Lower cerebrospinal fluid homovanillic acid levels in depressed suicide attempters

Clinical features of individuals with schizotypal personality disorder with and without suicidal ideation

This study compared demographic and clinical features in a sample of 384 participants: healthy controls (HC; n = 166) and individuals with schizotypal personality disorder (SPD) with (n = 50) and without (n = 168) suicidal ideation (SI) to examine specific risk factors for suicidality in SPD. Compared to the non-SI group, the SI group showed significantly greater severity of depression, aggression, impulsivity, affective lability, schizotypal features, poorer social adjustment, and had fewer social contacts. Individuals in the SI group were also more likely to have a history of a suicide attempt and comorbid borderline personality disorder in comparison to the non-SI group. Logistic regression analysis indicated that severity of depression and the number of social contacts drove the difference between the SI and non-SI groups. Compared with both SPD subgroups, the HC group was significantly less depressed, aggressive, impulsive, affectively labile, had fewer schizotypal features, was better socially adjusted, and had more social contacts. This study indicates that overall, the SI group is a more severely impaired group of individuals with SPD compared to the non-SI group. Better educating medical professionals about the diagnosis and management of SPD and its associations with suicidality is warranted.

Brain-derived neurotrophic factor in war veterans with or without a history of suicide attempt

BACKGROUND

Brain-derived neurotrophic factor (BDNF) plays a central role in brain development and plasticity and has been demonstrated to be altered in neuropsychiatric diseases and suicidal behavior. We examined whether there is a difference with regard to plasma BDNF levels between veterans who made or did not make a suicide attempt post-deployment.

METHODS

Combat veterans who made or did not make post-deployment suicide attempts were interviewed using Mini-International Neuropsychiatric Interview, the Montgomery-Åsberg Depression Rating Scale, the Barratt Impulsivity Scale (BIS) and the Scale for Suicidal Ideation (SSI). Reaction to the most recent suicide attempt was evaluated using item 16 of the Suicide Intent Scale. Plasma BDNF levels were determined by the BDNF ELISA kit.

RESULTS

Controlling for age and body-mass index (BMI), BDNF levels were higher among suicide attempters than non-attempters. We observed a positive correlation between BDNF levels and SSI scores among non-attempters but not among attempters. BDNF levels positively correlated with BIS scores among suicide attempters but not among non-attempters. Suicide attempters who regretted that they made a suicide attempt had significantly higher BDNF levels in comparison to attempters who did not regret their attempts, controlling or not controlling for age and BMI.

LIMITATIONS

A modest sample size is a shortcoming of our study.

CONCLUSIONS

Our study demonstrates that BDNF may be involved in the pathophysiology of suicidal behavior in combat veterans. Given the relative ease of measuring plasma BDNF levels, it may be appropriate to consider adding such assessments to studies of suicidal behavior.

Cerebrospinal Fluid Biomarkers in Patients With Unipolar Depression Compared With Healthy Control Individuals: A Systematic Review and Meta-analysis

IMPORTANCE

Depression has been associated with alterations in neurotransmitters, hormones, and inflammatory and neurodegenerative biomarkers, and biomarkers quantified in the cerebrospinal fluid (CSF) are more likely to reflect ongoing biochemical changes within the brain. However, a comprehensive overview of CSF biomarkers is lacking and could contribute to the pathophysiological understanding of depression.

OBJECTIVE

To investigate differences in quantified CSF biomarkers in patients with unipolar depression compared with healthy control individuals.

DATA SOURCES

PubMed, EMBASE, PsycINFO, Cochrane Library, Web of Science, and ClinicalTrials.gov were searched for eligible trials from database inception to August 25, 2021.

STUDY SELECTION

All studies investigating CSF biomarkers in individuals 18 years and older with unipolar depression and healthy control individuals were included. One author screened titles and abstracts, and 2 independent reviewers examined full-text reports. Studies that did not include healthy control individuals or included control individuals with recent hospital contacts or admissions that might affect CSF biomarker concentrations were excluded.

DATA EXTRACTION AND SYNTHESIS

Data extraction and quality assessment were performed by 2 reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines. Meta-analyses were performed using standardized mean differences (SMDs) calculated with random-effects models. A third investigator was consulted if the 2 reviewers reached different decisions or when in doubt.

MAIN OUTCOMES AND MEASURES

Quantifiable CSF biomarkers.

RESULTS

A total of 167 studies met eligibility criteria, and 97 had available data and were included in the meta-analysis. These 97 studies comprised 165 biomarkers, 42 of which were quantified in 2 or more studies. CSF levels of interleukin 6 (7 studies; SMD, 0.35; 95% CI, 0.12 to 0.59; I2 = 16%), total protein (5 studies; SMD, 0.53; 95% CI, 0.35 to 0.72; I2 = 0%), and cortisol (2 studies; SMD, 1.23; 95% CI, 0.89 to 1.57; I2 = 0%) were higher in patients with unipolar depression compared with healthy control individuals, whereas homovanillic acid (17 studies; SMD, -0.26; 95% CI, -0.39 to -0.14; I2 = 11%), γ-aminobutyric acid (4 studies; SMD, -0.50; 95% CI, -0.92 to -0.08; I2 = 55%), somatostatin (5 studies; SMD, -1.49; 95% CI, -2.53 to -0.45; I2 = 91%), brain-derived neurotrophic factor (3 studies; SMD, -0.58; 95% CI, -0.97 to -0.19; I2 = 0%), amyloid-β 40 (3 studies; SMD, -0.80; 95% CI, -1.14 to -0.46; I2 = 0%), and transthyretin (2 studies; SMD, -0.82; 95% CI, -1.37 to -0.27; I2 = 0%) were lower. The remaining 33 biomarkers had nonsignificant results.

CONCLUSIONS AND RELEVANCE

The findings of this systematic review and meta-analysis point toward a dysregulated dopaminergic system, a compromised inhibitory system, hypothalamic-pituitary-adrenal axis hyperactivity, increased neuroinflammation and blood-brain barrier permeability, and impaired neuroplasticity as important factors in depression pathophysiology.

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.

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.

SLC6A3 (DAT1) as a Novel Candidate Biomarker Gene for Suicidal Behavior

It has been previously shown that the serotonin and dopamine neurotransmitter systems might influence the predisposition to suicidal behavior. This study aims to estimate the contribution of 11 polymorphisms in the genes SLC6A4 (5HTT), HTR1A, HTR2A, HTR1B, SLC6A3 (DAT1), DRD4, DRD2, COMT, and BDNF to suicidal behavior and severity of symptoms of depression and anxiety in the Russian population. The study was performed on 100 patients with repeated suicide attempts and 154 controls. We first found an association between SLC6A3 (DAT1) 40 bp VNTR locus and suicidal behavior. This association was significant; when using the codominant (p = 0.006), dominant (p = 0.001), overdominant (p = 0.004), and log-additive (p = 0.004) models, LL genotype played a protective role (OR = 0.48, 0.29–0.82, p = 0.005). Difference in the distribution of COMT rs4680 genotypes was significant in the codominant (p = 0.04), dominant (p = 0.013), and log-additive (p = 0.02) models, and AA genotype might protect against suicide (OR = 0.49, 0.26–0.91, p = 0.025). SLC6A4 5-HTTLPR + rs25531 locus was significant in the recessive model (p = 0.024), and also affected the severity of symptoms of depression (p = 0.044) and personal anxiety (p = 0.029). Our results suggest that allelic variants of SLC6A3, COMT, and SLC6A4 genes might be considered as risk factors for suicidal attempts.

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.

Sex and race differences of cerebrospinal fluid metabolites in healthy individuals

INTRODUCTION

Analyses of cerebrospinal fluid (CSF) metabolites in large, healthy samples have been limited and potential demographic moderators of brain metabolism are largely unknown.

OBJECTIVE

Our objective in this study was to examine sex and race differences in 33 CSF metabolites within a sample of 129 healthy individuals (37 African American women, 29 white women, 38 African American men, and 25 white men).

METHODS

CSF metabolites were measured with a targeted electrochemistry-based metabolomics platform. Sex and race differences were quantified with both univariate and multivariate analyses. Type I error was controlled for by using a Bonferroni adjustment (0.05/33 = .0015).

RESULTS

Multivariate Canonical Variate Analysis (CVA) of the 33 metabolites showed correct classification of sex at an average rate of 80.6% and correct classification of race at an average rate of 88.4%. Univariate analyses revealed that men had significantly higher concentrations of cysteine (p < 0.0001), uric acid (p < 0.0001), and N-acetylserotonin (p = 0.049), while women had significantly higher concentrations of 5-hydroxyindoleacetic acid (5-HIAA) (p = 0.001). African American participants had significantly higher concentrations of 3-hydroxykynurenine (p = 0.018), while white participants had significantly higher concentrations of kynurenine (p < 0.0001), indoleacetic acid (p < 0.0001), xanthine (p = 0.001), alpha-tocopherol (p = 0.007), cysteine (p = 0.029), melatonin (p = 0.036), and 7-methylxanthine (p = 0.037). After the Bonferroni adjustment, the effects for cysteine, uric acid, and 5-HIAA were still significant from the analysis of sex differences and kynurenine and indoleacetic acid were still significant from the analysis of race differences.

CONCLUSION

Several of the metabolites assayed in this study have been associated with mental health disorders and neurological diseases. Our data provide some novel information regarding normal variations by sex and race in CSF metabolite levels within the tryptophan, tyrosine and purine pathways, which may help to enhance our understanding of mechanisms underlying sex and race differences and potentially prove useful in the future treatment of disease.

Neuropeptide Y plasma levels and suicidal behavior in combat veterans

War veterans are at increased risk of suicide that may be related to deployment and/or post-deployment stressors and to adjustment-related factors. The aim of this study was to examine whether levels of plasma neuropeptide Y (NPY) might distinguish combat veterans who have made a post-deployment suicide attempt from those who have never made a suicide attempt. We focused on NPY because of prior findings linking NPY with the neurobiology of resilience, stress-related and other disorders, and suicidal behavior. Demographic and clinical parameters of suicide attempters and non-attempters were assessed and plasma NPY was determined by radioimmunoassay. NPY levels were higher among attempters in comparison to non-attempters, controlling for sex and body-mass index. Suicide attempters had higher Scale for Suicidal Ideation (SSI) scores than non-attempters. There was a positive correlation between NPY levels and SSI scores among non-attempters but not among attempters. Likewise, NPY levels positively correlated with Brown-Goodwin Aggression Scale scores among suicide attempters but not among non-attempters. This is the first demonstration of altered plasma NPY levels in association with suicide attempt history and suicidal ideation in veterans. Our findings suggest that clinical differences between combat veterans with or without a history of suicide attempt may have a neurobiological origin.

Endogenous cannabinoid levels and suicidality in combat veterans

Combat veterans are at elevated suicide risk. The goal of this study was to test the hypothesis that combat veterans who have made a suicide attempt post-deployment can be distinguished from combat veterans who have never made a suicide attempt based on differences in psychological and biological variables. For the latter, we focused on endogenous cannabinoids, neuroendocrine markers that are associated with stress. Demographic and clinical parameters of suicide attempters and non-attempters were assessed. Blood samples were assayed for anandamide (AEA), 2-arachidonoylglycerol (2-AG), and cortisol. Suicide attempters had higher Scale for Suicidal Ideation (SSI) scores in comparison to non-attempters. Controlling for gender, 2-AG levels were higher among suicide attempters in comparison to non-attempters. Cortisol levels positively correlated with 2-AG levels and negatively correlated with SSI scores among non-attempters but not among attempters. AEA levels negatively correlated with SSI scores among attempters but not among non-attempters. Our results indicate that there are psychological and biological differences between combat veterans with or without a history of suicidal attempt. Our findings also suggest that clinically observed differences between the groups may have a neurobiological basis.

Reveals of New Candidate Active Components in Hemerocallis Radix and Its Anti-Depression Action of Mechanism Based on Network Pharmacology Approach

The global depression population is showing a significant increase. Hemerocallis fulva L. is a common Traditional Chinese Medicine (TCM). Its flower buds are known to have ability to clear away heat and dampness, detoxify, and relieve depression. Ancient TCM literature shows that its roots have a beneficial effect in calming the spirit and even the temper in order to reduce the feeling of melancholy. Therefore, it is inferred that the root of Hemerocallis fulva L. can be used as a therapeutic medicine for depression. This study aims to uncover the pharmacological mechanism of the antidepressant effect of Hemerocallis Radix (HR) through network pharmacology method. During the analysis, 11 active components were obtained and screened using ADME—absorption, distribution, metabolism, and excretion— method. Furthermore, 267 HR targets and 740 depressive disorder (DD) targets were gathered from various databases. Then protein–protein interaction (PPI) network of HR and DD targets were constructed and cluster analysis was applied to further explore the connection between the targets. In addition, gene ontology (GO) enrichment and pathway analysis was applied to further verify that the biological process related to the target protein is associated with the occurrence of depression disorder. In conclusion, the most important bioactive components—anthraquinone, kaempferol, and vanillic acid—can alleviate depression symptoms by regulating MAOA, MAOB, and ESR1. The proposed network pharmacology strategy provides an integrating method to explore the therapeutic mechanism of multi-component drugs on a systematic level.

Prevalence of suicide attempt in individuals with major depressive disorder: a meta-analysis of observational surveys

BACKGROUND

Suicide attempt (SA), which is one of the strongest predictors of completed suicide, is common in major depressive disorder (MDD) but its prevalence across epidemiological studies has been mixed. The aim of this comprehensive meta-analysis was to examine the pooled prevalence of SA in individuals with MDD.

METHODS

A systematic literature search was conducted in PubMed, Embase, PsycINFO, Web of Science and Cochrane Library from their commencement date until 27 December 2017. Original studies containing data on prevalence of SA in individuals with MDD were analyzed.

RESULTS

In all, 65 studies with a total of 27 340 individuals with MDD were included. Using the random effects model, the pooled lifetime prevalence of SA was 31% [95% confidence interval (CI) 27-34%], 1-year prevalence was 8% (95% CI 3-14%) and 1-month prevalence was 24% (95% CI 15-34%). Subgroup analyses revealed that the lifetime prevalence of SA was significantly associated with the patient setting, study region and income level, while the 1-month prevalence of SA was associated with only the patient setting.

CONCLUSION

This meta-analysis confirmed that SA was common in individuals with MDD across the world. Careful screening and appropriate interventions should be implemented for SA in the MDD population.

Poor evidence for putative abnormalities in cerebrospinal fluid neurotransmitters in patients with depression versus healthy non-psychiatric individuals: A systematic review and meta-analyses of 23 studies

BACKGROUND

Although investigated for decades, surprisingly no systematic review has ever been published on monoamines concentrations in cerebrospinal fluid (CSF) in major depressive disorder (MDD) versus healthy individuals (HC).

METHODS

We did a systematic review and meta-analyses according to the PRISMA Statement based on comprehensive database searches for studies on CSF biomarkers of monoamines and their precursor and/or metabolites, and glutamine, glutamate and GABA in MDD versus HC. Risk of bias was systematically assessed.

RESULTS

A total of 23 studies were included. Statistically significantly decreased levels between MDD and HC were found regarding CSF 5-HIAA (n = 2/13 (15%)), HVA (n = 2/11 (18%)), MHPG (n = 1/8 (13%)), and GABA (n = 2/4 (50%)), while increased levels were reported regarding NE (n = 1/2 (50%)), MHPG (n = 1/8 (13%)) and DOPEG (n = 1/1 (100%)). A majority of the studies found no statistically significant differences between MDD and HC regarding CSF 5-HIAA, HVA, NE, MHPG, glutamine, glutamate and GABA. Meta-analyses showed: 5-HIAA (-3.85, -8.89, 1.19, 0.14), HVA (-18.02, -30.99, -5.04, 0.01), MHPG (0.11, -2.96, 3.17, 0.95) and GABA (-33.20, -51.79, -14.62, 0.00) (mean difference, lower 95% CL, upper 95% CL, p-value). Most studies were influenced by risk of bias mainly due to small sample sizes, and not considering potential confounders as age, gender, severity of depression, body height and position during lumbar puncture, analytics of biomarkers and medication.

CONCLUSION

The evidence for CSF 5-HIAA, HVA, NE, MHPG, DOPEG and GABA being related to the pathophysiology of MDD is poor. Future controlled studies of monoamines or metabolites should validate the null i.e., that the concentrations of these compounds are not abnormal in MDD.

Cerebrospinal fluid monoamine metabolite concentrations in depressive disorder: A meta-analysis of historic evidence

Altered monoaminergic functions have been implicated in the pathophysiology of depressive disorder. However, previously reported cerebrospinal fluid (CSF) monoamine metabolite concentrations in major depression have been inconsistent. We performed a meta-analysis of historic evidence to determine whether CSF monoamine metabolite levels were different between patients with depression and normal controls, and could be used as depression biomarkers. Relevant studies that investigated CSF 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) levels in patients with depression and normal controls were identified in PubMed, Web of Science, PsycINFO, and Embase databases through September 5, 2017, using a synonymous search for depression, CSF, normal, control, and each monoamine metabolite name, and in the reference lists of the acquired articles. Obtained records were individually scrutinized for eligibility. Our search strategy identified 26 studies, including our own. We employed random effects modeling and adopted "Hedges's g" as an index of effect size. In the meta-analyses, no significant difference was observed in CSF 5-HIAA or MHPG levels between patients with depressive disorder and controls. In contrast, CSF HVA was significantly decreased in patients with depression (Hedges's g = -0.30, P = 0.0000025), and these results remained significant after patients with bipolar disorder were excluded (Hedges's g = -0.37, P = 0.000061). In the meta-regression, sex was significantly associated with the Hedges's g of CSF HVA (Q = 4.41, P = 0.036). This meta-analysis revealed that only CSF HVA, and not 5-HIAA or MHPG, levels were decreased in depressive disorder. The reduction in the CSF HVA concentration in patients with depression may guide future studies on depression and serve as a useful biomarker of depressive disorder.

Dehydroepiandrosterone and dehydroepiandrosterone sulfate levels in combat veterans with or without a history of suicide attempt

OBJECTIVE

The goal of this study was to determine whether combat veterans who have made a suicide attempt postdeployment can be distinguished from combat veterans who have never made a suicide attempt based on differences in psychological and biological variables.

METHODS

Demographic and clinical parameters of suicide attempters and non-attempters were assessed. Blood samples were assayed for dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS).

RESULTS

Suicide attempters had higher Scale for Suicidal Ideation and Montgomery-Åsberg Depression Rating Scale (MADRS)-suicidal thoughts item scores in comparison with non-attempters. There was a trend toward higher MADRS scores in the suicide attempter group compared with non-attempters. Suicide attempters had significantly lower levels of DHEA and DHEAS compared with non-attempters. Scale for Suicidal Ideation scores in all study participants combined negatively correlate with DHEA and DHEAS levels. DHEAS levels negatively correlate with Scale for Suicidal Ideation scores in suicide non-attempters but not in suicide attempters. DHEA/DHEAS ratios positively correlate with total adolescence aggression scores, total adulthood aggression scores, and total aggression scale scores in suicide attempters but not in suicide non-attempters.

CONCLUSION

There are psychobiological differences between combat veterans with or without a history of suicidal behaviour.

Antidepressant-like deliverables from the sea: evidence on the efficacy of three different brown seaweeds via involvement of monoaminergic system

Brown seaweeds exhibit several health benefits in treating and managing wide array of ailments. In this study, the antidepressant-like effect of methaolic extracts from Sargassum swartzii (SS), Stoechospermum marginatum (SM), and Nizamuddinia zanardinii (NZ) was examined in forced swimming test (FST), in rats. Oral administration of SS, SM, and NZ extract (30-60 mg/kg) exhibited antidepressant-like activity in FST by reducing immobility time as compared to control group, without inducing significant change in ambulatory behavior in open field test. In order to evaluate the involvement of monoaminergic system, rats were pretreated with the inhibitor of brain serotonin stores p-chlorophenylalanin (PCPA), dopamine (SCH23390 and sulpiride), and adrenoceptor (prazosin and propranolol) antagonists. Rats receiving treatment for 28 days were decapitated and brains were analyzed for monoamine levels. It may be concluded that the extracts of SS, SM, and NZ produces antidepressant-like activity via modulation of brain monoaminergic system in a rat model.

Suicide among Animals: A Review of Evidence

Naturalists have not identified suicide in nonhuman species in field situations, despite intensive study of thousands of animal species. In this review, evidence on suicidal behavior among animals is analyzed to discover analogies with human suicidal behavior. Literature was retrieved by exploring Medline/PubMed and PsychINFO databases (1967–2007) and through manual literature searches. Keyword terms were “suicide or suicidal behavior” and “animal or animal behavior.” Few empirical investigations have been carried out on this topic. Nevertheless, sparse evidence supports some resemblance between the self-endangering behavior observed in the animal kingdom, particularly in animals held in captivity or put under pressure by environmental challenges, and suicidal behavior among humans. Animal models have contributed to the study of both normal and pathological human behaviors: discovering some correlates of suicide among animals could be a valid contribution to the field.

Involvement of monoaminergic system in the antidepressant-like effect of (octylseleno)-xylofuranoside in the mouse tail suspension test

Depression is one of the most commonly diagnosed neuropsychiatric disorders and several studies have demonstrated a role for selenium in mood disorders. For this reason, the present study investigated the role of the monoaminergic system in the antidepressant-like action of (octylseleno)-xylofuranoside (OSX), an organoselenium compound, in the tail suspension test (TST) in mice. For this purpose, OSX (0.001–10 mg/kg) was administered orally (p.o.) 30 min prior to testing, and all of the tested doses reduced the immobility time in the TST without changing the locomotor activity measured in the open field test (OFT). Furthermore, the antidepressant-like effect of OSX (0.01 mg/kg, p.o.) in the TSTwas prevented by pre-treatment in mice with ketanserin (1 mg/kg, intraperitoneal route (i.p.); a 5-HT2A/2C receptor antagonist),WAY100635 (0.1mg/kg, subcutaneous (s.c.); a selective 5-HT1A receptor antagonist), p-chlorophenylalaninemethyl ester-PCPA (100mg/kg, i.p.; a selective inhibitor of tryptophan hydroxylase), prazosin (1 mg/kg, i.p.; an α1-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p.; an α2-adrenoceptor antagonist), SCH233390 (0.05 mg/kg, s.c., a dopaminergic D1 receptor antagonist) and sulpiride (50 mg/kg, i.p., a dopaminergic D2 receptor antagonist), but not with ondansetron (1 mg/kg, i.p.; a selective 5-HT3 receptor antagonist). Taken together, these data demonstrate that OSX has a potent antidepressant like effect in TST at lower doses (0.001–10 mg/kg), which is dependent on its interaction with the serotonergic, noradrenergic and dopaminergic systems.

Risk factors for suicide among patients with schizophrenia: a cohort study focused on cerebrospinal fluid levels of homovanillic acid and 5-hydroxyindoleacetic acid

BACKGROUND

The objective of this study was to investigate the association between 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) in cerebrospinal fluid (CSF), bullying, and later suicide among patients with schizophrenia.

METHODS

Ninety-nine patients with schizophrenia were included. Correlations of clinical factors, 5-HIAA and HVA, and later suicide were investigated.

RESULTS

Twelve patients committed suicide (12%) during a 28-year follow-up period. Later suicide was correlated to bullying in childhood (P=0.02) and a lower quotient of HVA/5-HIAA in CSF (P<0.05).

CONCLUSION

Suicide in schizophrenia is related to childhood exposedness and CSF neurotransmitter levels.

Comparative analysis of self-injury in people with psychopathology or neurodevelopmental disorders

Self-injury is a complex and poorly understood behavior observed in people with psychopathology or neurodevelopmental disorders (NDD). Despite the differences in etiology and progression of these distinct disease domains, it is possible that overlapping molecular pathways underlie the expression of self-injurious behaviors (SIBs). This review outlines the similarities and differences at the behavioural and molecular level, where SIBs in both conditions may involve opioid, nucleoside, and dopamine signalling. These points of convergence have important implications for treatment and research of SIB in both populations.

The co-occurrence of aggression and self-harm: systematic literature review

BACKGROUND

Epidemiological research supports an association between aggression and self-harm through data on the frequency with which individuals exhibit both behaviours. Unbiased evidence, however, is needed to draw conclusions about the nature and extent of co-occurrence.

METHOD

Systematic review of published studies was undertaken to evaluate whether or not the frequency with which aggression and self-harm co-occur is beyond that which would be expected by chance. Outcome measures included: (a) between-group differences on a standardised aggression/self-harm measure - the groups defined by scores on a measure of the other behaviour; (b) correlations between the two behaviours; (c) co-occurrence rates in populations defined by the presence of either behaviour; (d) co-occurrence rates in populations not defined by either behaviour. Odds ratios were calculated for studies presenting complete frequency data.

RESULTS

123 studies, some yielding more than one type of result, met the inclusion criteria. Most case-control studies found elevated levels of aggression in self-harming populations (or self-harm in aggressive populations) compared to controls. The majority of correlational, co-occurrence rate, and odds ratio data found aggression and self-harm to be associated.

LIMITATIONS

Results were subject to descriptive synthesis only and thus, unable to report an overall effect size.

CONCLUSIONS

Evidence suggests that aggression and self-harm frequently co-occur. Such evidence necessitates more theoretical discussion and associated research on the source and nature of co-occurrence. Nonetheless, individuals who present with one behaviour may be considered an 'at-risk' group in terms of exhibiting the other. Such evidence holds implications for practice (e.g. risk assessment).

Catechol-O-methyltransferase Val158Met polymorphism and altered COMT gene expression in the prefrontal cortex of suicide brains

Catechol-O-methyltransferase (COMT) plays a key role in the degradation of catecholamine neurotransmitters within the brain. A functional polymorphism COMT Val158Met has been associated with psychiatric disorders including suicidal behavior. In the present study we examined whether this polymorphism was related to COMT mRNA expression in frontal cortical regions, and whether the expression of COMT differed between depressed suicide victims and psychiatric healthy controls. The Val158Met polymorphism was determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. The levels of COMT mRNA expression in the frontopolar cortex (FPC; 29 suicides vs. 27 controls) and orbital frontal cortex (OFC; 19 suicides vs. 15 controls) were significantly increased among depressed individuals that died by suicide relative to those of controls, being up-regulated by approximately 60% and 65% in the FPC and OFC, respectively. Furthermore, among individuals with the Met allele (Met/Met and Met/Val genotypes) who died by suicide COMT mRNA expression was elevated relative to that of the nondepressed Met allele carriers. However, significant differences were not detected between suicides (n=49) and controls (n=72) with respect to the Val158Met genotypic distribution and allelic frequencies. These results are consistent with the perspective that altered COMT mRNA expression in frontal cortical brain regions might contribute to suicide and/or depression, further supporting the role of dysregulation of catecholaminergic pathway genes in the pathophysiology of suicide behaviors.

Polyunsaturated fatty acid associations with dopaminergic indices in major depressive disorder

Dopaminergic function is thought to be altered in major depression and, in animal studies, is reduced in omega-3 polyunsaturated fatty acid (PUFA) deficiency states. Therefore we studied PUFAs and resting prolactin, a marker for dopaminergic tone, and cerebrospinal fluid homovanillic acid (HVA), the chief dopamine metabolite. In medication-free adults (n = 23) with DSM-IV major depressive disorder (MDD), we measured plasma phospholipid levels of omega-3 PUFAs docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the omega-6 PUFA arachidonic acid (AA), and plasma prolactin levels before and after administration of dl-fenfluramine (FEN). In a subset of patients (n = 14), cerebrospinal fluid levels of HVA and the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were obtained through lumbar puncture. Baseline prolactin was negatively correlated with omega-3 PUFAs (logDHA, F(1,21) = 20.380, p < 0.001; logEPA, F(1,21) = 10.051, p = 0.005) and positively correlated with logAA:DHA (F(1,21) = 15.263, p = 0.001), a measure of omega-6/omega-3 balance. LogDHA was negatively correlated with CSF HVA (Spearman's ρ = -0.675, p = 0.008) but not 5-HIAA (Spearman's ρ = -0.143, p = 0.626) after controlling for sex and HVA - 5-HIAA correlation. PUFAs did not predict the magnitude of the FEN-stimulated change in prolactin, considered to be a serotonin effect. The robust relationship of omega-3 PUFAs with dopaminergic but not serotonergic indices suggests that omega-6:omega-3 balance may impact depression pathophysiology through effects on the dopaminergic system.

Pain and suicidality: insights from reward and addiction neuroscience

Suicidality is exceedingly prevalent in pain patients. Although the pathophysiology of this link remains unclear, it may be potentially related to the partial congruence of physical and emotional pain systems. The latter system's role in suicide is also conspicuous during setbacks and losses sustained in the context of social attachments. Here we propose a model based on the neural pathways mediating reward and anti-reward (i.e., allostatic adjustment to recurrent activation of the reward circuitry); both are relevant etiologic factors in pain, suicide and social attachments. A comprehensive literature search on neurobiology of pain and suicidality was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) physical and emotional pain, (2) emotional pain and social attachments, (3) pain- and suicide-related alterations of the reward and anti-reward circuits as compared to addiction, which is the premier probe for dysfunction of these circuits and (4) mechanistically informed treatments of co-occurring pain and suicidality. Pain-, stress- and analgesic drugs-induced opponent and proponent states of the mesolimbic dopaminergic pathways may render reward and anti-reward systems vulnerable to sensitization, cross-sensitization and aberrant learning of contents and contexts associated with suicidal acts and behaviors. These findings suggest that pain patients exhibit alterations in the brain circuits mediating reward (depressed function) and anti-reward (sensitized function) that may affect their proclivity for suicide and support pain and suicidality classification among other "reward deficiency syndromes" and a new proposal for "enhanced anti-reward syndromes". We suggest that interventions aimed at restoring the balance between the reward and anti-reward networks in patients with chronic pain may help decreasing their suicide risk.

Selective knockout of the casein kinase 2 in d1 medium spiny neurons controls dopaminergic function

BACKGROUND

Dopamine, crucial for the regulation of motor function and reward, acts through receptors mainly expressed in striatum as well as cortex. Dysregulation of dopaminergic signaling is associated with various neuropsychiatric disorders. Consequently, dopamine-regulating drugs are effectively used in treating these disorders, such as L-DOPA for Parkinson's disease, methylphenidate for attention-deficit/hyperactivity disorder, or antipsychotics for schizophrenia. As a result, there has been much interest in dissecting signaling networks in the two morphologically indistinguishable D1- and D2-receptor-expressing medium spiny neurons. Our previous results highlighted a role for casein kinase 2 (CK2) in the modulation of dopamine D1 receptor (D1R) signaling in cells.

METHODS

To study the importance of CK2 in vivo, we have selectively knocked out CK2, in either D1- or D2-medium spiny neurons (MSNs) and characterized the mice behaviorally and biochemically (n = 4-18).

RESULTS

The D1-MSN knockout mice exhibited distinct behavioral phenotypes including novelty-induced hyperlocomotion and exploratory behavior, defective motor control, and motor learning. All of these behavioral traits are indicative of dysregulated dopamine signaling and the underlying mechanism appears to be an alteration of D1R signaling. In support of this hypothesis, D1R levels were upregulated in the knockout mice, as well as phosphorylation of DARPP-32 (dopamine- and cyclic adenosine monophosphate [cAMP]-regulated phospho-protein of 32 kDa), most of the behavioral phenotypes were abolished by the D1R antagonist, SCH23390, and the D2-MSN knockout mice displayed no obvious behavioral phenotype.

CONCLUSIONS

A single kinase, CK2, in D1-MSNs significantly alters dopamine signaling, a finding that could have therapeutic implications for disorders characterized by dopamine imbalance such as Parkinson's disease, attention-deficit/hyperactivity disorder, and schizophrenia.

Antidepressant-like effect of flavonoids extracted from Apocynum venetum leaves on brain monoamine levels and dopaminergic system

ETHNOPHARMACOLOGICAL RELEVANCE

Apocynum venetum L. (Apocynaceae), a traditional medicinal plant, has been used for the improvement of emotions in Asian countries.

AIM OF THE STUDY

We explored the antidepressant-like effect and monoaminergic mechanism of a flavonoids extract from Apocynum venetum leaves (AV-extract).

MATERIALS AND METHODS

Effect of AV-extract (25, 50 and 100 mg/kg, i.g.) on mice's immobility time was assessed in forced swim test (FST) and tail suspension test (TST). The locomotor activity was evaluated in the open-field test (OFT). Additionally, the main monoamine neurotransmitters serotonin (5-HT), noradrenaline (NA) and dopamine (DA) and their metabolites 5-hydroxyindole-3-acetic acid (5-HIAA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the mouse hippocampus involved in the antidepressant-like effect of AV-extract was also determined by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS).

RESULTS

AV-extract (50 and 100 mg/kg, i.g.) administration significantly reduced the immobility time in both the FST and TST without accompanying changes in locomotor activity in the OFT. It was also found that the AV-extract significantly increased the concentrations of the main neurotransmitters NE and DA along with their respective metabolites DOPAC, HVA in the hippocampus. The antidepressant-like effect of the AV-extract (50 mg/kg, i.g.) was prevented by the pretreatment of mice with SCH23390 (0.05 mg/kg, i.g., a dopamine D1 receptor antagonist) or sulpiride (50 mg/kg, i.g., a dopamine D2 receptor antagonist).

CONCLUSION

The AV-extract produced significant antidepressant-like effects, which likely attribute to increased NE and DA along with their respective metabolites DOPAC, HVA in the mouse hippocampus, and dependent on interaction with dopaminergic (D1 and D2 receptor) systems.

Antidepressant-like effect of creatine in mice involves dopaminergic activation

Creatine has been shown to play a significant role in health and disease. However, studies concerning its effect on mood are scarce. This study investigated the effect of creatine (p.o.) in the tail suspension test, a predictive test of antidepressant activity. Creatine reduced the immobility time in the tail suspension test (0.1-1000 mg/kg, male and female mice), without affecting locomotor activity. Furthermore, the involvement of the dopaminergic system in creatine-induced antidepressant-like effect in male mice in the tail suspension test was investigated. The anti-immobility effect of creatine (1 mg/kg) was prevented by the pre-treatment of mice with haloperidol (0.2 mg/kg, intraperitoneal (i.p.) route, non-selective dopamine receptor antagonist), (R)-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH23390; 0.05 mg/kg, subcutaneous (s.c.) route, dopamine D₁ receptor antagonist) and sulpiride (50 mg/kg, i.p., dopamine D₂ receptor antagonist). Creatine (0.01 mg/kg, sub-effective dose) in combination with sub-effective doses of (1-phenyl-7,8-dihydroxy-2,3,4,5-tetrahydro-1H-3-benzazepine) hydrochloride (SKF38393; 0.1 mg/kg, s.c., dopamine D₁ receptor agonist), apomorphine (0.5 µg/kg, i.p., preferential dopamine D₂ receptor agonist) or bupropion (1 mg/kg, p.o., dopamine reuptake inhibitor with subtle activity on noradrenergic reuptake) reduced the immobility time in the tail suspension test as compared with either drug alone. These results indicate that the antidepressant-like effect of creatine is likely mediated by an activation of dopamine D₁ and D₂ receptors.

Postpartum and depression status are associated with lower [[¹¹C]raclopride BP(ND) in reproductive-age women

The early postpartum period is associated with increased risk for affective and psychotic disorders. Because maternal dopaminergic reward system function is altered with perinatal status, dopaminergic system dysregulation may be an important mechanism of postpartum psychiatric disorders. Subjects included were non-postpartum healthy (n=13), postpartum healthy (n=13), non-postpartum unipolar depressed (n=10), non-postpartum bipolar depressed (n=7), postpartum unipolar (n=13), and postpartum bipolar depressed (n=7) women. Subjects underwent 60 min of [¹¹C]raclopride-positron emission tomography imaging to determine the nondisplaceable striatal D₂/₃ receptor binding potential (BP(ND)). Postpartum status and unipolar depression were associated with lower striatal D₂/₃ receptor BP(ND) in the whole striatum (p=0.05 and p=0.02, respectively) that reached a maximum of 7-8% in anteroventral striatum for postpartum status (p=0.02). Unipolar depression showed a nonsignificant trend toward being associated with 5% lower BP(ND) in dorsal striatum (p=0.06). D₂/₃ receptor BP(ND) did not differ significantly between unipolar depressed and healthy postpartum women or between bipolar and healthy subjects; however, D₂/₃ receptor BP(ND) was higher in dorsal striatal regions in bipolar relative to unipolar depressives (p=0.02). In conclusion, lower striatal D₂/₃ receptor BP(ND) in postpartum and unipolar depressed women, primarily in ventral striatum, and higher dorsal striatal D₂/₃ receptor BP(ND) in bipolar relative to unipolar depressives reveal a potential role for the dopamine (DA) system in the physiology of these states. Further studies delineating the mechanisms underlying these differences in D₂/₃ receptor BP(ND), including study of DA system responsivity to rewarding stimuli, and increasing power to assess unipolar vs bipolar-related differences, are needed to better understand the affective role of the DA system in postpartum and depressed women.

CSF biomarkers in suicide attempters--a principal component analysis

OBJECTIVE

The objective of the present study was to identify biological patterns (factors) among 20 cerebrospinal fluid (CSF) biomarkers in suicide attempters and subsequently analyse their association with suicidal behaviour.

METHOD

We measured kynurenic acid, orexin, homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), 3-methoxy-4-hydroxyphenylglycol, chemokines, matrix metalloproteases and cytokines in the CSF of 124 drug-free suicide attempters. Patients were evaluated for suicidality and psychiatric symptoms using well-defined psychiatric rating scales and followed-up regarding future suicide. We used principal component analysis to identify factors among the biological substances.

RESULTS

Four factors were extracted from the 20 biomarkers, explaining 52.4% of the total variance. Factors 1 and 2 were characterized by high loadings of chemokines and cytokines respectively. They were both associated with severe depressive symptoms. Factor 2 was also associated with a high suicidal intent. Factor 4 was characterized by strong loadings of the monoamine metabolites 5-HIAA and HVA, as well as orexin and interleukin-6. High scores on this factor were found in patients who performed a violent suicide attempt and in patients who subsequently completed suicide.

CONCLUSION

Our results suggest that specific combinations of CSF biomarkers may discriminate between types of suicidal behaviour and indicate increased risk for future suicide.

Involvement of dopamine receptors in the antidepressant-like effect of melatonin in the tail suspension test

Melatonin was previously shown to produce an antidepressant-like effect in the tail suspension test. In this work the mechanisms underlying its antidepressant-like effect were further studied by investigating the involvement of the dopaminergic system in its antidepressant-like effect in the tail suspension test. The effect of melatonin (1mg/kg, i.p.) was prevented by the pretreatment of mice with haloperidol (0.2mg/kg, i.p., a nonselective dopaminergic receptor antagonist), SCH23390 (0.05 mg/kg, s.c., a selective dopamine D1 receptor antagonist), and sulpiride (50mg/kg, i.p., a selective dopamine D2 receptor antagonist). The i.p. administration of melatonin (0.01 mg/kg) or fluoxetine (1mg/kg, a serotonin reuptake inhibitor) in combination with SFK38393 (0.1mg/kg, s.c., a dopamine D1 receptor agonist) reduced the immobility time in the tail suspension test as compared with either drug alone. Moreover, the pretreatment with melatonin (0.01 mg/kg, i.p.) produced a synergistic effect with apomorphine (0.5 microg/kg, i.p., a dopamine D2 receptor agonist), but the pretreatment with fluoxetine (1mg/kg, i.p.) was ineffective to potentiate the effect of apomorphine. Dopamine receptor antagonists or agonists alone or in combination with melatonin did not affect locomotor activity. These results indicate that the antidepressant-like effect of melatonin in the tail suspension test is likely mediated by an interaction with the dopaminergic system, through an activation of dopamine D1 and D2 receptors. Our data confirm the previous notion on the role exerted by melatonin in depression, suggesting that it might be further investigated as an alternative for the management of depression associated with anhedonia.

Evidence for the involvement of the monoaminergic system in the antidepressant-like effect of magnesium

Literature data has shown that acute administration of magnesium reduces immobility time in the mouse forced swimming test (FST), which suggests potential antidepressant activity in humans. However, its mechanism of action is not completely understood. Thus, this study is aimed at investigating the antidepressant-like action of magnesium and the possible involvement of the monoaminergic system in its effect in the FST. The immobility time in the FST was significantly reduced by magnesium chloride administration (30-100 mg/kg, i.p.) without accompanying changes in ambulation when assessed in an open-field test. The pre-treatment of mice with NAN-190 (0.5 mg/kg, i.p. a 5-HT(1A) receptor antagonist), WAY100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist), ritanserin (4 mg/kg, i.p., a 5-HT(2A/2C) receptor antagonist), ketanserin (5 mg/kg, a preferential 5-HT(2A) receptor antagonist), prazosin (1 mg/kg, i.p., an alpha(1)-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an alpha(2)-adrenoceptor antagonist), haloperidol (0.2 mg/kg, i.p., a non selective dopaminergic receptor antagonist), SCH23390 (0.05 mg/kg, s.c., a dopamine D(1) receptor antagonist) or sulpiride (50 mg/kg, i.p., a dopamine D(2) receptor antagonist) 30 min before the administration of magnesium chloride (30 mg/kg, i.p.) significantly prevented its anti-immobility effect in the FST. Moreover, the administration of sub-effective doses of fluoxetine (10 mg/kg, i.p., serotonin reuptake inhibitor), imipramine (5 mg/kg, i.p., a mixed serotonergic noradrenergic reuptake inhibitor), bupropion (1 mg/kg, i.p., dopamine reuptake inhibitor) was able to potentiate the action of sub-effective doses of magnesium chloride. In conclusion, the present study provides evidence indicating that the antidepressant-like effect of magnesium in the FST is dependent on its interaction with the serotonergic (5-HT(1A) and 5-HT(2A/2C) receptors), noradrenergic (alpha(1)- and alpha(2)- receptors) and dopaminergic (dopamine D(1) and D(2) receptors) systems.

Cerebrospinal fluid monoamine metabolites and suicide

Prospective studies of the serotonergic system and suicide report that low 5-hydroxyindolacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) and a history of attempted suicide predict suicide risk. Low CSF homovanillic acid (HVA) is reported to be associated with past and future lethality of suicide attempts but not with suicide. The interrelationships between monoamine metabolites, violent method, suicide intent and lethality of suicidal behaviour are complex. We hypothesized that CSF 5-HIAA and HVA levels are related to suicide intent, violence and lethality of suicidal behaviour. Fifteen male suicide attempters admitted to a psychiatric ward at the Karolinska University Hospital and eight healthy male volunteers were submitted to lumbar puncture and CSF 5-HIAA and HVA were assayed. Suicide intent with the Beck Suicide Intent Scale (SIS), lethality and violence of suicidal behaviour were assessed. All patients were followed up for causes of death. Six suicides and one fatal accident were identified with death certificates. Mean CSF 5-HIAA but not CSF HVA differed between suicides and survivors. Violent suicides had higher suicide intent and CSF 5-HIAA than non-violent suicides. In violent suicides, CSF 5-HIAA levels were negatively correlated with SIS. Greater suicide intent may be associated with greater aggressive intent and predicts a violent suicide method.

Depressive Störungen

Das Spektrum depressiver Erkrankungen macht den Hauptteil affektiver Störungen aus und gehört mit einer Inzidenz von ca. 8–20% zu den häufigsten psychischen Erkrankungen. Depressionen werden nach wie vor zu selten einer adäquaten Therapie (Antidepressiva, störungsspezifische Psychotherapie wie z. B. kognitive Verhaltenstherapie) zugeführt.

Prediction and prevention of suicide in patients with unipolar depression and anxiety

Epidemiological data suggest that between 59 and 87% of suicide victims suffered from major depression while up to 15% of these patients will eventually commit suicide. Male gender, previous suicide attempt(s), comorbid mental disorders, adverse life-situations, acute psycho-social stressors etc. also constitute robust risk factors. Anxiety and minor depression present with a low to moderate increase in suicide risk but anxiety-depression comorbidity increases this risk dramatically Contrary to the traditional psychoanalytic approach which considers suicide as a retrospective murder or an aggression turned in-wards, more recent studies suggest that the motivations to commit suicide may vary and are often too obscure. Neurobiological data suggest that low brain serotonin activity might play a key role along with the tryptophan hydroxylase gene. Social factors include social support networks, religion etc. It is proven that most suicide victims had asked for professional help just before committing suicide, however they were either not diagnosed (particularly males) or the treatment they received was inappropriate or inadequate. The conclusion is that promoting suicide prevention requires the improving of training and skills of both psychiatrists and many non-psychiatrists and especially GPs in recognizing and treating depression and anxiety. A shift of focus of attention is required in primary care to detect potentially suicidal patients presenting with psychological problems. The proper use of antidepressants, after a careful diagnostic evaluation, is important and recent studies suggest that successful acute and long-term antidepressant pharmacotherapy reduces suicide morbidity and mortality.

Antidepressant-like effect of the extract from leaves of Schinus molle L. in mice: evidence for the involvement of the monoaminergic system

Schinus molle L. (Anacardiaceae), among other uses, is popularly employed for the treatment of depression. In this study, the antidepressant-like effect of the hexanic extract from leaves of S. molle was investigated in the mouse tail suspension test (TST), a predictive model of depression. The immobility time in the TST was significantly reduced by the extract (dose range 30-600 mg/kg, p.o.), without accompanying changes in ambulation when assessed in an open-field test. The efficacy of extract was found to be comparable to that of fluoxetine (10 mg/kg, p.o.). The anti-immobility effect of the extract (100 mg/kg, p.o.) was prevented by pretreatment of mice with p-chlorophenylalanine methyl ester (PCPA, 100 mg/kg, i.p., an inhibitor of serotonin synthesis, for four consecutive days), NAN-190 (0.5 mg/kg, i.p., a 5-HT(1A) receptor antagonist), WAY100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist), ketanserin (5 mg/kg, i.p., a 5-HT(2A/2C) receptor antagonist), MDL72222 (0.1 mg/kg, i.p., a 5-HT(3) receptor antagonist), prazosin (1 mg/kg, i.p., an alpha(1)-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an alpha(2)-adrenoceptor antagonist), SCH23390 (0.05 mg/kg, s.c., a D(1) receptor antagonist) or sulpiride (50 mg/kg, i.p., a D(2) receptor antagonist). It may be concluded that the hexanic extract of S. molle produces an antidepressant-like effect that seems to be dependent on its interaction with the serotonergic, noradrenergic and dopaminergic systems. These results provide evidence that the extract from S. molle shares with established antidepressants some pharmacological effects, at least at a preclinical level.

The relationship between CSF HVA/5-HIAA ratio and suicide intent in suicide attempters

There is a need to find stable biomarkers for suicidal behavior and suicide prediction. Reduced homovanillic acid/5-hydroxyindolacetic acid (HVA/5-HIAA) ratios in cerebrospinal fluid (CSF) in depressed suicide attempters have been reported. Suicide intent is a predictor of repetition of attempts and suicide. In the present study we investigated the relationship of HVA/5-HIAA ratio to the scales rating suicide intent and depressive symptoms. Fifteen consecutive medication-free male suicide attempters admitted to a psychiatric ward at the Karolinska Hospital and eight healthy male volunteers underwent lumbar puncture and had the CSF monoamine metabolite levels assayed. Patients were assessed with the Beck Suicide Intent Scale (SIS), the Montgomery Asberg Depression rating Scale (MADRS) and the Chapman Scale of Anhedonia. Within the suicide attempter group, HVA/5-HIAA ratio was significantly associated with the Suicide Intent Scale (SIS), but not with the MADRS scale or the Chapman Scale of Anhedonia indicating that the HVA/5-HIAA ratio may be a biomarker of suicide intent.