CSF 5-hydroxyindoleacetic acid levels and suicide attempts in schizophrenia

Cerebrospinal fluid monoamine metabolite concentrations in suicide attempt: A meta-analysis

AIM

The purpose of this meta-analysis was to critically examine the data from individual studies on CSF neurotransmitter metabolites to see whether there were consistencies in the results of the comparison of suicide attempters and psychiatric controls and of the comparison of attempted suicides using violent versus nonviolent methods.

METHOD

Systematic literature search across different electronic databases using PubMed/Google Scholar/EMBASE/Cochrane library was conducted for studies that reported concentration of CSF-neurotransmitter metabolites: 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and 3-methoxy-4-hydroxy phenylglycol (MHPG) in suicide attempters, from January'1981 to November'2020. Standardized mean differences (SMDs) and corresponding 95 % confidence interval (CIs) were deduced for outcome measures. I² statistics were used to assess heterogeneity within studies. Data were analyzed using STATA software.

RESULTS

A total of 36 studies (N = 1987 attempted suicide and N = 1235 psychiatry control) were included for the meta-analysis. We found CSF levels of all the 3 metabolites i.e. 5-HIAA (SMD= -0.43; 95 %CI: -0.61, -0.24), HVA (SMD= -0.16; 95 %CI: -0.33, -0.00) and MHPG (SMD= -0.33; 95 %CI: -0.71, -0.05) were lower in suicide attempters. While the findings were consistent for 5-HIAA, they were inconsistent for the HVA and MHPG. CSF levels of 5-HIAA (SMD= -0.66; 95 %; CI: -1.01, -0.31), HVA (SMD= -0.14; 95 %CI: -0.45, 0.16) and MHPG (SMD= -0.12; 95 %CI: -0.56, 0.31) were significantly lower in violent suicide attempters than non-violent attempters. No significant publication bias found in any study.

CONCLUSION

We found a significant association between lower levels of CSF 5-HIAA in suicide attempters, particularly the violent ones, compared to psychiatric controls, whereas findings from CSF HVA and MHPG were inconsistent.

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.

The neurobiology of suicide in psychosis: A systematic review

The lifetime risk of dying by suicide in schizophrenia and related psychoses has been estimated to be approximately between 5% and 7%, though some have estimated that the number is closer to 10%. The highest risk for suicide occurs within the first year after presentation, when patients have a 12 times greater risk of dying by suicide than the general population, or a 60% higher risk compared with patients in other phases of psychosis, although the risk continues for many years. Some 31% of all deaths in first and early episode samples are due to suicide. Studies in individuals at clinical high-risk for psychosis (CHR) or with attenuated positive symptoms also demonstrate that suicidality is common and problematic in these individuals. Therefore, suicide in psychosis is a particularly severe problem. In order to develop interventions aimed at reducing the risk of suicide in psychotic individuals, it will be critical to understand the neurobiology of suicide in psychosis. In this paper, I report on the results of a systematic review of the work done to date on the neurobiology of suicide in psychosis and on suicidality in the CHR period. I will also identify gaps in knowledge and discuss future strategies for studying the neurobiology of suicidality in psychosis that may help to disentangle the links between suicide and psychosis and, by doing so, allow us to gain a greater understanding of the relationship between suicide and psychosis, which is critical for developing interventions aimed at reducing the risk of suicide in psychotic individuals.

Suicide in Schizophrenia: An Educational Overview

Suicide is an important public health problem. The most frequent psychiatric illnesses associated with suicide or severe suicide attempt are mood and psychotic disorders. The purpose of this paper is to provide an educational overview of suicidal behavior in individuals with schizophrenia. A lifetime suicide rate in individuals with schizophrenia is approximately 10%. Suicide is the largest contributor to the decreased life expectancy in individuals with schizophrenia. Demographic and psychosocial factors that increase a risk of suicide in individuals with schizophrenia include younger age, being male, being unmarried, living alone, being unemployed, being intelligent, being well-educated, good premorbid adjustment or functioning, having high personal expectations and hopes, having an understanding that life’s expectations and hopes are not likely to be met, having had recent (i.e., within past 3 months) life events, having poor work functioning, and having access to lethal means, such as firearms. Throughout the first decade of their disorder, patients with schizophrenia are at substantially elevated suicide risk, although they continue to be at elevated suicide risk during their lives with times of worsening or improvement. Having awareness of symptoms, especially, awareness of delusions, anhedonia, asociality, and blunted affect, having a negative feeling about, or non-adherence with, treatment are associated with greater suicide risk in patients with schizophrenia. Comorbid depression and a history of suicidal behavior are important contributors to suicide risk in patients with schizophrenia. The only reliable protective factor for suicide in patients with schizophrenia is provision of and compliance with comprehensive treatment. Prevention of suicidal behavior in schizophrenia should include recognizing patients at risk, delivering the best possible therapy for psychotic symptoms, and managing comorbid depression and substance misuse.

Loudness dependence of auditory evoked potentials (LDAEP) in clinical monitoring of suicidal patients with major depression: a pilot study

Loudness dependence of auditory evoked potentials (LDAEP) is a validated in vivo marker of central serotonergic function. We aimed at measuring serotonergic activity in a follow-up study of suicidal patients. It should be investigated whether suicide attempts or suicidal states cause changes in the LDAEP. Thirteen patients (mean age, 40.9 ± 11.3 years; age range, 20-61, 6 male) with a major depressive episode who had attempted suicide or had suicidal plans (Hamilton Depression Rating Scale item 3 [suicidality] ≥3) were included in the study. LDAEP and psychometric measurements took place about 2, 5, 9 and 16 days after attempted suicide or suicidal action. On day 9, LDAEP was significantly higher compared to day 2 and day 16; there was a similar tendency compared to day 5. Instability of central serotonergic function is suggested resulting in reduced serotonergic activity about 1 week after suicide attempt. Further studies are necessary that include larger samples in order to distinguish between different psychiatric diseases and to consider confounding factors like gender, smoking, medication, impulsivity or lethality of suicidal action.

CSF 5-HIAA, attempted suicide and suicide risk in schizophrenia spectrum psychosis

INTRODUCTION

There is evidence for a relationship between low levels of 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF) and suicidal behavior in mood disorder. A relationship between CSF homovanillic acid (HVA) and suicidal behavior has not been completely established. Studies done in patients with schizophrenia spectrum psychosis suffer from small numbers, short periods of follow-up and the results are contradictory. The objective of this study was to investigate the relationship between levels of CSF 5-HIAA, CSF HVA and suicidal behavior in patients with schizophrenia spectrum psychosis.

METHOD

Three hundred eighty five patients with schizophrenia spectrum psychosis admitted to the Karolinska University Hospital between 1973 and 1987 were lumbar punctured in standardized manner. Patients were followed until 2006 for a median of 26 years. Information about prior suicide attempt was retrieved from medical records and causes of death were obtained from the Causes of Death Register at the National Board of Health and Welfare.

RESULTS

At the end of the follow-up 26 patients (6.8%) had died by suicide. Male gender (OR=3.5) and attempted suicide (OR=12.4) were risk factor for suicide when combined. There were no significant correlations between levels of CSF 5-HIAA, CSF HVA, HVA/5-HIAA ratio and attempted, violent or non-violent suicide.

CONCLUSION

Male schizophrenia spectrum psychosis patients with prior suicide attempt are at high risk for suicide. No correlation between CSF monoamine metabolites levels and suicidal behavior was found. Suicidal behavior in schizophrenia spectrum psychosis may not, in contrast to mood disorders, be predicted by levels of CSF 5-HIAA and HVA.

Suicidality, impulsivity and aggression--is there a link to 5HIAA concentration in the cerebrospinal fluid?

In biological suicide research, low cerebrospinal fluid-5-hydroxyindolacetic acid (CSF-5HIAA) concentrations have been associated with suicidality, aggression and impulsivity. However, it frequently appears that the interpretation of existing study results is flawed. The analysis of various published findings suggests that contaminating factors like impulsivity or depressive symptoms in suicide attempters are often not taken into consideration at the time of suicide. The seemingly 'robust' association of low CSF-5HIAA concentration with 'suicidality' and 'aggression' is in fact rather weak. Reported associations of subgroups of suicidal behavior (e.g. violent suicide attempts) with low CSF-5HIAA concentrations are likely to represent somewhat premature translations of findings from studies that have flaws in methodology. Furthermore, the perception of 'suicidal behavior' as autoaggressive behavior or inwardly directed aggression in the view of the authors may not be useful in biological suicide research. The construct of aggressivity is insufficiently defined, resulting in difficulties to interpret empirical data. Some evidence exists, however, that reduced CSF-5HIAA concentrations might be related to certain depressive symptoms and changes in impulsivity. More carefully designed studies are required to overcome the existing methodological shortcomings.

Suicide and schizophrenia

Suicide and suicide attempts occur at a significantly greater rate in schizophrenia than in the general population. Common estimates are that 10% of people with schizophrenia will eventually have a completed suicide, and that attempts are made at two to five times that rate. Demographically associated with suicidality in schizophrenia are being young, being early in the course of the illness, being male, coming from a high socioeconomic family background, having high intelligence, having high expectations, not being married, lacking social supports, having awareness of symptoms, and being recently discharged from the hospital. Also associated are reduced self-esteem, stigma, recent loss or stress, hopelessness, isolation, treatment non-compliance and substance abuse. Clinically, the most common correlates of suicidality in schizophrenia are depressive symptoms and the depressive syndrome, although severe psychotic and panic-like symptoms may contribute as well. This review specifically explores the issue of depression in schizophrenia, in relation to suicide, by organizing the differential diagnosis of this state and highlighting their potentially treatable or correctable causes. This differential diagnosis includes both acute and chronic disappointment reactions, the prodrome of an acute psychotic episode, neuroleptic induced akinesia and akathisia, the possibility of direct neuroleptic-induced depression, negative symptoms of schizophrenia, and the possible co-occurrence of an independent depressive diathesis. The potential beneficial roles of 'atypical' antipsychotic agents, including both clozapine and more novel agents, and adjunctive treatment with other psychopharmacological medications are considered, and the important roles of psychosocial factors and interventions are recognized.

Reduced cerebrospinal HVA concentrations and HVA/5-HIAA ratios in suicide attempters. Monoamine metabolites in 120 suicide attempters and 47 controls

Dysfunctions of central monoaminergic systems are important elements of the leading biological hypotheses of suicide and depression. The purpose of the present paper was to study the levels and the relationships between the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA), the dopamine metabolite homovanillic acid (HVA) and the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) in the cerebrospinal fluid (CSF) in 120 hospitalised suicide attempters and 47 controls (healthy volunteers or patients admitted for minor surgery). The suicide attempters showed significantly lower HVA levels (174+/-82 vs. 216+/-96 nmol/L, P=0.004), HVA/5HIAA ratios (1.6+/-0.5 vs. 2.1+/-0.6, P=0.0001) and HVA/MHPG ratios (4.2+/-2.1 vs. 4.8+/-1.7, P=0.02) than the controls. The correlations between the monoamine metabolites were markedly lower in patients than in controls. CSF 5-HIAA showed no significant differences between patients and controls (107+/-40 vs. 108+/-51 nmol/L) or between violent and non-violent attempters (112+/-58 vs. 105+/-33 nmol/L). The monoamine metabolites showed no significant differences between survivors and patients who subsequently completed suicide, or between suicide attempters subgrouped by psychiatric diagnoses. The results suggest that low HVA levels and altered relationships between the monoamine metabolites are associated with suicidal behaviour.

Management of the suicidal patient with schizophrenia

No matter what the course of treatment determined to be most appropriate, suicidal behavior must be considered thoroughly, and it must be conveyed to the patient that the clinician can assist him or her through this period of increased distress. Hopelessness must be viewed as a symptom with the assumption that a more meaningful sense of purpose will emerge despite the chronic and potentially limiting nature of schizophrenia. Most people with schizophrenia are not suicidal, and most who are suicidal can be offered interventions that will reduce their symptomatology and thereby dissipate their suicidal behavior.

Assessment and intervention for the suicidal patient with schizophrenia

The risk for suicidal behavior in schizophrenia is high with 10-15% committing suicide and 20-40% making suicide attempts. Due to the chronicity and complexity of schizophrenia and the multi-determined nature of suicidal behavior, the clinician must utilize a biopsychosocial approach to assessment and intervention. Clinical factors such as psychosis, depression and substance abuse increase the risk for suicidal behavior in schizophrenia. Social factors such as social adjustment and social supports also play a critical role. Ongoing assessment and intervention of suicidal behavior, clinical symptomatology, social environment and treatment issues are essential. Prediction and prevention of suicidal behavior are not always possible however. Treatment focused on the reduction of symptomatology and maintenance of an effective social environment may attenuate the risk for suicidal behavior in schizophrenia.

The role of serotonin in schizophrenia

The hypothesis that the LSD psychosis and by inference schizophrenic psychoses are related to dysfunctions in central serotonergic systems, formulated by Woolley and Shaw in the early 1950s was the first testable theory of modern biological psychiatry. Initially, it did not get the scientific attention it deserved. First, because LSD fell into disrepute and was to all intents and purposes banned from human experimentation. Secondly, the antipsychotics were discovered in the same period, and it became clear that these compounds block dopaminergic transmission and hence for many years thereafter the dopaminergic system occupied center stage in biological schizophrenia research. Presently, interest in the relation between serotonin and schizophrenia has been revived, due to the development of serotonin-blocking agents that appear to exert therapeutic effects in schizophrenia. In this paper the evidence for and against a link between serotonergic defects and schizophrenia psychopathology is critically discussed. The conclusion to be reached is threefold. (1) Interruption of certain serotonergic circuits represents an antipsychotic principle. (2) Tentative evidence suggests the involvement of serotonergic dysfunctions in the pathogenesis of schizophrenic psychoses. (3) It is not yet known whether serotonergic lesions contribute directly to the occurrence of schizophrenic psychopathology or via alterations in the dopaminergic system.

Serotonin2 receptor binding in blood platelets of schizophrenic patients

Platelet serotonin2 (5-HT2) binding was determined in 47 neuroleptic-free schizophrenic patients and 42 normal control subjects. Although the maximum number of 5-HT2 binding sites (Bmax) was significantly higher in the blood platelets of schizophrenic patients than in those of the normal control subjects, the difference disappeared after correction for age and sex effects. However, the Bmax of schizophrenic patients who had made suicide attempts was significantly greater than that of schizophrenic patients who had not, as well as that of normal controls. There was no difference in Kd between the schizophrenic patients and control subjects, and no relation between Kd and suicide attempts. The importance of serotonin in schizophrenia and suicide attempts is discussed.

5-Hydroxyindoleacetic acid in cerebrospinal fluid and prediction of suicidal behaviour in schizophrenia

Low concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF) are associated with suicidal behaviour in patients with depressive illness, but studies of the relation between CSF 5-HIAA and suicide in schizophrenia have been inconclusive and have not included long-term follow-up. In a prospective study, we measured 5-HIAA in CSF taken from 30 schizophrenic patients in a drug-free state, and followed these patients for 11 years. 10 patients made suicide attempts during follow-up. Suicide attempters had significantly lower concentrations of CSF 5-HIAA at initial evaluation than non-attempters (mean [SE] 6.7 [2.2] vs 23.6 [5.6] ng/ml, p < 0.05). Our findings provide further evidence of the relation between serotoninergic dysfunction and suicide, and suggest a role for drugs with serotoninergic effects in schizophrenia.

Factors predicting suicide in psychotic patients

Death rate and causes of death during a mean period of 5.8 years were investigated in 250 male inpatients with psychotic disorders (DSM-III). Fifty patients died during the observation period. Suicide was confirmed in 11 of these patients and could not be excluded in 7 cases, where the cause of death was reported as uncertain. Clinical and neurobiological characteristics (DST-non-suppression, CSF proteins, and monoamine metabolites) were compared in patients who committed suicide and non-suicide patients of the same age, with or without suicidal behaviour. A highly increased mortality rate was seen among the patients and the rate of suicide was more than 20 times higher than that expected in a normal population of the same age. The estimated annual incidence of suicide was 2.5%, 1.3%, 1.0% and 0.4% for patients with bipolar disorder, paranoid psychosis, major depression and schizophrenic disorder, respectively. The following factors were significantly positively correlated with completed suicide: depressive mood, elated mood, paranoid ideas, and paternal age. All suicides had previously shown suicidal behaviour and the suicide occurred during or shortly after a period of hospitalisation. No correlations were found with age at onset of illness, duration of illness, substance abuse or neurobiological parameters.