The possible contributory role of the S allele of 5-HTTLPR in the emergence of suicidality

From parents to children: associations of traffic risks with impulsivity, family relationships and serotonin transporter genotype

Road traffic injuries are the leading cause of death for young adults, and parents play a major role in shaping their traffic behaviour. Higher impulsivity (predictor of higher traffic risk) has been shown to be dependent on family relations and the serotonin transporter gene promoter polymorphism (5-HTTLPR). The specific mechanisms for the inheritance of risky traffic behaviour from parents to children are not clear, and the genetic aspect has not been studied before. We used data of Estonian Children Personality Behaviour and Health Study subjects (n = 596, mean age = 25.2 ± 0.6) and their parents (mothers, n = 460, mean age = 52.1 ± 5.8; fathers, n = 339, mean age = 54.1 ± 6.5). Family relationships scale, traffic risk questionnaires and Adaptive and Maladaptive Impulsivity Scale were filled out. The increased risk-taking behaviour of parents and worse quality of family relationship were significant predictors of higher traffic risk among subjects. Family support and impulsivity of fathers significantly predicted the subjects' traffic risk score in interaction with 5-HTTLPR genotype: l'/l' homozygous subjects with adaptively impulsive fathers had higher traffic risk, whereas for s'-allele carrying subjects family support was more significant. Parental role modelling and family relationships are significant predictors of future traffic behaviour of the child. Whether the behavioural example of the father or the influence of family relationships is more important in predicting future risky traffic behaviour, depends on the 5-HTTLPR genotype of the child.

The Role of Pharmacogenetics in Personalizing the Antidepressant and Anxiolytic Therapy

Pharmacotherapy for neuropsychiatric disorders, such as anxiety and depression, has been characterized by significant inter-individual variability in drug response and the development of side effects. Pharmacogenetics, as a key part of personalized medicine, aims to optimize therapy according to a patient's individual genetic signature by targeting genetic variations involved in pharmacokinetic or pharmacodynamic processes. Pharmacokinetic variability refers to variations in a drug's absorption, distribution, metabolism, and elimination, whereas pharmacodynamic variability results from variable interactions of an active drug with its target molecules. Pharmacogenetic research on depression and anxiety has focused on genetic polymorphisms affecting metabolizing cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT) enzymes, P-glycoprotein ATP-binding cassette (ABC) transporters, and monoamine and γ-aminobutyric acid (GABA) metabolic enzymes, transporters, and receptors. Recent pharmacogenetic studies have revealed that more efficient and safer treatments with antidepressants and anxiolytics could be achieved through genotype-guided decisions. However, because pharmacogenetics cannot explain all observed heritable variations in drug response, an emerging field of pharmacoepigenetics investigates how epigenetic mechanisms, which modify gene expression without altering the genetic code, might influence individual responses to drugs. By understanding the epi(genetic) variability of a patient's response to pharmacotherapy, clinicians could select more effective drugs while minimizing the likelihood of adverse reactions and therefore improve the quality of treatment.

The Impact of Affective Temperaments on Suicidal Ideation and Behaviors: Results from an Observational Multicentric Study on Patients with Mood Disorders

Suicide ideation and behaviors are major health issues in the field of mental health. Several psychological and psychosocial factors have been taken into account as possible predictors of suicidality. Only recently affective temperaments have been considered as possible factors linked to suicide. This study aims to investigate the relationship between affective temperaments and suicidality, including the lifetime onset of suicide ideation, lifetime presence of suicide attempts and the total number of lifetime suicide attempts. This is a naturalistic multicentric observational study, involving outpatient units of seven University sites in Italy. Patients were administered with the short version of TEMPS-M and the Columbia Suicide Severity Rating Scale. A total of 653 participants were recruited, with a diagnosis of bipolar (55.7%), unipolar (35.8%) and cyclothymic disorder (8.4%). Regression models showed that the presence of lifetime suicide behaviors was increased in patients presenting trait related impulsivity (p < 0.0001), poor free-interval functioning (p < 0.05), higher number of affective episodes (p < 0.01), higher number of hospitalizations (p < 0.0001), cyclothymic and irritable affective temperaments (p < 0.05 and p < 0.05, respectively). Conversely, the presence of hyperthymic affective disposition reduced the likelihood of having suicidal behaviors (p < 0.01). Lifetime suicidal ideation was associated with trait-related impulsivity (p < 0.001), poor free-interval functioning (p < 0.05), higher number of affective episodes (p < 0.001) and of hospitalizations (p < 0.001). Depressive temperaments increased the likelihood of presenting suicidal ideation (p < 0.05), along with irritable temperaments (p < 0.01), contrary to hyperthymic affective (p < 0.05). Results of the present study confirm that affective disposition has a significant impact on the onset of suicidal ideation and behaviors, and that affective dispositions should be assessed in clinical settings to identify people at risk of suicide. Moreover, a wider clinical evaluation, including different clinical psychopathological dimensions, should be taken into consideration to develop effective preventive interventions.

Sex differences in maturation and aging of human personality on the basis of a recently developed complex hierarchical model of temperament and character

OBJECTIVE

The current study aimed to determine the changes in psychological function that come with age. The basis to assess psychological function was a hierarchical model of temperament, personality and character, previously developed by the authors.

METHODS

734 general population subjects completed the TEMPS-A, the TCI and the NEO-PI-3. Data were analysed with ANCOVA models.

RESULTS

The top superfactors showed no age change, however, age-related changes were identified in the higher and lower modules. There was a pattern of differences between the two genders in all levels of the model.

CONCLUSIONS

While there is stability with the two top factors of personality, there are age-related changes in lower-level modules probably indicating maturation, adaptation or changes in orientation through the adult life span. Gender differences in all levels including the two top superfactors, higher and lower modules reflect and explain differences in multiple aspects of internal experience, interaction and behaviour in the two genders. The results are clinically essential for incorporating age and gender-related differences of experience and behaviour in understanding temperamental implications in affective disorders also impacting their clinical course and management.Key PointsBased on the complex hierarchical temperament model four stages of maturation of human psychological function can be postulated.There is a very specific trait core of human mental function, which differs between genders and seems to be responsible for the longitudinal stability of the person's internal experience with the passing of the years.The findings are clinically essential for incorporating age and gender-related differences of experience and behaviour in understanding temperamental implications in affective disorders also impacting their clinical course and management.

Understanding the Complex of Suicide in Depression: from Research to Clinics

OBJECTIVE

Amongst psychiatric disorders, major depressive disorder (MDD) is the most prevalent, by affecting approximately 15-17% of the population and showing a high suicide risk rate equivalent to around 15%. The present comprehensive overview aims at evaluating main research studies in the field of MDD at suicide risk, by proposing as well as a schematic suicide risk stratification and useful flow-chart for planning suicide preventive and therapeutic interventions for clinicians.

METHODS

A broad and comprehensive overview has been here conducted by using PubMed/Medline, combining the search strategy of free text terms and exploded MESH headings for the topics of 'Major Depressive Disorder' and 'Suicide' as following: ((suicide [Title/Abstract]) AND (major depressive disorder [Title/Abstract])). All articles published in English through May 31, 2019 were summarized in a comprehensive way.

RESULTS

Despite possible pathophysiological factors which may explain the complexity of suicide in MDD, scientific evidence supposed the synergic role of genetics, exogenous and endogenous stressors (i.e., interpersonal, professional, financial, as well as psychiatric disorders), epigenetic, the hypothalamic-pituitary-adrenal stress-response system, the involvement of the monoaminergic neurotransmitter systems, particularly the serotonergic ones, the lipid profile, neuro-immunological biomarkers, the Brain-derived neurotrophic factor and other neuromodulators.

CONCLUSION

The present overview reported that suicide is a highly complex and multifaceted phenomenon in which a large plethora of mechanisms could be variable implicated, particularly amongst MDD subjects. Beyond these consideration, modern psychiatry needs a better interpretation of suicide risk with a more careful assessment of suicide risk stratification and planning of clinical and treatment interventions.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Affective Temperaments and Clinical Course of Bipolar Disorder: An Exploratory Study of Differences among Patients with and without a History of Violent Suicide Attempts

Background and Objectives: Suicide is the leading cause of death in patients with Bipolar Disorder (BD). In particular, the high mortality rate is due to violent suicide attempts. Several risk factors associated with suicide attempts in patients with BD have been identified. Affective temperaments are associated with suicidal risk, but their predictive role is still understudied. The aim of this study is to assess the relationship between affective temperaments and personal history of violent suicide attempts. Materials and Methods: 74 patients with Bipolar Disorder type I (BD-I) or II (BD-II) were included. All patients filled in the short version of Munster Temperament Evaluation of the Memphis, Pisa, Paris and San Diego (short TEMPS-M) and the Temperament and Character Inventory, revised version (TCI-R). The sample was divided into two groups on the basis of a positive history for suicidal attempts and the suicidal group was further divided into two subgroups according to violent suicide attempts. Results: Violent suicide attempts were positively associated with the cyclothymic temperament and inversely to the hyperthymic one. BD-I patients and patients with a clinical history of rapid cycling were significantly more represented in the group of patients with a history of violent suicide attempts. Conclusions: Our study highlights that several clinical and temperamental characteristics are associated with violent suicide attempts, suggesting the importance of affective temperaments in the clinical management of patients with BPI.

The personal experience of severe suicidal behaviour leads to negative attitudes towards self- and other's suicidal thoughts and behaviours: A study of temperaments, coping strategies, and attitudes towards suicide among medical students

The attitudes individuals have towards suicidal behaviour, be it their own or others', and their capacity for developing specific coping strategies are influenced by affective temperaments that play a significant role in emotional regulation. However, few studies have investigated these specific patterns with a view to stratify them according to the severity of suicidal behaviours in medical students. The Pearson χ2 test for the comparison of categorical variables, the t-test for independent samples of continuous variables and logistic regression analysis were used to compare the association among temperaments, coping strategies, and attitudes towards suicide in a sample of medical students who attend the School of Medicine, Genoa. Severe suicidal thoughts and behaviours relative to those who were not at risk for suicide were also revealed. The severe suicidal thought and behaviour group had significantly more anxious and cyclothymic temperaments together with a higher use of dis-adaptive, lower emotional focus coping strategies, and higher self-reproaching, criticizing, and judgemental attitudes towards suicidality compared to the no severe suicidal thought and behaviour group. The identified pattern suggests the need for clinicians to carefully consider the complex interplay of clinical features which characterize severely at risk for suicide young adults in order to develop effective and comprehensive prevention strategies.

The influence of the serotonin transporter gene 5-HTTLPR polymorphism on suicidal behaviors: a meta-analysis

Suicidal Behavior (SB) is the second leading cause of death among youths worldwide and the tenth among all age groups. Inherited genetic differences have a role in suicidality with heritability ranging from 30 to 55%. The SLC6A4 5-HTTLPR gene variant has been largely investigated for association with SB, with controversial results. In this work, we sought to determine whether the results of previous meta-analyses were confirmed or modified subsequent to the inclusion of more recent literature data. An electronic literature search was performed to identify relevant studies published until July 2018. Data were analysed through RevMan v5.3. Subgroup and sensitivity meta-analyses were performed considering different SB sub-phenotypes, ethnicity, gender and psychiatric diagnostic categories. Our literature search yielded 1186 articles; among these, we identified 45 pertinent case-control studies (15,341 subjects). No association was found between low-expressing alleles or genotypes (S + L_G alleles or S' carrier genotypes) and SB in the primary analyses. However, low-expressing alleles (S + L_G) were associated with an increased risk of Violent Suicide Attempt (OR = 1.44, C.I. 1.17-1.78, p = .0007). An effect of the same alleles on SB was found in a subpopulation of substance abusers, but this result was not confirmed after the exclusion of healthy subjects from the control group. The other sensitivity meta-analyses did not show any significant effect. Our findings contribute to clarify the conflicting previous evidence by suggesting an association between the 5-HTTLPR and Violent SB. Nonetheless, many other modulators, including environmental factors and epigenetic mechanisms may act to further increase the level of complexity.

Modeling human temperament and character on the basis of combined theoretical approaches

BACKGROUND

Although there are several models on the structure of human temperament, character and personality, the majority follow a single approach, providing a unilateral and overly theoretical construct which is unsuitable for clinical application. The current study aimed to develop a complex and comprehensive model of temperament and character by empirically combining relevant existing theories.

METHODS

The study included 734 healthy general population subjects aged 40.80 ± 11.48 years, who completed the TEMPS-A, TCI and NEO-PI-3 questionnaires. Data were analyzed in a multistep approach using Exploratory Factor analysis and forward stepwise linear regression.

RESULTS

The results yielded two highest order factors (Self and Self-Environment Interaction), six middle order factors (Emotional Self, Cognitive Self, Social Emotionality, Emotional and Cognitive Control, Ethical Emotionality and Behavior, Social Emotionality and Behavior) and 12 factors at the bottom (Ego Resiliency, Ego Strength, Intrapersonal Emotion, Personal Space Cognition, Interpersonal Cognition, Emotional Creativity, Externalized Interpersonal Emotion, Internalized Interpersonal Emotion, Emotional Motivation, Self-Discipline, Ethical Values and Ethical Behavior).

CONCLUSIONS

The current study developed a complex hierarchical model of temperament and character on the basis of empirical data from several temperament theories. An important feature of the new temperamental model is the frequent admixture of emotional and cognitive processes within the same module. This model expands the field to include elements probably corresponding to meta-cognition mechanisms and complex interactions between affective and cognitive control, which may provide useful in understanding and treating affective disorders as well.

Temperament traits in suicidal and non-suicidal mood disorder patients in Taiwan

Suicide is a major social and clinical problem in Asia. Although studies have suggested that personality traits are possible risk factors for suicide, no study has been conducted among Chinese to compare the temperament traits of suicidal and non-suicidal mood disorder patients with those of healthy controls. This study compared temperament traits of two patient groups, those with a mood disorder who have attempted suicide (n=204), and those with a mood disorder who have not attempted suicide (n=160), and compared the traits of these patients to those of healthy controls (n=178), assessed by Cloninger's Tridimensional Personality Questionnaire and the Brown-Goodwin Aggression Inventory. Patients with suicidal attempts had significantly higher novelty seeking and aggression scores than healthy controls and patients without suicidal attempts. Two groups of patients with mood disorder had significantly higher harm avoidance scores than the healthy controls. However, patients with suicidal attempts did not have higher harm avoidance scores than patients without suicidal attempts. This study confirms findings that harm avoidance and mood disorder are related, and extends them by suggesting that those with a mood disorder and suicide attempts have higher novelty seeking and lifetime aggression scores than those without suicidal attempt, either patients or healthy controls.

Affective temperaments, as measured by TEMPS-A, among self-poisoning nonlethal suicide attempters

Suicidal behaviors are serious public health problems. The prominent association of mood disorders with suicide, along with the renaissance of the spectrum concept of psychiatric disorders in the recent decades, prioritizes the investigation of temperament variants in suicidal individuals. This study aimed to explore the relationship between affective temperaments and nonviolent suicide attempts. We administered Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Auto questionnaire (TEMPS-A) to 141 (27 males and 114 females) consecutive self-poisoning non-lethal suicide attempters at a Medical Toxicology Center and a sex and age matched group of healthy individuals (28 males, 112 females). Female suicide attempters scored significantly higher in depressive, cyclothymic, irritable, and anxious temperaments compared with female controls, whereas male cases' scores were significantly higher in depressive and anxious subscales compared with control males. Except for hyperthymic temperament which did not reveal any significant effects, depressive (OR: 11.5), cyclothymic (OR: 3.8), irritable (OR: 2.3), and anxious (OR: 8.8) temperaments were predictors for nonviolent suicide attempts. Therefore, this study replicated the evidence for the strong association of depressive temperament with suicide attempts. The hyperthymic temperament appeared to have neither protective nor predisposing influence. Further studies are needed to identify the role of this independent temperament.

Financial difficulties but not other types of recent negative life events show strong interactions with 5-HTTLPR genotype in the development of depressive symptoms

Several studies indicate that 5-HTTLPR mediates the effect of childhood adversity in the development of depression, while results are contradictory for recent negative life events. For childhood adversity the interaction with genotype is strongest for sexual abuse, but not for other types of childhood maltreatment; however, possible interactions with specific recent life events have not been investigated separately. The aim of our study was to investigate the effect of four distinct types of recent life events in the development of depressive symptoms in a large community sample. Interaction between different types of recent life events measured by the List of Threatening Experiences and the 5-HTTLPR genotype on current depression measured by the depression subscale and additional items of the Brief Symptom Inventory was investigated in 2588 subjects in Manchester and Budapest. Only a nominal interaction was found between life events overall and 5-HTTLPR on depression, which failed to survive correction for multiple testing. However, subcategorising life events into four categories showed a robust interaction between financial difficulties and the 5-HTTLPR genotype, and a weaker interaction in the case of illness/injury. No interaction effect for the other two life event categories was present. We investigated a general non-representative sample in a cross-sectional approach. Depressive symptoms and life event evaluations were self-reported. The 5-HTTLPR polymorphism showed a differential interaction pattern with different types of recent life events, with the strongest interaction effects of financial difficulties on depressive symptoms. This specificity of interaction with only particular types of life events may help to explain previous contradictory findings.

Cyclothymia reloaded: A reappraisal of the most misconceived affective disorder

Data emerging from both academic centers and from public and private outpatient facilities indicate that from 20% to 50% of all subjects that seek help for mood, anxiety, impulsive and addictive disorders turn out, after careful screening, to be affected by cyclothymia. The proportion of patients who can be classified as cyclothymic rises significantly if the diagnostic rules proposed by the DSM-5 are reconsidered and a broader approach is adopted. Unlike the DSM-5 definition based on the recurrence of low-grade hypomanic and depressive symptoms, cyclothymia is best identified as an exaggeration of cyclothymic temperament (basic mood and emotional instability) with early onset and extreme mood reactivity linked with interpersonal and separation sensitivity, frequent mixed features during depressive states, the dark side of hypomanic symptoms, multiple comorbidities, and a high risk of impulsive and suicidal behavior. Epidemiological and clinical research have shown the high prevalence of cyclothymia and the validity of the concept that it should be seen as a distinct form of bipolarity, not simply as a softer form. Misdiagnosis and consequent mistreatment are associated with a high risk of transforming cyclothymia into severe complex borderline-like bipolarity, especially with chronic and repetitive exposure to antidepressants and sedatives. The early detection and treatment of cyclothymia can guarantee a significant change in the long-term prognosis, when appropriate mood-stabilizing pharmacotherapy and specific psychological approaches and psychoeducation are adopted. The authors present and discuss clinical research in the field and their own expertise in the understanding and medical management of cyclothymia and its complex comorbidities.

Schizophrenia as a disorder of molecular pathways

Over the last decade, transcriptome studies of postmortem tissue from subjects with schizophrenia revealed that synaptic, mitochondrial, immune system, gamma-aminobutyric acidergic, and oligodendrocytic changes are all integral parts of the disease process. The combined genetic and transcriptomic studies argue that the molecular underpinnings of the disease are even more varied than the symptomatic diversity of schizophrenia. Ultimately, to decipher the pathophysiology of human disorders in general, we will need to understand the function of hundreds of genes and regulatory elements in our genome and the consequences of their overexpression and reduced expression in a developmental context. Furthermore, integration of knowledge from various data sources remains a monumental challenge that has to be systematically addressed in the upcoming decades. In the end, our success in interpreting the molecular changes in schizophrenia will depend on our ability to understand the biology using innovative ideas and cannot depend on the hope of developing novel, more powerful technologies.

Temperamental and genetic predictors of suicide attempt and self-mutilation

BACKGROUND AND AIMS

Literature findings mainly support the notion that suicide attempts (SA) and self-mutilating behavior (SMB) are distinct behaviors, although they may share common psychopathological features. In the present paper we aimed to identify behavioral phenotypes in patients with SA, SMB, or both (SAM) and to analyze the association with candidate genes.

METHODS

One hundred forty-two inpatients with a history of SA (n = 86), SMB (n = 22), and SAM (n = 39) were included in this study. Subjects were evaluated using the Tridimensional Personality Questionnaire (TPQ) and the Buss-Durkee Hostility Inventory (BDHI). Polymorphisms within serotonin transporter (SLC6A4, HTTLPR), catechol-O-methyl transferase (COMT, Val158Met), and tryptophan hydroxylase (TPH, 218C>A) were also analyzed.

RESULTS

Principal component factor analysis including the BDHI and TPQ produced 3 factors that could classify the 3 groups of patients with good sensitivity. However, only the 'pure suicidal' factor had a sufficient positive predictive value. This factor was characterized by high levels of persistence (PS) and, to a lower extent, reward dependence. The distribution of genotypes was not different across patient groups for all polymorphisms, but the SS genotype of HTTLPR was significantly associated with the 'self-mutilation' factor, characterized by high levels of hostile traits, novelty seeking, and harm avoidance.

CONCLUSION

The results of the present study suggest that different and overlapping temperamental traits in suicidal and self-mutilating patients are present, although only high levels of PS could predict SA repetition. Finally, HTTLPR may mediate the risk for SMB through modulation of some temperamental traits.

Serotonergic genes and suicidal ideation 2 weeks and 1 year after stroke in Korea

OBJECTIVES

Serotonergic genes are associated with suicidal behavior; this association has not been tested in stroke survivors, however. In this study, we investigated whether serotonin transporter (5-HTT) and serotonin 2a receptor (5-HTR2a) genes were associated with suicidal ideation at 2 weeks and at 1 year after stroke.

METHODS

A total of 286 patients were evaluated 2 weeks after stroke, and 222 (78%) participated in a follow-up evaluation one year later. Suicidal ideation was ascertained using the "suicidal thoughts" item of the Montgomery and Asberg Depression Rating Scale. Associations between suicidal ideation and 5-HTTLPR, STin2 VNTR, 5-HTR2a 1438A/G, and 5-HTR2a 102T/C genotypes were estimated using logistic regression models, and gene-gene interactions were investigated using the generalized multifactor dimensionality reduction method after adjustment for potential covariates, including depression.

RESULTS

The 5-HTR2a 1438 A/A genotype was significantly associated with suicidal ideation 2 weeks after stroke, before and after statistical adjustment. The 5-HTTLPR short allele was associated with suicidal ideation 2 weeks after stroke, although the significance of this finding was not evident after adjustment. No significant associations were observed between any genotype and suicidal ideation one year after stroke. No significant gene-gene interactions were detected.

CONCLUSIONS

Individuals with the 5-HTR2a 1438 A/A genotype were more susceptible to suicidal ideation 2 weeks after stroke. Careful evaluation and management are indicated for those with increased genetic vulnerability, particularly during the acute phase of stroke.

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.

Behavioral genetics and criminal responsibility at the courtroom

Several questions arise from the recent use of behavioral genetic research data in the courtroom. Ethical issues concerning the influence of biological factors on human free will, must be considered when specific gene patterns are advocated to constrain court's judgment, especially regarding violent crimes. Aggression genetics studies are both difficult to interpret and inconsistent, hence, in the absence of a psychiatric diagnosis, genetic data are currently difficult to prioritize in the courtroom. The judge's probabilistic considerations in formulating a sentence must take into account causality, and the latter cannot be currently ensured by genetic data.

Serotonin and interleukin-6: the role of genetic polymorphisms in IFN-induced neuropsychiatric symptoms

BACKGROUND

Cytokines and serotonin neurotransmission may play an important role on the development of psychopathological symptoms during interferon (IFN) treatment. The aim of the present study was to investigate the association between IFN-induced depression, anxiety and fatigue and functional genetic variants at the interleukin-6 gene (IL-6) and serotonin transporter gene (SERT).

METHODS

385 consecutive Caucasian outpatients with chronic hepatitis C initiating treatment with IFN-alpha and ribavirin were included. All patients were interviewed at baseline using the Structured Clinical Interview for DSM-IV (SCID-I) and those with a current major depressive disorder or anxiety disorder before starting treatment were excluded. Depression and anxiety were assessed at baseline during the treatment (at 4, 12, 24 and 48 weeks) using the Hospital Anxiety and Depression Scale and fatigue was evaluated using a visual analogue scale. The 5-HTTLPR region of SERT gene and the functional polymorphism located at the promoter region of IL-6 gene (rs1800795) were genotyped.

RESULTS

Genotypic distribution was in the Hardy-Weinberg equilibrium for SERT (p=0.41) and for IL-6 (p=0.72) polymorphisms. At baseline we found only a significant effect of IL-6 polymorphism on fatigue symptoms. During antiviral treatment we reported that subjects with CC genotype (IL-6) presented significantly lower changes from baseline in IFN-induced depression (p=0.005) and IFN-induced anxiety (p=0.004). We did not find statistically significant differences on depression (p=0.21) or anxiety (p=0.15) between SS/SL and LL genotypes of SERT.

CONCLUSIONS

Genetic variations in the IL-6 gene increase the risk of IFN-induced depression and anxiety. The IL-6 polymorphism was associated with fatigue rates in patients with chronic hepatitis C before treatment. Our study confirms the role of inflammatory mechanisms in IFN-induced psychopathological symptoms.

Positron emission tomography quantification of serotonin transporter in suicide attempters with major depressive disorder

BACKGROUND

Several lines of evidence implicate abnormal serotonergic function in suicidal behavior and completed suicide, including low serotonin transporter binding in postmortem studies of completed suicide. We have also reported low in vivo serotonin transporter binding in major depressive disorder (MDD) during a major depressive episode using positron emission tomography (PET) with [(11)C]McN5652. We quantified regional brain serotonin transporter binding in vivo in depressed suicide attempters, depressed nonattempters, and healthy controls using PET and a superior radiotracer, [(11)C]DASB.

METHODS

Fifty-one subjects with DSM-IV current MDD, 15 of whom were past suicide attempters, and 32 healthy control subjects underwent PET scanning with [(11)C]DASB to quantify in vivo regional brain serotonin transporter binding. Metabolite-corrected arterial input functions and plasma free-fraction were acquired to improve quantification.

RESULTS

Depressed suicide attempters had lower serotonin transporter binding in midbrain compared with depressed nonattempters (p = .031) and control subjects (p = .0093). There was no difference in serotonin transporter binding comparing all depressed subjects with healthy control subjects considering six a priori regions of interest simultaneously (p = .41).

CONCLUSIONS

Low midbrain serotonin transporter binding appears to be related to the pathophysiology of suicidal behavior rather than of major depressive disorder. This is consistent with postmortem work showing low midbrain serotonin transporter binding capacity in depressed suicides and may partially explain discrepant in vivo findings quantifying serotonin transporter in depression. Future studies should investigate midbrain serotonin transporter binding as a predictor of suicidal behavior in MDD and determine the cause of low binding.

Affective temperament, history of suicide attempt and family history of suicide in general practice patients

BACKGROUND

Untreated major affective disorders are strongly associated with suicidal behaviour; however, clinical, psychological and psycho-social risk factors also play a contributory role. Personal history and family history of suicide are also important predictors of suicidal behaviours, and are also a powerful marker of current major depressive episode in general practice patients. Affective temperaments, which can be considered the subaffective manifestations of major mood disorders also show a specific pattern of association with suicidal behaviour. In the present study our aim was to investigate the association between affective temperaments, personal history of suicide attempts and family history of completed suicide in primary practice patients.

METHODS

Five hundred and nine patients from 6 primary care practices completed the TEMPS-A, and were assessed concerning self-reported history of personal or family suicide.

RESULTS

We found that among those answering questions concerning suicide, 9.1% reported a family history of suicide in first and second degree relatives and 4.8% had at least one prior suicide attempt. Among those giving a positive answer to both questions, those who had a positive family history had significantly more frequent suicide attempts (15.4% vs. 4.0%). Patients with prior suicide attempts had a significantly higher score on the cyclothymic and depressive, and those with positive family history of suicide had on cyclothymic and anxious subscales.

LIMITATIONS

In the present study, personal and family history of suicide was assessed retrospectively and in a self-report way. The cross-sectional nature of this study and the facts that no current psychiatric morbidity has been investigated and only the documented history of depressive and anxiety disorders have been detected limit the generalisability of this study.

DISCUSSION

We found a significant relationship between depressive and cyclothymic affective temperament and personal history of suicide attempts, and between cyclothymic and anxious temperament and family history of completed suicide in first and second degree relatives. This is in line with previous findings showing a strong relationship between these affective temperaments and major mood episodes and that these temperaments are overrepresented among suicide attempters. Our findings also suggest that the presence of cyclothymic (and to lesser extent depressive) affective temperament in a patient with family history of completed suicide indicates a very high risk of suicidal behaviour.

An association study of suicide and candidate genes in the serotonergic system

INTRODUCTION

Strong evidence demonstrates a genetic susceptibility to suicidal behaviour and a relationship between suicide and mental disorders. The aim of this study was to test for association between suicide and five selected genetic variants, which had shown association with suicide in other populations.

METHOD

We performed a nationwide case-control study on all suicide cases sent for autopsy in Denmark between the years 2000 and 2007. The study comprised 572 cases and 1049 controls and is one of the largest genetic studies in completed suicide to date. The analysed markers were located within the Serotonin Transporter (SLC6A4), Monoamine Oxidase-A (MAOA) and the Tryptophan Hydroxylase I and II (TPH1 and TPH2) genes.

RESULTS

None of the genetic markers within SLC6A4, MAOA, TPH1 and TPH2 were significantly associated with completed suicide or suicide method in the basic association tests. Exploratory interaction test showed that the minor allele of rs1800532 in TPH1 has a protective effect for males younger than 35 years and females older than 50 years, whereas for the oldest male subjects, it tended to be a risk factor. We also observed a significant interaction between age-group and the 5-HTTLPR genotype (with and without rs25531) in SLC6A4. The long allele or high expression allele tends to have a protective effect in the middle age-group.

LIMITATION

We only analysed a limited number of genetic variants.

CONCLUSION

None of the analysed variants are strong risk factors. To reveal a better understanding of the genes involved in suicide, we suggest future studies should include both genetic and non-genetic factors.

Star-crossed? The association of the 5-HTTLPR s allele with season of birth in a healthy female population, and possible consequences for temperament, depression and suicide

BACKGROUND

Birth season has well-known effects on neuropsychiatric disorders, and may also influence genotype distribution by possibly influencing chance of conception via parental idiosyncratic conception patterns or survival of foetuses or infants. The 5-HTTLPR is associated with phenomena including affective temperaments or suicide which are also associated with birth season. Our aim was to investigate the association of 5-HTTLPR genotype and birth season in a healthy female population.

METHODS

Birth date and 5-HTTLPR genotype was determined for 327 psychiatrically healthy women. The association between presence of s allele and time of birth was analysed using generalized linear models.

RESULTS

A significant association between s allele frequency and time of birth was detected. S allele carrier frequency was marginally significantly higher in July borns and significantly lower in autumn borns.

LIMITATIONS

We investigated an adult sample so genotype frequency data do not reflect birth frequencies. Our sample consisted exclusively of females.

CONCLUSIONS

There is no clear explanation for the observed association, although idiosyncratic parental conception patterns, the association of 5-HTTLPR with sudden infant/intrauterine death, or other s allele-mediated behaviours may play a role. Our results are strikingly parallel with earlier data reporting a higher risk of completed suicide in July borns, and higher scores of July borns and lower scores of autumn borns on certain affective temperament scales, both of which are also associated with the s allele of 5-HTTLPR. Thus our results may add to the growing body of evidence regarding the etiological background of affective disorders.

Altered functional protein networks in the prefrontal cortex and amygdala of victims of suicide

Probing molecular brain mechanisms related to increased suicide risk is an important issue in biological psychiatry research. Gene expression studies on post mortem brains indicate extensive changes prior to a successful suicide attempt; however, proteomic studies are scarce. Thus, we performed a DIGE proteomic analysis of post mortem tissue samples from the prefrontal cortex and amygdala of suicide victims to identify protein changes and biomarker candidates of suicide. Among our matched spots we found 46 and 16 significant differences in the prefrontal cortex and amygdala, respectively; by using the industry standard t test and 1.3 fold change as cut off for significance. Because of the risk of false discoveries (FDR) in these data, we also made FDR adjustment by calculating the q-values for all the t tests performed and by using 0.06 and 0.4 as alpha thresholds we reduced the number of significant spots to 27 and 9 respectively. From these we identified 59 proteins in the cortex and 11 proteins in the amygdala. These proteins are related to biological functions and structures such as metabolism, the redox system, the cytoskeleton, synaptic function, and proteolysis. Thirteen of these proteins (CBR1, DPYSL2, EFHD2, FKBP4, GFAP, GLUL, HSPA8, NEFL, NEFM, PGAM1, PRDX6, SELENBP1 and VIM,) have already been suggested to be biomarkers of psychiatric disorders at protein or genome level. We also pointed out 9 proteins that changed in both the amygdala and the cortex, and from these, GFAP, INA, NEFL, NEFM and TUBA1 are interacting cytoskeletal proteins that have a functional connection to glutamate, GABA, and serotonin receptors. Moreover, ACTB, CTSD and GFAP displayed opposite changes in the two examined brain structures that might be a suitable characteristic for brain imaging studies. The opposite changes of ACTB, CTSD and GFAP in the two brain structures were validated by western blot analysis.

Association between a genetic variant in the serotonin transporter gene (SLC6A4) and suicidal behavior in patients with schizophrenia

Background

The serotonin (5-hydroxytryptamin; 5-HT) system has a central role in the circuitry of cognition and emotions. Multiple lines of evidence suggest that genetic variation in the serotonin transporter gene (SLC6A4; 5-HTT) is associated with schizophrenia and suicidal behavior. In this study, we wanted to elucidate whether SLC6A4 variations is involved in attempted suicide among patients with schizophrenia in a Scandinavian case–control sample.

Methods

Patients diagnosed with schizophrenia from three Scandinavian samples were assessed for presence or absence of suicide attempts, based on record reviews and interview data. Seven SLC6A4 single nucleotide polymorphisms (SNPs) were genotyped in 837 schizophrenia patients and 1,473 control individuals. Association analyses and statistical evaluations were performed with the program UNPHASED (version 3.0.9).

Results

We observed an allele association between the SNP rs16965628, located in intron one of SLC6A4, and attempted suicide (adjusted p-value 0.01), among patients with schizophrenia. No association was found to a diagnosis of schizophrenia, when patients were compared to healthy control individuals.

Conclusion

The gene SLC6A4 appears to be involved in suicidal ideation among patients with schizophrenia. Independent replication is needed before more firm conclusions can be drawn.

Cyclothymic-depressive-anxious temperament pattern is related to suicide risk in 346 patients with major mood disorders

BACKGROUND

Suicidal behavior is one of the most alarming signs not only in psychiatry, and current major depressive episode is the most frequent medical condition among suicide victims and attempters. The aim of the study was to investigate the relationship between the individual pattern of affective temperaments, non-typical symptoms of depression as measured with the Gotland Scale for Male Depression (GSMD), hopelessness and suicidal behavior in major mood disorder patients.

METHODS

Participants were 346 adult inpatients (151 men and 195 women) with major mood disorders consecutively admitted to the Department of Psychiatry of the Sant'Andrea University Hospital in Rome, Italy. All the patients were administered the TEMPS-A, the GSMD, and the Beck Hopelessness Scale (BHS) and the Mini International Neuropsychiatric Interview (MINI).

RESULTS

A Two Step Cluster Analysis procedure, performed to reveal natural groupings within patients' response set, indicated that there were 2-groups: a cyclothymic-depressive-anxious group and a hyperthymic group. More than 81% of the patients with prevailing cyclothymic-depressive-anxious temperament had mild to severe suicidal risk on the MINI vs. only around 42% of the patients with prevailing hyperthymic temperament. Sixty-four percent of patients with prevailing cyclothymic-depressive-anxious temperament had BHS scores of 9 or higher versus only 13% of patients with prevailing hyperthymic temperament. Also, patients with prevailing cyclothymic-depressive-anxious temperament more likely had higher GSMD than patients with prevailing hyperthymic temperament.

LIMITATIONS

The correlational nature of the study limits causal conclusions to be drawn.

CONCLUSIONS

Our results indicate that affective temperament measure along with Gotland Scale for Male Depression could be useful tools in screening and identifying those affective disorder patients who are at higher risk of suicidal behavior.

Affective temperaments: from neurobiological roots to clinical application

The Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A) has grown to be a clinically important outcome measure in the diagnosis and the clinical course of mood disorders. However, temperaments, which represent the biologically stable core of personality, are not just antecedents of major affective disorders, but also serve as a reservoir of genetically advantageous traits for the survival of different cultures. The rapidly growing body of research in psychiatric and non-psychiatric fields even raises the question of temperament as a common root in psychiatric and somatic disorders, providing a new meaning for the construct of psychosomatic disorders. In this review we aim to summarize current knowledge on both the neurobiological background and clinical importance of affective temperaments including implications for future research. Orv. Hetil., 2011, 152, 1879–1886.

Interaction of 5-HTTLPR genotype and unipolar major depression in the emergence of aggressive/hostile traits

OBJECTIVE

The 5-HTTLPR polymorphism has been associated both with depression and aggression/hostility. The multidirectional association between depression, aggression and the s allele may be important, since all these phenomena are related to suicidal behavior. Our aim was to investigate the association between 5-HTTLPR and aggressive/hostile traits in depressed patients and controls.

METHODS

137 depressive and 118 control women completed the Buss-Durkee Hostility Inventory and were genotyped for 5-HTTLPR. BDHI scores in the different groups were investigated by Generalized Linear Model Analysis. Association between dependent and independent variables in the model was tested by the likelihood ratio Chi-square statistic.

RESULTS

Diagnosis and genotype showed a significant association with several aggressive/hostile traits. Interaction of the two main effects was also significant in case of several subscales. Post hoc analyses indicated a significant association between BDHI subscales and s allele only in the depressed group.

LIMITATION

Only women were studied and since gender differences are present both in aggressive behavior and putatively in the behavioral effects of 5-HTTLPR genotype, our findings pertain only to females.

CONCLUSION

Our results indicate a robust relationship between aggression/hostility and 5-HTTLPR genotype, but this association is more marked in the presence of depression. The presence of the s allele thus not only contributes to a higher risk of depression, but in depressives also leads to higher aggression/hostility. Our results have important implications for suicide research, since the s allele is associated with violent suicide, and this association may be mediated through the emergence of increased aggression/hostility in depressed patients carrying the s allele.

Epigenetics in Developmental Disorder: ADHD and Endophenotypes

Heterogeneity in attention-deficit/hyperactivity disorder (ADHD), with complex interactive operations of genetic and environmental factors, is expressed in a variety of disorder manifestations: severity, co-morbidities of symptoms, and the effects of genes on phenotypes. Neurodevelopmental influences of genomic imprinting have set the stage for the structural-physiological variations that modulate the cognitive, affective, and pathophysiological domains of ADHD. The relative contributions of genetic and environmental factors provide rapidly proliferating insights into the developmental trajectory of the condition, both structurally and functionally. Parent-of-origin effects seem to support the notion that genetic risks for disease process debut often interact with the social environment, i.e., the parental environment in infants and young children. The notion of endophenotypes, markers of an underlying liability to the disorder, may facilitate detection of genetic risks relative to a complex clinical disorder. Simple genetic association has proven insufficient to explain the spectrum of ADHD. At a primary level of analysis, the consideration of epigenetic regulation of brain signalling mechanisms, dopamine, serotonin, and noradrenaline is examined. Neurotrophic factors that participate in the neurogenesis, survival, and functional maintenance of brain systems, are involved in neuroplasticity alterations underlying brain disorders, and are implicated in the genetic predisposition to ADHD, but not obviously, nor in a simple or straightforward fashion. In the context of intervention, genetic linkage studies of ADHD pharmacological intervention have demonstrated that associations have fitted the "drug response phenotype," rather than the disorder diagnosis. Despite conflicting evidence for the existence, or not, of genetic associations between disorder diagnosis and genes regulating the structure and function of neurotransmitters and brain-derived neurotrophic factor (BDNF), associations between symptoms-profiles endophenotypes and single nucleotide polymorphisms appear reassuring.