretical interest. CSF 5-HIAA determinations may also be helpful in the clinical assessment of suicide risk.

CSF 5-HIAA, testosterone, and sociosexual behaviors in free-ranging male rhesus macaques in the mating season

This study examines sexual behavior, serotonin turnover in the central nervous system, and testosterone in free-ranging non-human primates. Study subjects were 33 young adult male rhesus macaques (Macaca mulatta) living in naturalistic social groups on a 475-acre South Carolina barrier island. Blood and cerebrospinal fluid (CSF) samples were obtained during random trappings, and the subjects were located for observation by radio telemetry. Quantitative behavioral samples totaling 203 observation hours were taken during two mating seasons (September through January) in 1994 and 1995. Control observations (65 h) on 13 subjects were also taken during the non-mating seasons in 1994 and 1995. The results indicate that CSF 5-hydroxyindoleacetic acid (5-HIAA), CSF testosterone, and plasma testosterone concentrations increase significantly during the mating season. During the mating season, there were significant increases in high intensity aggression, low intensity aggression, grooming behavior, and heterosexual mounting. In the mating season, CSF 5-HIAA was significantly correlated with several sociosexual behaviors: consorts per hour, heterosexual mounts per hour, and inseminations per hour. In contrast to previous findings from the non-mating season, CSF 5-HIAA was not correlated with any measures of aggression or sociality, although during consorting, CSF 5-HIAA was positively correlated with grooming. From these findings, we conclude that the lack of correlation between intense and severe aggression and CSF 5-HIAA in the mating season may reflect the use of high intensity aggression in 'normative' male-male competition over access to reproductively active females. We also conclude that CNS serotonin turnover is positively correlated with sexual competence, i.e. males with low CSF 5-HIAA concentrations are less sexually competent than males with higher concentrations.