Studies of CSF 5-HIAA in depression and suicidal behaviour

Biomarker-Guided Tailored Therapy in Major Depression

This chapter provides a comprehensive examination of a broad range of biomarkers used for the diagnosis and prediction of treatment outcomes in major depressive disorder (MDD). Genetic, epigenetic, serum, cerebrospinal fluid (CSF), and neuroimaging biomarkers are analyzed in depth, as well as the integration of new technologies such as digital phenotyping and machine learning. The intricate interplay between biological and psychological elements is emphasized as essential for tailoring MDD management strategies. In addition, the evolving link between psychotherapy and biomarkers is explored to uncover potential associations that shed light on treatment response. This analysis underscores the importance of individualized approaches in the treatment of MDD that integrate advanced biological insights into clinical practice to improve patient outcomes.

Prenatal SAMe Treatment Induces Changes in Brain Monoamines and in the Expression of Genes Related to Monoamine Metabolism in a Mouse Model of Social Hierarchy and Depression, Probably via an Epigenetic Mechanism

Reduction in the levels of monoamines, such as serotonin and dopamine in the brain, were reported in patients and animals with depression. SAMe, a universal methyl donor and an epigenetic modulator, is successfully used as an adjunct treatment of depression. We previously found that prenatal treatment with SAMe of Submissive (Sub) mice that serve as a model for depression alleviated many of the behavioral depressive symptoms. In the present study, we treated pregnant Sub mice with 20 mg/kg of SAMe on days 12–15 of gestation and studied the levels of monoamines and the expression of genes related to monoamines metabolism in their prefrontal cortex (PFC) at the age of 3 months. The data were compared to normal saline-treated Sub mice that exhibit depressive-like symptoms. SAMe increased the levels of serotonin in the PFC of female Sub mice but not in males. The levels of 5-HIAA were not changed. SAMe increased the levels of dopamine and of DOPAC in males and females but increased the levels of HVA only in females. The levels of norepinephrine and its metabolite MHPG were unchanged. SAMe treatment changed the expression of several genes involved in the metabolism of these monoamines, also in a sex-related manner. The increase in several monoamines induced by SAMe in the PFC may explain the alleviation of depressive-like symptoms. Moreover, these changes in gene expression more than 3 months after treatment probably reflect the beneficial effects of SAMe as an epigenetic modulator in the treatment of depression.

Cerebrospinal fluid levels of monoamines among suicide attempters: A systematic review and random-effects meta-analysis

BACKGROUND

It remains unclear whether the dopaminergic and noradrenergic systems may be implied in suicide attempt risk. In addition, although the serotonergic system has been extensively studied, no formal meta-analysis has been performed to examine its association with suicide attempt.

METHODS

Using PRISMA methodology, we performed a systematic literature review and random-effects meta-analyses of the differences in cerebrospinal fluid (CSF) levels of 5-HIAA, HVA and MHPG between suicide attempters and individuals who never attempted suicide.

RESULTS

We identified 30 studies including 937 suicide attempters and 1128 non-attempters; 29 of them measured CSF levels of 5-HIAA, 22 measured CSF levels of HVA and 14 measured CSF levels of MHPG. CSF levels of 5-HIAA and HVA were significantly lower in suicide attempters than in non-attempters [SMD = -0.43 (95% CI: -0.71 to -0.15; p < 0.01) and SMD = -0.45 (95% CI: -0.72 to -0.19; p < 0.01), respectively]. We did not find a significant association between CSF MHPG levels and suicide attempt.

LIMITATIONS

Our analyses relied on a limited number of studies of good quality and most studies included small sample sizes.

CONCLUSION

Both serotonin and dopamine systems may play a role in suicide attempt risk. Our findings suggest that a silo approach to biomarkers should be phased out in favor of the study of multiple systems in parallel and in the same populations to progress in the identification of the biological components independently associated with suicide risk, with the goal of identifying new treatment targets and improving suicide risk prediction.

MDGA1-deficiency attenuates prepulse inhibition with alterations of dopamine and serotonin metabolism: An ex vivo HPLC-ECD analysis

MDGA1 (MAM domain-containing glycosylphosphatidylinositol anchor) has recently been linked to schizophrenia and bipolar disorder. Dysregulation of dopamine (DA) and serotonin (5-HT) systems has long been associated with schizophrenia and other neuropsychiatric disorders. Here, we measured prepulse inhibition (PPI) of the startle response and ex vivo tissue content of monoamines and their metabolites in the frontal cortex, striatum and hippocampus of Mdga1 homozygous (Mdga1-KO), Mdga1 heterozygous (Mdga1-HT) and wild-type (WT) male mice. We found that Mdga1-KO mice exhibited statistically significant impairment of PPI, and had higher levels of homovanillic acid in all three brain regions studied compared with Mdga1-HT and WT mice (P < 0.05), while levels of norepinephrine, DA and its metabolites 3,4-dihydroxyphenylacetic acid and 3-methoxytyramine remained unchanged. Mdga1-KO mice also had a lower 5-hydroxyindoleacetic acid level in the striatum (P < 0.05) compared with WT mice. 5-HT levels remained unchanged with the exception of a significant increase in the level in the cortex. These data are the first evidence suggesting that MDGA1 deficiency leads to a pronounced deficit in PPI and plays an important role in perturbation of DA and 5-HT metabolism in mouse brain; such changes may contribute to a range of neuropsychiatric disorders.

"Out, out, brief candle! Life's but a walking shadow": 5-HTTLPR Is Associated With Current Suicidal Ideation but Not With Previous Suicide Attempts and Interacts With Recent Relationship Problems

BACKGROUND

Suicide is an unresolved psychiatric and public health emergency, claiming 800,000 lives each year, however, its neurobiological etiology is still not understood. In spite of original reports concerning the involvement of 5-HTTLPR in interaction with recent stress in the appearance of suicidal ideation and attempts, replication studies have yielded contradictory results. In our study, we analyzed the association between 5-HTTLPR and lifetime suicide attempts, current suicidal ideation, hopelessness and thoughts of death as main effects, and in interaction with childhood adversities, recent stress, and different types of recent life events in a general population sample.

METHODS

Two thousand and three hundred fifty-eight unrelated European volunteers were genotyped for 5-HTTLPR, provided phenotypic data on previous suicide attempts, and current suicidal ideation, hopelessness and thoughts about death, and information on childhood adversities and recent life events. Logistic and linear regression models were run with age, gender, and population as covariates to test for the effect of 5-HTTLPR as a main effect and in interaction with childhood adversities and recent life events on previous suicide attempts and current suicidal ideation. Benjamini-Hochberg FDR Q values were calculated to correct for multiple testing.

RESULTS

5-HTTLPR had no significant effect on lifetime suicide attempts either as a main effect on in interaction with childhood adversities. 5-HTTLPR had a significant main effect on current suicidal ideation in the dominant model (Q=0.0344). 5-HTTLPR did not interact with childhood adversities or total number of recent life events on any phenotypes related to current suicidal risk, however, a significant interaction effect between 5-HTTLPR and current relationship problems emerged in the case of current suicidal ideation in the dominant model (Q=0.0218) and in the case of thoughts about death and dying in the dominant (Q=0.0094) and additive models (Q=0.0281).

CONCLUSION

While 5-HTTLPR did not influence previous suicide attempts or interacted with childhood adversities, it did influence current suicidal ideation with, in addition, an interaction with recent relationship problems supporting the involvement of 5-HTTLPR in suicide. Our findings that 5-HTTLPR impacts only certain types of suicide risk-related behaviors and that it interacts with only distinct types of recent stressors provides a possible explanation for previous conflicting findings.

Overcoming Resistance to Selective Serotonin Reuptake Inhibitors: Targeting Serotonin, Serotonin-1A Receptors and Adult Neuroplasticity

Major depressive disorder (MDD) is the most prevalent mental illness contributing to global disease burden. Selective serotonin (5-HT) reuptake inhibitors (SSRIs) are the first-line treatment for MDD, but are only fully effective in 30% of patients and require weeks before improvement may be seen. About 30% of SSRI-resistant patients may respond to augmentation or switching to another antidepressant, often selected by trial and error. Hence a better understanding of the causes of SSRI resistance is needed to provide models for optimizing treatment. Since SSRIs enhance 5-HT, in this review we discuss new findings on the circuitry, development and function of the 5-HT system in modulating behavior, and on how 5-HT neuronal activity is regulated. We focus on the 5-HT1A autoreceptor, which controls 5-HT activity, and the 5-HT1A heteroreceptor that mediates 5-HT actions. A series of mice models now implicate increased levels of 5-HT1A autoreceptors in SSRI resistance, and the requirement of hippocampal 5-HT1A heteroreceptor for neurogenic and behavioral response to SSRIs. We also present clinical data that show promise for identifying biomarkers of 5-HT activity, 5-HT1A regulation and regional changes in brain activity in MDD patients that may provide biomarkers for tailored interventions to overcome or bypass resistance to SSRI treatment. We identify a series of potential strategies including inhibiting 5-HT auto-inhibition, stimulating 5-HT1A heteroreceptors, other monoamine systems, or cortical stimulation to overcome SSRI resistance.

Autophagy inhibition plays a protective role against 3, 4-methylenedioxymethamphetamine (MDMA)-induced loss of serotonin transporters and depressive-like behaviors in rats

The 3,4-methylenedioxymethamphetamine (MDMA) is a popular recreational drug, which ultimately leads to serotonergic (5-HT) neurotoxicity and psychiatric disorders. Previous in vitro studies have consistently demonstrated that MDMA provokes autophagic activation, as well as damage of 5-HT axons and nerve fibers. So far, whether autophagy, a well-conserved cellular process that is critical for cell fate, also participates in MDMA-induced neurotoxicity in vivo remains elusive. Here, we first examined time-course of autophagy-related changes during repeated administration of MDMA (10 mg/kg s.c. twice daily for 4 consecutive days) using immunofluorescent staining for tryptophan hydroxylase and microtubule-associated protein 1 light chain 3 beta in rats. We also evaluated the protective effects of 3-methyadanine (3-MA, an autophagy inhibitor, 15 mg/kg i.p.) against MDMA-induced acute and long-term reductions in serotonin transporters (SERT) density in various brain regions using immunohistochemical staining and positron emission tomography (PET) imaging respectively. Plasma corticosterone measurements and forced swim tests were performed to evaluate the depressive performance. The staining results showed that repeated administration of MDMA increased expression of autophagosome and caused reduction in SERT densities of striatum and frontal cortex, which was ameliorated in the presence of 3-MA. PET imaging data also revealed that 3-MA could ameliorate MDMA-induced long-term decreased SERT availability in various brain regions of rats. Furthermore, immobility time of forced swim tests and plasma corticosterone levels were less in the group of MDMA co-injected with 3-MA compared with that of MDMA group. Together, these findings suggest that autophagy inhibition may confer protection against neurobiological and behavioral changes induced by MDMA.

Attitudes Toward Suicide: Past, Present and Future

This article maintains that it is important to understand how any given society views the act of suicide. It traces the forces that have shaped attitudes toward suicide in the Western world, documenting the change from viewing suicide as a sin to viewing it as a mental health problem. It also discusses recent methods of assessing attitudes toward suicide, including both normed and non-normed approaches. Finally, it calls for new types of research in the area of attitudes toward suicide that will permit finer-grained analyses of this most complex human behavior.

Psychopharmacological Agents and Suicide Risk Reduction: Ketamine and Other Approaches

Suicide is a major global public health problem and the leading cause of injury mortality in the USA. Suicide is a complex phenomenon involving several systems and neurobiological pathways, with interacting genetic and environmental mechanisms. The literature on the neurobiology and pharmacotherapy of suicide has been limited. To date, no medications have proven efficacious for treating acute suicidal crises. There is an emerging literature supporting a rapid anti-suicidal effect of ketamine, a non-competitive N-methyl-D-aspartate (NMDA) glutamate receptor antagonist, among depressed patients with suicidal ideation. Potential ketamine's anti-suicidal effect mechanisms are linked to interruption of the kynurenine pathway and modulating pro-inflammatory cytokines exacerbation. However, available data are not sufficient for its routine integration in clinical practice, and larger and replicated randomized control studies are needed.

Chronic mild stress and antidepressant treatment alter 5-HT1A receptor expression by modifying DNA methylation of a conserved Sp4 site

The serotonin 1A receptor (5-HT1A), a critical regulator of the brain serotonergic tone, is implicated in major depressive disorder (MDD) where it is often found to be dys-regulated. However, the extent to which stress and antidepressant treatment impact 5-HT1A expression in adults remains unclear. To address this issue, we subjected adult male BALB/c mice to unpredictable chronic mild stress (UCMS) to induce a depression-like phenotype that was reversed by chronic treatment with the antidepressant imipramine. In prefrontal cortex (PFC) and midbrain tissue, UCMS increased 5-HT1A RNA and protein levels, changes that are expected to decrease the brain serotonergic activity. The stress-induced increase in 5-HT1A expression was paralleled by a specific increase in DNA methylation of the conserved -681 CpG promoter site, located within a Sp1-like element. We show that the -681 CpG site is recognized and repressed by Sp4, the predominant neuronal Sp1-like factor and that Sp4-induced repression is attenuated by DNA methylation, despite a stress-induced increase in PFC Sp4 levels. These results indicate that adult life stress induces DNA methylation of a conserved promoter site, antagonizing Sp4 repression to increase 5-HT1A expression. Chronic imipramine treatment fully reversed the UCMS-induced increase in methylation of the -681 CpG site in the PFC but not midbrain of stressed animals and also increased 5-HT1A expression in the PFC of control animals. Incomplete reversal by imipramine of stress-induced changes in 5-HT1A methylation and expression indicates a persistence of stress vulnerability, and that sustained reversal of behavioral impairments may require additional pathways.

Genetic and familial environmental effects on suicide attempts: a study of Danish adoptees and their biological and adoptive siblings

OBJECTIVES

Genetic factors have been found to influence the risk of suicide. It is less clear if this also applies to attempted suicide. We have investigated genetic and familial environmental factors by studying the occurrence of suicide attempts in biological and adoptive siblings of adoptees who attempted suicide compared to siblings of adoptees with no suicide attempts.

METHOD

We used a random sample of 1933 adoptees from the Danish Adoption Register, a register of non-familial adoptions of Danish children, i.e. the adoptive parents are biologically unrelated to the adoptee. Analyses were conducted on incidence rates of attempted suicide in biological and adoptive siblings given occurrence of attempted suicide in the adoptees while also taking into account psychiatric disorders. Information about suicidal attempt and history of psychiatric disorder was based on hospital admissions.

RESULTS

The rate of attempted suicide in full siblings of adoptees who attempted suicide before age 60 years was higher than in full siblings of adoptees who had not attempted suicide (incidence rate ratios (IRR)=3.45; 95% confidence interval [CI]=0.94-12.7). After adjustment for history of psychiatric admission of siblings the increased rate was statistically significant (IRR=3.88; 95% CI-1.42-10.6).

LIMITATIONS

Information on attempted suicide and psychiatric history was limited to that which involved hospitalisation.

CONCLUSIONS

Genetic factors influence risk of suicide attempts.

Genetic and familial environmental effects on suicide--an adoption study of siblings

BACKGROUND

While there is clear evidence of familial influences on suicide, the origin of these is less certain. We have investigated genetic and familial environmental factors by studying the occurrence of suicide in biological and adoptive siblings of adoptees who died by suicide compared to siblings of surviving adoptees.

METHOD

We used the Danish Adoption Register and Danish population registers to compare 221 siblings of adoptees who died by suicide with the siblings of 1,903 adoptees who did not die by suicide. All adoptions in the Danish Adoption Register are non-familial, i.e. the adoptive parents are biologically unrelated to the adoptee. Analyses were conducted on incidence rates of suicide in biological and adoptive siblings given occurrence of suicide in the adoptees while also taking into account psychiatric disorders.

RESULTS

The risk of suicide in full siblings of adoptees who died by suicide before age 60 years was significantly higher than in full siblings of adoptees who had not died by suicide (incidence rate ratios (IRR) = 5.01; 95% confidence interval [CI] = 1.28-19.6). This increase persisted after adjustment for history of psychiatric admission of siblings (IRR = 4.19; 95% CI = 1.00-17.5).

CONCLUSIONS

Genetic factors influence risk of suicide, probably independently of psychiatric disorder. This is relevant in provision of advice to families, including possible prevention of suicide.

Connecting inflammation with glutamate agonism in suicidality

The NMDA-receptor antagonist ketamine has proven efficient in reducing symptoms of suicidality, although the mechanisms explaining this effect have not been detailed in psychiatric patients. Recent evidence points towards a low-grade inflammation in brains of suicide victims. Inflammation leads to production of quinolinic acid (QUIN) and kynurenic acid (KYNA), an agonist and antagonist of the glutamatergic N-methyl-D-aspartate (NMDA) receptor, respectively. We here measured QUIN and KYNA in the cerebrospinal fluid (CSF) of 64 medication-free suicide attempters and 36 controls, using gas chromatography mass spectrometry and high-performance liquid chromatography. We assessed the patients clinically using the Suicide Intent Scale and the Montgomery-Asberg Depression Rating Scale (MADRS). We found that QUIN, but not KYNA, was significantly elevated in the CSF of suicide attempters (P<0.001). As predicted, the increase in QUIN was associated with higher levels of CSF interleukin-6. Moreover, QUIN levels correlated with the total scores on Suicide Intent Scale. There was a significant decrease of QUIN in patients who came for follow-up lumbar punctures within 6 months after the suicide attempt. In summary, we here present clinical evidence of increased QUIN in the CSF of suicide attempters. An increased QUIN/KYNA quotient speaks in favor of an overall NMDA-receptor stimulation. The correlation between QUIN and the Suicide Intent Scale indicates that changes in glutamatergic neurotransmission could be specifically linked to suicidality. Our findings have important implications for the detection and specific treatment of suicidal patients, and might explain the observed remedial effects of ketamine.

Associations between the angiotensin-converting enzyme insertion/deletion polymorphism and monoamine metabolite concentrations in cerebrospinal fluid

Angiotensin II has been suggested to influence central dopamine and serotonin turnover. Since the angiotensin-converting enzyme (ACE) plays a key role in angiotensin regulation by converting inactive angiotensin I to active angiotensin II, we hypothesised that the functional insertion/deletion (I/D) polymorphism in the ACE gene, which has previously been suggested to be associated with, depression and panic disorder, may influence monoamine activity. A well-established technique for assessing brain monoamine turnover in humans is to measure concentrations of monoamine metabolites in the cerebrospinal fluid (CSF). We thus investigated possible associations between the ACE I/D polymorphism and CSF monoamine metabolite concentrations in a population of healthy male subjects. After having found such an association between the ACE I/D polymorphism and CSF levels of the dopamine metabolite homovanillic acid and the serotonin metabolite 5-hydroxyindoleacetic acid in this sample, I carriers displaying lower levels, we tried to replicate this observation in a population of violent male offenders from which also both CSF and DNA were available. Also in this sample, the same associations were found. Our results suggest that the ACE I/D polymorphism may play a role in the modulation of serotonergic and dopaminergic turnover in men.

Inferring candidate genes for attention deficit hyperactivity disorder (ADHD) assessed by the World Health Organization Adult ADHD Self-Report Scale (ASRS)

The present study tests the psychometric properties and validity of the German version of the World Health Organization Adult Attention Deficit Hyperactivity Disorder (ADHD) Self-Report Scale (ASRS), which is a short screening instrument for use in the general population. Furthermore, two candidate genes for ADHD, the COMT VAL158MET and the 5-HT2a T102C polymorphisms, were tested for associations with the ASRS subscales inattention and hyperactivity/impulsivity in N = 203 healthy subjects. The ordinal CFA yielded a two-factorial model corroborating the structure of the official English WHO version. Genetic analysis revealed an association between the VAL allele of COMT and the inattention scale (F(1, 201) = 7.20, p = 0.008), the hyperactivity/impulsivity scale (F(1, 201) = 4.30, p = 0.039), and the total ASRS scale (F(2, 201) = 7.64, p = 0.006) with highest scores in carriers of the MET/MET genotype. The C-allele of 5-HT2a was significantly associated with the hyperactivity/impulsivity scale (F(1, 201) = 5.52, p = 0.020) and the total ASRS scale (F(1, 201) = 4.21, p = 0.042) with highest scores in carriers of the TT genotype. The data provide evidence for the structural as well as for the external validity of the ASRS.

Pleiotropic effect of the TPH A779C polymorphism on nicotine dependence and personality

Recent studies from molecular genetics have suggested an association between the tryptophan hydroxylase 1 (TPH1) gene and nicotine addiction indicating a dysfunction of the serotonergic (5-HT) system in smoking behavior. In a sample of 252 healthy subjects, a significant association between variations observed in nicotine dependence and the heterozygous AC-genotype of the TPH A779C polymorphism could be demonstrated. Moreover, the heterozygous genotype was significantly associated with a personality trait of neurotic aggression (indirect hostility, negativism), as measured by the Buss-Durkee-Hostility-Inventory (BDHI). The positive heterosis effects with respect to nicotine addiction and personality support the idea that the TPH1 gene exerts pleiotropic effects.

Sleep disturbance and nonmalignant chronic pain: a comprehensive review of the literature

Sleep disturbance is an important clinical complaint for individuals with nonmalignant pain conditions. This review is a broad introduction to the literature on sleep disturbance and chronic pain conditions. The article critically reviews studies of sleep disturbance in musculoskeletal pain, arthritis, headache, and fibromyalgia. Current neurobiological hypotheses regarding the pathogenesis of sleep disturbance and chronic pain, common comorbid disorders, and pharmacologic and non-pharmacologic treatments for sleep disturbance are reviewed.

Flattening the corticosterone rhythm attenuates 5-HT1A autoreceptor function in the rat: relevance for depression

Depression is associated with glucocorticoid abnormalities, in particular a flattening of the diurnal cortisol rhythm. Recent data suggest that an important factor in the aetiology of depression may be a deficit in the function and expression of 5-HT(1A) receptors, which has been reported in depressed patients. The present study assessed the possibility that this cortisol abnormality is causal in the 5-HT(1A) receptor deficits. First, a rat model of flattened glucocorticoid rhythm was developed. Controlled release corticosterone pellets implanted for 14 days flattened the corticosterone rhythm and maintained levels constant midway between the nadir and zenith levels observed in sham-operated rats. Secondly, using microdialysis to assess 5-HT release in the hippocampus, the inhibitory response to 8-OHDPAT was measured to determine the sensitivity of somatodendritic 5-HT(1A) autoreceptors. Corticosterone treatment was found to induce a significant attenuation in the response to 8-OHDPAT, indicating functional desensitization of somatodendritic 5-HT(1A) autoreceptors. There was no effect of corticosterone treatment on basal extracellular 5-HT levels. The data suggest that the glucocorticoid abnormalities associated with depression may impact on the functioning of 5-HT(1A) receptors in the brain. These findings suggest that resolution of cortisol abnormalities may be a valuable target for pharmacotherapy in the treatment of depression.

Serotonergic function and suicidal behavior in schizophrenia

Recent studies suggest that altered serotonergic (5-HT) function, as assessed by lower prolactin (PRL) response to fenfluramine (FEN), a specific 5-HT releaser and uptake inhibitor, is associated with suicidal behavior in either depressed and personality disordered patients. The purpose of this study was to investigate, in schizophrenic patients, the relationship between suicidal behavior and PRL response to D-fenfluramine (D-FEN). A D-FEN test was performed in 18 healthy controls and 33 drug-free DSM-IV schizophrenic patients (12 with a history of suicide attempts, 21 without it). Schizophrenic patients with a history of suicide attempts showed a lower PRL response to D-FEN (Delta PRL) compared to schizophrenic patients without such history (P<0.04) and also compared to healthy controls (P<0.0003). Delta PRL did not differentiate schizophrenic patients without suicide attempts and controls. These findings could not be explained by PRL basal hormonal levels, age, sex, menstrual status, demographic or clinical characteristics. These results suggest that PRL response to D-FEN is a marker of suicidal tendencies also in schizophrenia, supporting the hypothesis that a dysfunction in serotonergic function is associated with suicidal behavior regardless of the psychiatric diagnosis.

Lack of effect of HPA axis hyperactivity on hormonal responses to d-fenfluramine in major depressed patients: implications for pathogenesis of suicidal behaviour

There is evidence for inhibitory effects of adrenocorticosteroids on serotonergic (5-HT) activity. However, in depression the relationship between altered cortisol levels and brain 5-HT function remains to be clarified. The aim of this study was to investigate whether hypothalamic-pituitary-adrenal (HPA) axis hyperactivity is associated with 5-HT dysfunction in depressed patients, especially in those with suicidal behaviour. Cortisol levels following the dexamethasone suppression test (DST, 1 mg PO) and prolactin, corticotropin and cortisol responses to the d-fenfluramine test (d-FEN, 45 mg PO) - a specific 5-HT releaser/uptake inhibitor - were measured in 71 drug-free DSM-IV major depressed inpatients (40 with a history of suicide attempt, 31 without) and 34 hospitalized healthy control subjects. Depressed patients showed higher post-DST cortisol levels but similar responses to d-FEN compared with control subjects. Hormonal responses to d-FEN were not correlated with cortisol levels (basal or post-DST). Among the depressed patients, DST suppressors and DST nonsuppressors exhibited no significant difference in endocrine responses to d-FEN. However, patients with a history of suicide attempt, when compared with patients without such a history, showed lower hormonal responses to d-FEN but comparable basal and post-DST cortisol levels. Taken together these results suggest that, in depression, HPA axis hyperactivity is not responsible for the reduced 5-HT activity found in patients with a history of suicidal behavior.

Prolactin response to D-fenfluramine and suicidal behavior in depressed patients

Previous studies of the prolactin response to D-fenfluramine in depressed patients have yielded inconsistent results. This may be because they did not address the question of suicidality. We carried out this study to test the hypothesis that lower prolactin response to D-fenfluramine is more closely associated with suicidal behavior than with depression itself. A D-fenfluramine test was performed in a sample of 18 healthy control subjects and in 85 drug-free inpatients with a DSM-III-R diagnosis of major depressive episode (49 with a history of suicide attempt, 36 without). Depressed inpatients with a history of suicide attempt showed a significantly lower prolactin response to D-fenfluramine compared to depressed inpatients without such a history and compared to control subjects. Healthy control subjects and depressed inpatients without a history of suicide attempt showed comparable levels of prolactin after D-fenfluramine. Time elapsed since suicide attempt did not influence prolactin level (baseline or post-stimulation). Results show that in our depressed drug-free inpatient sample, prolactin response to D-fenfluramine seems to be a marker of suicidality, but not of depression itself. We suggest that it is a trait marker of suicidality.

Cerebrospinal fluid amines and higher-lethality suicide attempts in depressed inpatients

Previous studies have found that not all suicide attempters with major depression have reduced serotonergic activity based on low cerebrospinal fluid 5-hydroxyindoleacetic acid (CSF- 5-HIAA) levels. In this study we hypothesized that serotonergic function is lower in depressed patients who have carried out high-lethality suicide attempts resulting in more medical damage, which might explain differences in serotonergic activity among depressed suicide attempters. We assessed the relationship of CSF 5-HIAA and other amine metabolites to the most lethal lifetime suicide attempt in 22 drug-free inpatients with major depression. CSF 5-HIAA levels were lower in depressed patients with a history of a high-lethality or well-planned suicide attempt compared to depressed patients with a history of only low-lethality suicide attempt(s). Other CSF monoamine metabolites did not correlate with suicidal behavior. Low serotonergic activity may correlate with a predisposition to more lethal suicide attempts in major depression.

Major depression and the risk of attempted suicide

We examined the risk of attempted suicide in 100 inpatients during a major depressive episode. We hypothesized that patients who attempt suicide have a vulnerability for suicidal behavior independent of severity or duration of depression, manifested by suicide attempts early in the course of a depressive episode. The first 3 months after the onset of an MDE and the first 5 years after the lifetime onset of major depressive disorder represented the highest-risk period for attempted suicide, independent of the severity or duration of depression. Familial, genetic, early-life loss experiences and comorbid alcoholism may be causal factors.

Dietary Tryptophan Ratio and Suicide in the United Kingdom, Ireland, the United States, Canada, Australia, and New Zealand

It was hypothesized that when relative dietary intake of tryptophan per capita is low compared to certain other amino acids, less serotonin is formed in brain neurons, and suicide rates tend to be high. The hypothesis was supported for males and for both sexes combined.

A longitudinal study of the relationships between psychometric test scores, offence history and the plasma concentrations of phenylacetic and 5-hydroxyindoleacetic acids in seven inmates of a prison for the psychiatrically disturbed

1. The plasma concentrations of phenylacetic (PAA) and 5-hydroxyindoleacetic (5HIAA) acids in seven inmates incarcerated in the Regional Psychiatric Centre (Prairies), Correctional Service of Canada, were assessed each weekday for four weeks (i.e., 20 samples each). Psychometric assessments for hostility, anger, depression and anxiety were also performed daily. Mean differences between subjects in psychometric and biochemical measures were subjected to tests of statistical significance. 2. The subject who was clearly most aggressive by offence history/institutional behavior scored significantly highest on scales of anger and hostility and significantly lowest with respect to PAA concentration. It was concluded that PAA may be a trait marker for aggression. 3. Plasma 5HIAA concentrations were invariant between subjects. 4. The psychometric measures were intercorrelated, thus confounding the variables of interest. They also varied little, proving insensitive to subtle mood changes.

Implications of Psychopharmacological Studies for the Practice of Psychoanalysis

Over the past 35 years psychopharmacological developments have fueled major changes in the care of psychiatric patients. The most obvious of these are in two areas: (1) the control of symptoms not heretofore consistently treated effectively, such as the benefits of lithium in bipolar disorder, and (2) the shift toward reliance on medications rather than other forms of treatment. In this article I shall cover some of the implications of the second point, but will focus principally on other, less direct consequences of the development of specific pharmacotherapies for the practice of psychoanalysis. These areas are the enhanced importance of accurate diagnosis, the expansions of categories for which drugs are helpful, and the point, or framework, from which dynamic psychotherapies have their main indications.

Biogenic amines and their metabolites in body fluids of normal, psychiatric and neurological subjects

The biogenic monoamines and their metabolites have been isolated, identified and quantified in human body fluids over the past forty years using a wide variety of chromatographic separation and detection techniques. This review summarizes the results of those studies on normal, psychiatric and neurological subjects. Tables of normal values and the methods used to obtain them should prove to be useful as a reference source for benchmark amine and metabolite concentrations and for successful analytical procedures for their chromatographic separation, detection and quantification. Summaries of the often contradictory results of the application of these methods to psychiatric and neurological problems are presented and may assist in the assessment of the validity of the results of experiments in this field. Finally, the individual, environmental and the methodological factors affecting the concentrations of the amines and their metabolites are discussed.

Serotonin and depression: old problems and new data

1. Several lines of evidence implicating some dysfunction or alteration to brain serotonergic systems in depressive states are summarized. 2. Some aspects of the interactions between the 5-HT and catecholamine pathways in the action of antidepressant drugs are examined. 3. Finally, the important role of NA modulation of serotonergic activity in the action of antidepressants is suggested.

CSF monoamine metabolites in patients and controls: support for a bimodal distribution in major affective disorders

The monoamine metabolites 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) in cerebrospinal fluid (CSF) were measured in 38 patients with major affective disorder and 48 age- and sex-matched controls by means of liquid chromatography. Statistical analysis using maximum likelihood normal mixture computations provided evidence for a subgroup of patients characterized by low CSF levels of both 5-HIAA and HVA. In controls, CSF 5-HIAA and HVA levels appeared to be normally distributed when fitted separately, whereas a subgroup of controls characterized by higher values of 5-HIAA and HVA could be discerned when metabolite data were fitted simultaneously. No relationship was found between monoamine levels and suicidal behaviour in patients. A statistically significant relationship was found between CSF 5-HIAA and HVA levels in patients and controls. These data provide supportive evidence for the existence of a subgroup of patients with an abnormal serotonin metabolism as reflected by 5-HIAA, and probably HVA, in CSF.

Biochemistry and suicidal behavior in depressed patients

The present study was undertaken in order to further explore the relationship between monoamine levels and hypothalamic-pituitary-adrenocortical (HYPAC) functioning and suicidal behavior in depressed patients. One hundred and thirty-two depressed inpatients participated in the NIMH Collaborative Study on the Psychobiology of Depression. Similar to previous reports, our suicide attempters were younger, more likely to be bipolar, had an earlier age at onset, and displayed more psychotic features. No correlation between cortisol hypersecretion or Dexamethasone Suppression Test (DST) nonsuppression and suicide attempts were found. Only the pre-DST evening plasma cortisol distinguished the groups, being lower in the attempter group. We were unable to confirm the previously reported correlation between cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA) and suicide attempts. Of the monoamines examined, only urinary and plasma 3-methoxy-4-hydroxphenylglycol (MHPG) differed between suicide attempters and nonattempters, showing lower levels in the attempter group. There was a trend for CSF MHPG in the same direction. This latter reduction was restricted to the bipolar group.

CSF monoamine metabolites in melancholia

The neurotransmitter metabolites 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and 4-hydroxy-3-methoxyphenyl glycol (HMPG) in cerebrospinal fluid (CSF) were measured by mass fragmentography in 83 patients with melancholia (diagnosed by the Newcastle Inventory and the Research Diagnostic Criteria), and 66 healthy volunteer controls. After adjustment by analysis of covariance for differences between the subject groups in body height, age and sex distribution, significantly (P less than 0.001) lower concentrations of 5-HIAA and HVA were found in the melancholia patients than in the controls. HMPG did not differ between the groups. The differences could not be accounted for by differences in timing or examination techniques, and not by previously administered drugs (all patients were drug-free at the examination, but a minority had taken small amounts of psychotropic drugs prior to the wash-out period). The differences persisted after excluding the suicidal patients. There were no clear-cut differences between unipolar and bipolar patients. It is suggested that the reduced concentrations of 5-HIAA and HVA in the melancholic patients may be due to altered serotonin and/or dopamine functions in the central nervous system, which may be connected with an increased vulnerability to certain types of affective illness.