Familial suicide behaviour: association with probands suicide attempt characteristics and 5-HTTLPR polymorphism

Brain-derived and circulating vesicle profiles indicate neurovascular unit dysfunction in early Alzheimer's disease

Vascular factors that reduce blood flow to the brain are involved in apparition and progression of dementia. We hypothesized that cerebral hypoperfusion (CH) might alter the molecular compositions of brain intercellular communication mechanisms while affecting the neurovascular unit in preclinical and clinical human dementias. To test that hypothesis, mice were subjected to bilateral common carotid stenosis (BCAS) and the molecular compositions of brain-derived and circulating extracellular vesicles (EVs) were assessed. Murine brain vesicle profiles were then analyzed in parallel with brain EVs from post-mortem subjects affected by preclinical Alzheimer's Disease (AD) and mixed dementias. Brain EVs were identified with molecular mediators of hypoxia responses, neuroprotection and neurotoxicity in BCAS mice, patterns also partially resembled by subjects with preclinical AD and mixed dementias. Together these findings indicate that brain EVs represent a promising source of therapeutic targets and circulating markers of neurovascular insult in idiopathic dementias. Furthermore, the results obtained generate novel and compelling hypotheses about the molecular involvement of the vascular component in the etiology of human dementias.

Association between the SLC6A4 gene and schizophrenia: an updated meta-analysis

BACKGROUND

In order to explore the association between the SLC6A4 gene and the risk of schizophrenia, an updated meta-analysis was conducted using a total of 46 scientific articles.

METHODS

Through a literature search, papers studied included 35 articles on serotonin-transporter-linked polymorphic region (5-HTTLPR) with 8,752 cases and 10,610 controls, 17 articles on second intron variable number of tandem repeats with 7,284 cases and 8,544 controls, four studies on rs1042173 with 1,351 cases and 2,101 controls, and four studies on rs140700 with 1,770 cases and 2,386 controls. Pooled, subgroup, and sensitivity analyses were performed, and the results were visualized by forest and funnel plots.

RESULTS

An association between 5-HTTLPR and the risk of schizophrenia was not found, except for an Indian subgroup analysis (P_z =0.014, OR =1.749, 95% CI =1.120-2.731). A 10 repeats/12 repeats (10R/12R) genotype was a protective factor against schizophrenia (P_z =0.020, OR =0.789, 95% CI =0.646-0.963), but a 12R/12R genotype was a risk factor for schizophrenia (P_z =0.004, OR =1.936, 95% CI =1.238-3.029) in the pooled analyses. In Caucasians, a GG genotype of rs1042173 may be a risk factor for schizophrenia (P_z =0.006, OR =1.299, 95% CI =1.079-1.565). No association was found between rs140700 and the risk for schizophrenia.

CONCLUSION

Through meta-analysis, we were able to gain insight into previously reported associations between SLC6A4 polymorphism and schizophrenia.

Polymorphism in CRHR1 gene affects the IL-1β levels in suicidal attempters

Approximately one million people commit suicide every year, being suicide attempts and ideation even more common. Changes in stress response and activation of the immune system have been associated with suicide risk. Here we investigated the interaction between immune system and HPA axis alterations in the suicide risk, looking for the influence of rs110402 CRHR1 SNP in the IL-1β levels according to suicide ideation and attempt. This study evaluated 171 subjects of which 15 had suicidal ideation, 20 had suicide attempt and 136 were controls. Genotyping was performed by real-time PCR and IL-1β levels were measured by ELISA. Our data showed that for each point increase in IL-1β levels the risk of suicide attempt increased 5% [relative risk = 1.05 (95% CI: 1.0-1.10)]. After sample stratification by rs110402 SNP genotypes, we observed that in subjects carrying the A allele the risk raised to 15% [relative risk = 1.15 (95% CI: 1.03-1.28)], suggesting an apparent effect modification. Thus, this study showed that alterations in CRHR1 gene were associated with higher levels of IL-1β, and increased risk for suicide, reinforcing the importance of multifactorial interactions of biological markers for psychiatric disorders.

Suicide behavior as a quantitative trait and its genetic background

INTRODUCTION

Studies have not given yet a clear answer what is the genetic background of suicidal predisposition. The associations between polymorphisms of the TPH1 and 5-HTTLPR genes and violent suicidal behavior was revealed with the least inconsistencies.

METHOD

We selected 10 "strong candidate genes" and 35 SNPs, SLC6A4 and ACP1 for replication study. We searched associations between precisely described suicidal phenotype in 825 affective patients and polymorphisms of selected neurobiological pathways genes as well as their interactions that constitute suicidal risk.

RESULTS

The results confirm the role of TPH1, TPH2, 5HT2A, CRHR1 and ACP1 variants in the risk of suicidal behavior.

LIMITATIONS

In our study we analyzed limited number of candidate genes and only one of them is linked to lithium mechanism of action. We had no data on pharmacological treatment of investigated patients and its relation to the time of suicide attempt.

CONCLUSION

Our results indicate that polymorphisms of various signaling pathways are involved in the pathogenesis of suicidal behavior. Non-genetic factors are also involved in the risk of suicidal attempts.

Serotonin-Related Gene Polymorphisms and Asymptomatic Neurocognitive Impairment in HIV-Infected Alcohol Abusers

HIV-infected individuals continue to experience neurocognitive deterioration despite virologically successful treatments. While the cause remains unclear, evidence suggests that HIV-associated neurocognitive disorders (HAND) may be associated with neurobehavioral dysfunction. Genetic variants have been explored to identify risk markers to determine neuropathogenesis of neurocognitive deterioration. Memory deficits and executive dysfunction are highly prevalent among HIV-infected adults. These conditions can affect their quality of life and HIV risk-taking behaviors. Single nucleotide polymorphisms in the SLC6A4, TPH2, and GALM genes may affect the activity of serotonin and increase the risk of HAND. The present study explored the relationship between SLC6A4, TPH2, and GALM genes and neurocognitive impairment in HIV-infected alcohol abusers. A total of 267 individuals were genotyped for polymorphisms in SLC6A4 5-HTTLPR, TPH2 rs4570625, and GALM rs6741892. To assess neurocognitive functions, the Short Category and the Auditory Verbal Learning Tests were used. TPH2 SNP rs4570625 showed a significant association with executive function in African American males (odds ratio 4.8, 95% CI, 1.5–14.8; P = 0.005). Similarly, GALM SNP rs6741892 showed an increased risk with African American males (odds ratio 2.4, 95% CI, 1.2–4.9; P = 0.02). This study suggests that TPH2 rs4570625 and GALM rs6741892 polymorphisms may be risk factors for HAND.

Immune dysfunction in bipolar disorder and suicide risk: is there an association between peripheral corticotropin-releasing hormone and interleukin-1β?

OBJECTIVE

The aim of the present study was to investigate the relationship between peripheral levels of corticotropin-releasing hormone (CRH) and interleukin-1β (IL-1β) in individuals with bipolar disorder (BD) with and without suicide risk (SR), and controls.

METHODS

A total of 120 young adults (40 controls, 40 subjects with BD without SR, and 40 subjects with BD with SR) were enrolled from a population-based study carried out in the city of Pelotas, Brazil. BD and SR were assessed through the Mini International Neuropsychiatric Interview (MINI 5.0), and peripheral markers were evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Levels of CRH were significantly lower both in subjects with BD without SR (p = 0.04) and subjects with BD with SR (p = 0.02) when compared to controls. However, levels of IL-1β were increased in subjects with BD with SR (p = 0.05) when compared to controls. Sociodemographic and clinical variables, current mood episode, and use of psychiatric medications were not associated with changes in these markers. No correlation was found between peripheral levels of CRH and IL-1β (p = 0.60) in the population or in the BD with SR group (p = 0.88).

CONCLUSIONS

These results suggest that peripheral mechanisms linking stress hormones and the immune system might be critical patterns involved in suicidal behavior associated with BD.

Genetic variant of AKT1 and AKTIP associated with late-onset depression in a Brazilian population

OBJECTIVES

Examine the association between polymorphisms in the AKT1 and AKTIP genes and late-onset depression (LOD). Major depressive disorder is one of the most prevalent neuropsychiatric diseases. LOD is a disorder that starts after 65 years old. AKT1 is a downstream enzyme that has been implicated in the pathogenesis of neurotransmitter-related disorders, such as depression. The identification of a novel AKT1-binding protein (AKTIP) was pointed as an important new target. AKTIP binds directly to AKT1, enhancing the phosphorylation of regulatory sites, and this modulation are affected by AKT1 activation. The association of AKT1 and AKTIP polymorphisms with depressive symptoms was not investigated in LOD.

DESIGN

Genotype tagSNPs in the AKT1 and AKTIP in LOD patients and controls.

SETTINGS

An academic medical center.

PARTICIPANTS

Sample composed by 190 outpatients with LOD and 77 healthy individuals.

MEASURES

The participants were evaluated using Diagnostic and Statistical Manual IV criteria, MINI-PLUS and the Geriatric Depression Scale.

RESULTS

Our findings suggested an association between the tagSNP rs3730358 homozygous A/A (p = 0.006) and LOD. A strong association of allele A and increased association for LOD was demonstrated with tagSNP rs3730358 (p-value = 0.003).

LIMITATIONS

Limitation include composition of our control group, where the exclusion criteria generated a kind of super-healthy older group what might have produced a hidden stratification when compared with the LOD.

CONCLUSION

This study is the first one to establish the association of the AKT1/AKTIP genes and LOD, and further studies are necessary to clarify the functional role of these proteins.

Genetic variability at IMPA2, INPP1 and GSK3β increases the risk of suicidal behavior in bipolar patients

Bipolar patients (BP) are at high risk of suicide. Causal factors underlying suicidal behavior are still unclear. However, it has been shown that lithium has antisuicidal properties. Genes involved in its putative mechanism of action such as the phosphoinositol and the Wnt/β-catenine pathways could be considered candidates for suicidal behavior (SB). Our aim was to investigate the association of the IMPA1 and 2, INPP1, GSK3α and β genes with suicidal behavior in BP. 199 BP were recruited. Polymorphisms at the IMPA1 (rs915, rs1058401 and rs2268432) and IMPA2 (rs66938, rs1020294, rs1250171 and rs630110), INPP1 (rs3791809, rs4853694 and 909270), GSK3α (rs3745233) and GSK3β (rs334558, rs1732170 and rs11921360) genes were genotyped. All patients were grouped and compared according to the presence or not of history of SB (defined as the presence of at least one previous suicidal attempt). Single SNP analyses showed that suicide attempters had higher frequencies of AA genotype of the rs669838-IMPA2 and GG genotype of the rs4853694-INPP1gene compared to non-attempters. Results also revealed that T-allele carriers of the rs1732170-GSK3β gene and A-allele carriers of the rs11921360-GSK3β gene had a higher risk for attempting suicide. Haplotype analysis showed that attempters had lower frequencies of A:A haplotype (rs4853694:rs909270) at the INPP1 gene. Higher frequencies of the C:A haplotype and lower frequencies of the A:C haplotype at the GSK-3β gene (rs1732170:rs11921360) were also found to be associated to SB in BP. Therefore, our results suggest that genetic variability at IMPA2, INPP1 and GSK3β genes is associated with the emergence of SB in BP.

The role of the serotonergic system at the interface of aggression and suicide

Alterations in serotonin (5-HT) neurochemistry have been implicated in the aetiology of all major neuropsychiatric disorders, ranging from schizophrenia to mood and anxiety-spectrum disorders. This review will focus on the multifaceted implications of 5-HT-ergic dysfunctions in the pathophysiology of aggressive and suicidal behaviours. After a brief overview of the anatomical distribution of the 5-HT-ergic system in the key brain areas that govern aggression and suicidal behaviours, the implication of 5-HT markers (5-HT receptors, transporter as well as synthetic and metabolic enzymes) in these conditions is discussed. In this regard, particular emphasis is placed on the integration of pharmacological and genetic evidence from animal studies with the findings of human experimental and genetic association studies. Traditional views postulated an inverse relationship between 5-HT and aggression and suicidal behaviours; however, ample evidence has shown that this perspective may be overly simplistic, and that such pathological manifestations may reflect alterations in 5-HT homoeostasis due to the interaction of genetic, environmental and gender-related factors, particularly during early critical developmental stages. The development of animal models that may capture the complexity of such interactions promises to afford a powerful tool to elucidate the pathophysiology of impulsive aggression and suicidability, and identify new effective therapies for these conditions.

Impulsivity and the 5-HTTLPR polymorphism in a non-clinical sample

Background

Impulsivity has been associated with serotonergic system functions. However, few researchers have investigated the relationship between a polymorphism in the promoter of the serotonin transporter gene (5-HTTLPR) and the different components of impulsivity in a non-clinical population. The aim of this study was to investigate the relationship between a polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) and the different components of impulsivity in a non-clinical population.

Methodology/Principal Findings

We administered two neuropsychological tests, the Continuous Performance Task and the Iowa Gambling Task, to 127 healthy participants to measure their levels of motor, attentional and non-planning impulsivity. Then, these participants were grouped by genotype and gender, and their scores on impulsivity measures were compared. There were no significant differences between group scores on attentional, motor and non-planning impulsivity.

Conclusions/Significance

Our results suggest that 5-HTTLPR genotype is not significantly associated with subsets of impulsive behavior in a non-clinical sample when measured by neuropsychological tests. These findings are discussed in terms of the sensitivity of neuropsychological tests to detect impulsivity in a non-clinical population and the role of gender and race in the relationship between the 5-HTTLPR and impulsivity.

Is the serotonin transporter polymorphism (5-HTTLPR) a potential marker for suicidal behavior in bipolar disorder patients?

BACKGROUND

Suicide prediction is a huge challenge for mental health workers. Structured interviews based on epidemiological and clinical factors don't show effectiveness for suicide prevention. Biological markers, such as 5-HTTLPR, could help for identification of potential suicide attempters.

METHODS

We evaluated 198 bipolar patients and 103 health controls, using a structured interview according to DSM-IV criteria. Genotyping, blind of clinical assessment for identification of S carriers and structured interviews were performed in order to describe clinical and epidemiological factors which could be associated with suicide behavior. Statistical analyses were calculated by the x(2) test and logistic regression model.

RESULTS

We found that 26.77% and 16.67% had a lifetime history of non violent suicide attempt and violent suicide attempt, respectively. The clinical factors associated with violent and non violent suicide attempt had several differences. Violent suicide attempters had an earlier illness onset and had a higher number of psychiatric comorbidities (borderline personality disorder, panic disorder and alcoholism). The frequency of S allele carriers was higher only in those patients who had made a violent suicide attempt in their lifetime (x(2)=16.969; p=0.0001). In a logistic regression model including these factors, S allele carrier (5-HTTLPR) was the only factor associated with violent suicide attempt.

LIMITATIONS

Sample size and retrospective assessment of suicide behavior history are the limitations of this study.

CONCLUSIONS

Our study showed that serotonin polymorphism (5-HTTLPR) is strongly associated with violent suicidal behavior in BD patients. If confirmed, our results could be an important step to create a genetic tool for long-term suicide prediction.

Atypical depression is associated with suicide attempt in bipolar disorder

OBJECTIVE

There is a dearth of research focusing on factors associated with suicide attempts. High rates of atypical depression have been reported in studies including unipolar and bipolar II patients. In this study, the association between suicide attempt and atypical depression, in addition to other major risk factors, was evaluated in 390 bipolar I and II out-patients.

METHOD

Variables were defined according to DSM-IV criteria, and assessed with a Structured Interview for DSM-IV (axis I and II). History of suicide attempt was obtained through interviews with patients and relatives. Attempters and non-attempters were compared using univariate and multivariate analysis.

RESULTS

Attempters showed significantly higher rates of atypical depression, family history of completed suicide, depression at index episode and cluster B personality disorder.

CONCLUSION

Our results highlight the relevance of atypical depression in bipolar disorder. A more accurate identification of potential attempters may contribute to the development of effective preventive treatment strategies.

A review of psychiatric genetics research in the Brazilian population

OBJECTIVE AND METHOD: A large increase in the number of Brazilian studies on psychiatric genetics has been observed in the 1970's since the first publications conducted by a group of researchers in Brazil. Here we reviewed the literature and evaluated the advantages and difficulties of psychiatric genetic studies in the Brazilian population. CONCLUSION: The Brazilian population is one of the most heterogeneous populations in the world, formed mainly by the admixture between European, African and Native American populations. Although the admixture process is not a particularity of the Brazilian population, much of the history and social development in Brazil underlies the ethnic melting pot we observe nowadays. Such ethnical heterogeneity of the Brazilian population obviously brings some problems when performing genetic studies. However, the Brazilian population offers a number of particular characteristics that are of major interest when genetic studies are carried out, such as the presence of isolated populations. Thus, differences in the genetic profile and in the exposure to environmental risks may result in different interactions and pathways to psychopathology.

The role of 5-HTTLPR polymorphism in antidepressant-associated mania in bipolar disorder

BACKGROUND

The occurrence of mania during antidepressant treatment is a key issue in the clinical management of bipolar disorder (BD). The serotonin transporter gene is a candidate to be associated with antidepressant-associated mania (AAM) in some patients. This gene has a polymorphism within the promoter region (5-HTTLPR) with two allelic forms, the long (L) and the short (S) variants.

METHODS

We performed a case-control study to compare 5-HTTLPR genotype and allelic frequencies between 43 patients with a DSM-IV diagnosis of BD, with at least one manic/hypomanic episode associated with treatment with proserotonergic antidepressants (AAM+) and 69 unrelated, matched bipolar patients, who had been exposed to proserotonergic antidepressants without development of manic symptoms (AAM-(*)). Furthermore, we performed this comparison between a subgroup of 23 AAM+ patients that, when they presented AAM, were not using mood stabilizer (AAM+(*)) and 25 AAM- patients who used antidepressant without the concomitant use of a mood stabilizer (AAM-(*)). 5-HTTLPR genotyping was performed using PCR.

RESULTS

No significant differences were found between AAM+ and AAM-. Within the subgroups, our results show that S-carriers (LS+SS Genotypes) are more prone to make a manic/hypomanic episode associated with antidepressant (P=0.017).

LIMITATIONS

Our study is retrospective.

CONCLUSIONS

The 5-HTTLPR polymorphism may be considered a predictor of abnormal response to antidepressant in patients with BP, but this action is influenced by the presence of a mood stabilizer. Such observations reinforce that a correct diagnosis of bipolarity before the beginning of the treatment is essential, mainly for S-carriers patients.

Association of unipolar depression with gene polymorphisms in the serotonergic pathways in Han Chinese

OBJECTIVE

The present study aims to investigate the association of unipolar depression (UPD) with six serotonergic gene polymorphisms in Han Chinese.

METHODS

One hundred and thirty-two UPD patients and 180 healthy controls were genotyped for polymorphisms of six serotonergic genes, including tryptophan hydroxylase (TPH1 A218C), serotonin transporter promoter region (5-HTTLPR), serotonin receptor 2A (5-HT2AR -1438G/A), serotonin receptor 2C (5-HT2CR Cys23Ser), serotonin receptor 6 (5-HT6R C267T) and serotonin receptor 1Dβ (5-HT1DβR T371G). Symptomatic clusters were evaluated by the 24-item Hamilton Rating Scale for Depression (HAMD).

RESULTS

The frequencies of S/S genotype and S allele in 5-HTTLPR polymorphism were significantly higher in UPD patients than in healthy controls. There was a significant difference in distributions of genotypes in 5-HT2CR Cys23Ser polymorphism between UPD patients and control subjects, but the difference became no significant when the data were further stratified by gender. The patients with genotypes G/G and T/G of 5-HT1DβR T371G polymorphism had significantly lower scores of diurnal variation evaluated by HAMD than those with genotype T/T, while the patients with genotype T/G had significantly higher scores of hopelessness than those with genotypes G/G and T/T. There were no significant differences in genotypic and allelic distributions of TPH1 A218C, 5-HT2AR -1438G/A or 5-HT6R C267T polymorphisms between the case and control groups.

CONCLUSION

The study demonstrates that 5-HTTLPR and 5-HT2CR Cys23Ser polymorphisms might contribute to susceptibility of UPD, and the genotype T/T in 5-HT1DβR T371G polymorphism might be a risk factor for diurnal variation, while T/G might be a protective factor against hopelessness in Han Chinese populations.

The genetics of suicide: a critical review of molecular studies

Genetic epidemiology research has shown that genes contribute to suicide risk. Unfortunately, the first 30 years of candidate-based association studies have provided little information about the specific genetic contributors. This article reviews genetic association studies of suicidal phenotypes published to date. Possible theoretical, methodological, and operational challenges accounting for the modest success of association studies in the field are also discussed. The authors conclude that future research may benefit from using a more systematic and comprehensive selection of candidate genes and variants, examining gene-environment and gene-gene interactions, and investigating higher-order moderators.

Is the 5-HTTLPR polymorphism associated with bipolar disorder or with suicidal behavior of bipolar disorder patients?

The serotonin transporter gene has a 44 bp insertion/deletion polymorphism within the promoter region (5-HTTLPR) with two allelic forms, the long (L) and the short (S) variants. Association between the low-activity S variant and bipolar disorder (BPD) has been shown but its replication has not been consistent. It has also been described as an association between the S allele and suicidal behavior. Since suicidal behavior is a rather frequent event in BPD, an important question is whether suicidality, instead of bipolarity itself, could be related to S allele. We assessed 351 subjects (167 bipolar inpatients and 184 healthy controls). Diagnosis was conducted by a psychiatrist using a structured interview (MINI-PLUS), according to DSM-IV criteria. Suicidal behavior was assessed using a semi-structured instrument and a review of medical records. Genotyping of the 5-HTTLPR was performed using PCR. There were 77 patients with a history of previous suicide attempts. Bipolar patients and healthy controls showed comparable genotypic and allelic frequencies. Patients carrying the S allele made violent suicide attempts more frequently (chi(2) = 20.2; P = 0.0001) and made more suicide attempts (t = 2.6; P = 0.01). We were able to show an association between the S allele and suicidal behavior but not with BPD. Our data suggest that a phenotypic stratification, taking into account the suicidal behavior history, is of pivotal importance when performing association studies between BPD and 5-HTTLPR genotypes, which could explain previous contradictory results.

Social Modeling in the Transmission of Suicidality

Abstract. Evidence from twin, adoption, and family studies suggests that there is strong aggregation of suicidal behaviors in some families. By comparison, the role of social modeling through peers has yet to be convincingly established. This paper uses data from four large studies (the WHO/EURO Multicentre Study on Suicidal Behaviour, the WHO/SUPRE-MISS, the CASE study, and the Queensland Suicide Register) to compare the effects of exposure to fatal and nonfatal suicidal behavior in family members and nonfamilial associates on the subsequent suicidal behavior of male and female respondents of different ages. Across all studies, we found that prior suicidal behaviors among respondents' social groups were more important predictors of suicidal behavior in the respondents themselves than previous research had indicated. Community-based suicide attempters in the WHO SUPRE-MISS had higher rates of exposure to prior suicide in nonfamilial associates than in family members. In an adolescent population, exposure to prior fatal suicidal behavior did not predict deliberate self-harm when exposure to nonfatal suicidal behavior (both familial and social) were controlled for, but exposure to nonfatal suicidal behaviors in family and friends was predictive of deliberate self-harm and suicide ideation, even after controlling for exposure to fatal suicidal behavior. The potential impact of “containment” of information regarding suicidal behaviors as a prevention initiative is discussed, in light of information behavior principles of social marketing.

Variables associated with familial suicide attempts in a sample of suicide attempters

Attempted suicide appears to be a familial behavior. This study aims to determine the variables associated with family history of attempted suicide in a large sample of suicide attempters. The sample included 539 suicide attempters 18 years or older recruited in an emergency room. The two dichotomous dependent variables were family history of suicide attempt (10%, 51/539) and of completed suicide (4%, 23/539). Independent variables were 101 clinical variables studied with two data mining techniques: Random Forest and Forward Selection. A model for family history of completed suicide could not be developed. A classificatory model for family history of attempted suicide included the use of alcohol in the intent and family history of completed suicide (sensitivity, specificity, 98.7%; and accuracy, 96.6%). This is the first study that uses a powerful new statistical methodology, data mining, in the field of familial suicidal behaviors and suggests that it may be important to study familial variables associated with alcohol use to better understand the familiality of suicide attempts.

Genetics of suicide

The concept that genetic factors contribute to the complex trait of suicidal behaviour has stimulated much work aimed at identifying susceptibility genes. So far molecular genetic studies focused on the serotonergic pathway as the intent to die and the lethality of suicide acts were related to the serotonergic system. Two genes have so far emerged as being involved in the vulnerability for suicidality: first, the intronic polymorphisms (A218C or A779C) of the tryptophan hydroxylase 1 (TPH1) gene, which was suggested as a quantitative risk factor for suicidal behaviour; second, the insertion/deletion polymorphism of the serotonin transporter gene (5-HTTLPR), which does not seem to be involved in general suicidal behaviour, but in violent and repeated suicide attempts. The data have further shown that the MAOA gene, which is consistently associated with impulsive-aggressive personality traits, is not related to suicide but might induce violent methods in subjects with other suicide risk factors. Predominantly negative were the findings with any type of the serotonin receptors and inconsistent with catecholamine-synthesizing and -metabolizing enzymes or with the dopaminergic receptors. This paper reviews the status of current knowledge in this area, points to the weakness of the investigations and presents new approaches beyond the serotonergic system.

Clinical features of depressed patients with or without a family history of alcoholism

OBJECTIVE

To compare clinical features of depressed subjects without alcoholism but with a family history of alcoholism to a depressed group without alcoholism and without a family history of alcoholism.

METHOD

Clinical and demographic data of 209 depressed subjects without a history of alcoholism in first-degree relatives and 73 depressed individuals with a history of alcoholism in first-degree relatives were compared. Subjects with a personal history of alcoholism were excluded.

RESULTS

Depressed subjects with a family history of alcoholism have a significantly higher prevalence of reported childhood physical and sexual abuse and post-traumatic stress disorder (PTSD), make more suicide attempts, and have greater intent to die at the time of their most lethal suicide attempt, compared to depressed subjects without a family history of alcoholism.

CONCLUSION

Depressed patients with a family history of alcoholism are at greater risk for suicidal behavior and PTSD and may require more careful management.