Impulsiveness, serotonin genes and repetition of deliberate self-harm (DSH)

Anger and impulsiveness in migraine patients with and without aura

Background and purpose: Migraine is a common primary headache disorder triggered by internal or external stimuli. Impulsitivity and anger are associated with many neurological and psychiatric disorders. The aim of this study was to investigate the anger and impulsivity in migraine patients with or without aura.Methods: A total of 55 patients aged between 18 and 55, who were diagnosed with episodic migraine (31 with aura and 24 without aura) and 40 healthy controls were enrolled in this prospective cross-sectional study.Migraine diagnosis and classification were based on criteria from the International Classification of Headache Disorders, 3rd edition (beta version). Multidimensional Anger Scale and Barratt Impulsivity Scale-11 were administered to the patient and control groups.Results:Migraine patients with aura, migraine patients without aura and control groups were compared, anger symptoms were significantly higher in migraine patients with aura (p < 0.001), but between these groups there was no significant difference in terms of impulsivity (p = 0.711).Conclusions: It was found that anger symptoms were more common in migraine patients with aura compared to migraine patients without aura and control group, but in impulsitivity there was no difference between groups.Further studies in future investigating the relation between migraine with aura and anger may pave the way for different and more specified treatment approach.

The Finno-Ugrian Suicide Hypothesis: Variation in European Suicide Rates by Latitude and Longitude

The marked variation regarding the suicide rate in 34 European countries is well described by regressing the national suicide rate on the capital cities' latitudes and on an interaction term of squared latitude multiplied with longitude. The interaction term explains 40.8% and 29.1% of men's and women's suicide rate, respectively, and latitude explains a further significant increment of 10.9% and 10.6% variance of men's and women's suicide rate, respectively. This regression model quantifies the Finno-Ugrian suicide hypothesis of Kondrichin and of Marušiš and Farmer. The European countries highest in suicide rate constitute a contiguous, J-shaped belt, spanning from Finland to Austria. This area maps onto the second principal component identified for European gene distribution, representing ancestral adaptation to cold climates and the Uralic language dispersion. Thus, population differences in genetic risk factors may account for the spatial pattern in European suicide rates.

Aggressive behavior in humans: Genes and pathways identified through association studies

Aggressive behavior has both genetic and environmental components. Many association studies have been performed to identify genetic factors underlying aggressive behaviors in humans. In this review we summarize the previous work performed in this field, considering both candidate gene (CGAS) and genome-wide association studies (GWAS), excluding those performed in samples where the primary diagnosis is a psychiatric or neurological disorder other than an aggression-related phenotype. Subsequently, we have studied the enrichment of pathways and functions in GWAS data. The results of our searches show that most CGAS have identified associations with genes involved in dopaminergic and serotonergic neurotransmission and in hormone regulation. On the other hand, GWAS have not yet identified genome-wide significant associations, but top nominal findings are related to several signaling pathways, such as axon guidance or estrogen receptor signaling, and also to neurodevelopmental processes and synaptic plasticity. Future studies should use larger samples, homogeneous phenotypes and standardized measurements to identify genes that underlie aggressive behaviors in humans. © 2016 Wiley Periodicals, Inc.

Development and validation of empirically derived frequency criteria for NSSI disorder using exploratory data mining

Research suggesting nonsuicidal self-injury (NSSI) may belong in a distinct diagnostic category has led to the inclusion of NSSI disorder in the DSM-5 section for future study. There has been limited research, however, examining the validity of Criterion A (the frequency criterion). The current study aimed to examine the validity of the frequency criterion of NSSI disorder through the use of an exploratory data mining method, structural equation modeling trees, as a way to determine a NSSI frequency that optimally discriminates pathological NSSI from normative behavior among undergraduate students (n = 3,559), 428 who engaged in NSSI in the previous year. The model included psychopathology symptomology found to be comorbid with NSSI and cognitive-affective deficits commonly associated with NSSI. Results demonstrated a first split between individuals with 0 and 1 act of NSSI in the past year, as was expected. Among individuals with 1 or more previous acts, the optimal split was between those with 5 and 6 NSSI acts in the past year. Results from the current study suggest that individuals with 6 acts of NSSI in past year, compared with those with 5 acts or less, may represent a more severe group of self-injurers. These individuals reported higher levels of related psychopathology symptomology and cognitive-affective deficits, in addition to decreased quality of life. Findings have potential implications for the proposed frequency criteria of NSSI disorder and how pathological NSSI is characterized. (PsycINFO Database Record

5-HT2C receptors in psychiatric disorders: A review

5-HT2Rs have a different genomic organization from other 5-HT2Rs. 5HT2CR undergoes post-transcriptional pre-mRNA editing generating diversity among RNA transcripts. Selective post-transcriptional editing could be involved in the pathophysiology of psychiatric disorders through impairment in G-protein interactions. Moreover, it may influence the therapeutic response to agents such as atypical antipsychotic drugs. Additionally, 5-HT2CR exhibits alternative splicing. Central serotonergic and dopaminergic systems interact to modulate normal and abnormal behaviors. Thus, 5HT2CR plays a crucial role in psychiatric disorders. 5HT2CR could be a relevant pharmacological target in the treatment of neuropsychiatric disorders. The development of drugs that specifically target 5-HT2C receptors will allow for better understanding of their involvement in the pathophysiology of psychiatric disorders including schizophrenia, anxiety, and depression. Among therapeutic means currently available, most drugs used to treat highly morbid psychiatric diseases interact at least partly with 5-HT2CRs. Pharmacologically, 5HT2CRs, have the ability to generate differentially distinct response signal transduction pathways depending on the type of 5HT2CR agonist. Although this receptor property has been clearly demonstrated, in vitro, the eventual beneficial impact of this property opens new perspectives in the development of agonists that could activate signal transduction pathways leading to better therapeutic efficiency with fewer adverse effects.

Interpersonal processes and self-injury: a qualitative study using Bricolage

INTRODUCTION

Literature on self-injury has recognized the impact on the relationship between clients and staff.

RATIONALE

There is an absence of a detailed account of interpersonal processes surrounding self-injury.

AIM

A Bricolage qualitative research approach was carried out in the United Kingdom that explored the interpersonal processes surrounding self-injury.

METHOD

Three pairs of clients and staff were interviewed about an incident of self-injury. The interviews were thematically analysed and then synthesized producing a deeper exploration of the relationship between the client and staff.

FINDINGS

An interpersonal trigger followed by anger and shame, resulted in self-injury to 'numb' these experiences.

DISCUSSION

Self-injury is conceptualized as a safety behaviour to avoid shame and anger and then as a maintenance cycle that traps the client in a reinforcing and rejecting relationship. Staff interviewed were able to reflect with the clients and help them reframe these experiences.

IMPLICATIONS FOR PRACTICE

Mental Health Nurses can work with clients to understand their own interpersonal cycles of self-injury. They can then reflect on their own roles in this process and avoid reinforcing the clients' negative beliefs. WHAT THE STUDY ADDS TO INTERNATIONAL EVIDENCE: This is the first international paper to explore the interconnection between the client and a professional helper in their lived experiences of self-injury.

Genetics of aggressive behavior: An overview

The Research Domain Criteria (RDoC) address three types of aggression: frustrative non-reward, defensive aggression and offensive/proactive aggression. This review sought to present the evidence for genetic underpinnings of aggression and to determine to what degree prior studies have examined phenotypes that fit into the RDoC framework. Although the constructs of defensive and offensive aggression have been widely used in the animal genetics literature, the human literature is mostly agnostic with regard to all the RDoC constructs. We know from twin studies that about half the variance in behavior may be explained by genetic risk factors. This is true for both dimensional, trait-like, measures of aggression and categorical definitions of psychopathology. The non-shared environment seems to have a moderate influence with the effects of shared environment being unclear. Human molecular genetic studies of aggression are in an early stage. The most promising candidates are in the dopaminergic and serotonergic systems along with hormonal regulators. Genome-wide association studies have not yet achieved genome-wide significance, but current samples are too small to detect variants having the small effects one would expect for a complex disorder. The strongest molecular evidence for a genetic basis for aggression comes from animal models comparing aggressive and non-aggressive strains or documenting the effects of gene knockouts. Although we have learned much from these prior studies, future studies should improve the measurement of aggression by using a systematic method of measurement such as that proposed by the RDoC initiative.

Self-regulatory failure and the perpetration of adolescent dating violence: Examining an alcohol use by gene explanation

Studies report that alcohol use is related to partner violence, but for many, alcohol use does not culminate in violence against partners. Guided by a self-regulatory failure framework, we predicted that alcohol use would be more strongly associated with dating violence perpetration among adolescents with genotypes linked to impulsivity and emotional reactivity. The hypothesis was tested using random coefficient modeling of data from a multi-wave longitudinal study spanning grades 8-12 (ages 13-18) (n = 1,475). Analyses adjusted for multiple testing and race, and the potential for gene by environment correlation was examined. As predicted, alcohol use was more strongly associated with dating violence among adolescents who had a high rather than a low multilocus genetic profile composed of five genetic markers that influence dopamine signaling. Alcohol use was more strongly related to dating violence among boys with long rather than short 5-HTTLPR alleles, the opposite of the prediction. MAOA-uVNTR did not interact with alcohol, but it had a main effect on dating violence by boys in later grades in the expected direction: boys with more low activity alleles perpetrated more dating violence. Exploratory analyses found variation in findings by race. Our findings demonstrate the importance of incorporating genes into etiological studies of adolescent dating violence, which to date has not been done. Aggr. Behav. Aggr. Behav. 42:189-203, 2015. © 2014 Wiley Periodicals, Inc.

Suicidal ideation in underweight adults who attempt to lose weight: Korea national health and nutrition examination survey, 2007-2012

BACKGROUND

Being underweight has been related to health risks. However, little is known about the relationship between suicidal ideation and attempting to lose weight. This study was conducted to examine if there is an association between suicidal ideation and attempting to lose weight among underweight adults.

METHODS

A cross-sectional study of 1,122 underweight adults (range, 19 to 69 years) was conducted based on the Korea National Health and Nutrition Examination Survey, 2007-2012. We examined suicidal ideation, doctor-diagnosed depression, depressive mood, stress, physical activity, health-related behavior, comorbidity, and socioeconomic status by weight loss attempts. Logistic regression analysis was performed to examine the association between suicidal ideation and weight loss attempts. The following covariates were controlled for: age, sex, physical activity, alcohol problem, marital status, education, income, occupation, self-perception of body image, chronic disease, and body mass index.

RESULTS

There were 101 subjects in the weight loss attempt group and 1,021 in the non-attempt group. The attempt group had a higher risk of suicidal ideation (odds ratio [OR], 2.47; 95% confidence interval [CI], 1.35 to 4.53) and depressive symptoms (OR, 2.17; 95% CI, 1.19 to 3.98). After depressive symptoms were added to the covariates, the risk of suicidal ideation was also significant (OR 2.11, 95% CI: 1.03 to 4.35). The two groups did not significantly differ in doctor-diagnosed depression and stress.

CONCLUSION

Weight loss attempts were associated with suicidal ideation in underweight Korean adults.

Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior

Serotonin regulates a wide variety of brain functions and behaviors. Here, we synthesize previous findings that serotonin regulates executive function, sensory gating, and social behavior and that attention deficit hyperactivity disorder, bipolar disorder, schizophrenia, and impulsive behavior all share in common defects in these functions. It has remained unclear why supplementation with omega-3 fatty acids and vitamin D improve cognitive function and behavior in these brain disorders. Here, we propose mechanisms by which serotonin synthesis, release, and function in the brain are modulated by vitamin D and the 2 marine omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Brain serotonin is synthesized from tryptophan by tryptophan hydroxylase 2, which is transcriptionally activated by vitamin D hormone. Inadequate levels of vitamin D (∼70% of the population) and omega-3 fatty acids are common, suggesting that brain serotonin synthesis is not optimal. We propose mechanisms by which EPA increases serotonin release from presynaptic neurons by reducing E2 series prostaglandins and DHA influences serotonin receptor action by increasing cell membrane fluidity in postsynaptic neurons. We propose a model whereby insufficient levels of vitamin D, EPA, or DHA, in combination with genetic factors and at key periods during development, would lead to dysfunctional serotonin activation and function and may be one underlying mechanism that contributes to neuropsychiatric disorders and depression. This model suggests that optimizing vitamin D and marine omega-3 fatty acid intake may help prevent and modulate the severity of brain dysfunction.

Optimal Implementation of Intervention to Control the Self-harm Epidemic

Objectives

Deliberate self-harm (DSH) of a young person has been a matter of growing concern to parents and policymakers. Prevention and early eradication are the main interventional techniques among which prevention through reducing peer pressure has a major role in reducing the DSH epidemic. Our aim is to develop an optimal control strategy for minimizing the DSH epidemic and to assess the efficacy of the controls.

Methods

We considered a deterministic compartmental model of the DSH epidemic and two interventional techniques as the control measures. Pontryagin's Maximum Principle was used to mathematically derive the optimal controls. We also simulated the model using the forward-backward sweep method.

Results

Simulation results showed that the controls needed to be used simultaneously to reduce DSH successfully. An optimal control strategy should be adopted, depending on implementation costs for the controls.

Conclusion

The long-term success of the optimum control depends on the implementation cost. If the cost is very high, the control could be used for a short term, even though it fails in the long run. The control strategy, most importantly, should be implemented as early as possible to attack a comparatively fewer number of addicted individuals.

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.

Systematic meta-analyses and field synopsis of genetic association studies of violence and aggression

A large number of candidate gene studies for aggression and violence have been conducted. Successful identification of associations between genetic markers and aggression would contribute to understanding the neurobiology of antisocial behavior and potentially provide useful tools for risk prediction and therapeutic targets for high-risk groups of patients and offenders. We systematically reviewed the literature and assessed the evidence on genetic association studies of aggression and related outcomes in order to provide a field synopsis. We searched PubMed and Huge Navigator databases and sought additional data through reviewing reference lists and correspondence with investigators. Genetic association studies were included if outcome data on aggression or violent behavior either as a binary outcome or as a quantitative trait were provided. From 1331 potentially relevant investigations, 185 studies constituting 277 independent associations on 31 genes fulfilled the predetermined selection criteria. Data from variants investigated in three or more samples were combined in meta-analyses and potential sources of heterogeneity were investigated using subgroup analyses. In the primary analyses, which used relaxed inclusion criteria, we found no association between any polymorphism analyzed and aggression at the 5% level of significance. Subgroup analyses, including by severity of outcome, age group, characteristics of the sample and ethnicity, did not demonstrate any consistent findings. Current evidence does not support the use of such genes to predict dangerousness or as markers for therapeutic interventions.

Sleep problems and hospitalization for self-harm: a 15-year follow-up of 9,000 Norwegian adolescents. The Young-HUNT Study

OBJECTIVES

To investigate the association between sleeping problems in adolescence and subsequent hospital admission for self-harm (SH).

DESIGN

Prospective cohort study, linking health survey information on sleep problems to hospital-based patient records.

SETTING

Residents of Nord-Trøndelag County, Norway, aged 13-19 years in 1995-97.

PATIENTS OR PARTICIPANTS

10,202 adolescents were invited to participate in the Young-HUNT study; 8,983 (88%) completed the health survey.

MEASUREMENTS AND RESULTS

10% of participants reported difficulties initiating sleep, 4% reported early morning wakening. Ninety-eight participants (27% male) were hospitalized following SH over a mean 12 years follow-up. Difficulties initiating sleep/early morning wakening were associated with increased risk of SH (HR 2.11, 95% CI 1.29-3.46, sex- and age-adjusted) compared with no problems, yet coexistent symptoms of combined anxiety/depression explained most of the association with sleep problems (fully adjusted HR 1.19, 95% CI 0.66-2.16). The HR of combined difficulties initiating sleep/early morning wakening differed in those with and without anxiety/depression at baseline (P interaction = 0.03); among those without caseness symptoms of anxiety/depression it was 5.58 (95% CI 2.02-15.40), while in those with caseness symptoms of anxiety/ depression it was 0.82 (95% CI 0.19-3.44).

CONCLUSIONS

Sleep problems are common among Norwegian adolescents. The strong association between sleep problems and subsequent hospitalization for self-harm could mainly be related to coexistent symptoms of anxiety and depression. Prevention of adolescent sleep problems, anxiety and depression should be targeted when seeking to reduce and prevent self-harm.

Risk factors for repetition of self-harm: a systematic review of prospective hospital-based studies

BACKGROUND

Self-harm entails high costs to individuals and society in terms of suicide risk, morbidity and healthcare expenditure. Repetition of self-harm confers yet higher risk of suicide and risk assessment of self-harm patients forms a key component of the health care management of self-harm patients. To date, there has been no systematic review published which synthesises the extensive evidence on risk factors for repetition.

OBJECTIVE

This review is intended to identify risk factors for prospective repetition of self-harm after an index self-harm presentation, irrespective of suicidal intent.

DATA SOURCES

PubMed, PsychInfo and Scirus were used to search for relevant publications. We included cohort studies which examining factors associated with prospective repetition among those presenting with self-harm to emergency departments. Journal articles, abstracts, letters and theses in any language published up to June 2012 were considered. Studies were quality-assessed and synthesised in narrative form.

RESULTS

A total of 129 studies, including 329,001 participants, met our inclusion criteria. Some factors were studied extensively and were found to have a consistent association with repetition. These included previous self-harm, personality disorder, hopelessness, history of psychiatric treatment, schizophrenia, alcohol abuse/dependence, drug abuse/dependence, and living alone. However, the sensitivity values of these measures varied greatly across studies. Psychological risk factors and protective factors have been relatively under-researched but show emerging associations with repetition. Composite risk scales tended to have high sensitivity but poor specificity.

CONCLUSIONS

Many risk factors for repetition of self-harm match risk factors for initiation of self-harm, but the most consistent evidence for increased risk of repetition comes from long-standing psychosocial vulnerabilities, rather than characteristics of an index episode. The current review will enhance prediction of self-harm and assist in the efficient allocation of intervention resources.

Affective temperaments and self-harm in adolescents: a cross-sectional study from a community sample

BACKGROUND

Adolescent self-harm (SH) is a major health problem potentially associated with poor outcomes including reduced life expectancy and risk of completed suicide in adulthood. Several studies point to the role of possible constitutional vulnerabilities that could predispose to this behavior. This study sets out to assess the relationship between SH and affective temperaments (AT) in adolescents.

METHODS

A cross-sectional sample of public school students (n=1713), with age limits between 12 and 20, was examined using anonymously completed self-report instruments including 'The Lifestyle & Coping Questionnaire' and the 'Temperament Evaluation of Memphis, Pisa, Paris and San Diego-auto-questionnaire' (TEMPS-A). SH was defined according to strict criteria through a two-stage procedure. Statistical significance of associations with SH for categorical variables was assessed in bivariate analysis. AT predictors of lifetime SH were examined in multivariate logistic regression analyses.

RESULTS

Lifetime SH was reported by 7.3%, being about three times more frequent in females. SH was associated, in both genders, with a significant deviation on depressive, cyclothymic and irritable dimensions of TEMPS-A. After multivariate logistic regression adjusted to family typology, smoking status, alcohol and drug consumption, only depressive temperament remained significantly associated as a predictor of SH in both genders.

LIMITATIONS

The use of self-rating instruments and the cross-sectional nature of the study limit our results.

CONCLUSIONS

Cyclothymic, irritable and especially depressive temperament might represent an important marker of vulnerability to SH in both male and female adolescents.

Risk factors for fatal and nonfatal repetition of suicide attempts: a literature review

OBJECTIVES

This review aimed to identify the evidence for predictors of repetition of suicide attempts, and more specifically for subsequent completed suicide.

METHODS

We conducted a literature search of PubMed and Embase between January 1, 1991 and December 31, 2009, and we excluded studies investigating only special populations (eg, male and female only, children and adolescents, elderly, a specific psychiatric disorder) and studies with sample size fewer than 50 patients.

RESULTS

The strongest predictor of a repeated attempt is a previous attempt, followed by being a victim of sexual abuse, poor global functioning, having a psychiatric disorder, being on psychiatric treatment, depression, anxiety, and alcohol abuse or dependence. For other variables examined (Caucasian ethnicity, having a criminal record, having any mood disorders, bad family environment, and impulsivity) there are indications for a putative correlation as well. For completed suicide, the strongest predictors are older age, suicide ideation, and history of suicide attempt. Living alone, male sex, and alcohol abuse are weakly predictive with a positive correlation (but sustained by very scarce data) for poor impulsivity and a somatic diagnosis.

CONCLUSION

It is difficult to find predictors for repetition of nonfatal suicide attempts, and even more difficult to identify predictors of completed suicide. Suicide ideation and alcohol or substance abuse/dependence, which are, along with depression, the most consistent predictors for initial nonfatal attempt and suicide, are not consistently reported to be very strong predictors for nonfatal repetition.

Interaction between tryptophan hydroxylase I polymorphisms and childhood abuse is associated with increased risk for borderline personality disorder in adulthood

INTRODUCTION

Borderline personality disorder (BPD) is a severe disorder with high morbidity and mortality, but unknown etiology. Childhood abuse has been proposed as an etiological factor, but the mechanism by which an abuse history could influence the risk for BPD has not been determined. The aim of this study was to determine whether the tryptophan hydroxylase 1 (TPH1) gene is related to BPD in a clinical sample, and whether TPH1 genotypes or haplotypes moderate the relationship between abuse history and BPD.

METHODS

Three hundred and ninety-eight patients diagnosed with mood disorders were genotyped for TPH1 G-6526A promoter polymorphism (rs4537731) and the A218C intron 7 polymorphism (rs1800532) and a set of ancestry informative markers, assessed for Diagnostic and Statistical Manual of Mental Disorders, 4th edition diagnoses, and assessed for a history of physical and sexual abuse.

RESULTS

Patients with a diagnosis of BPD were more likely to be risk allele carriers (A alleles at both loci) than the non-BPD group. Logistic regression analysis predicting BPD diagnosis with both single-nucleotide polymorphisms and haplotypes showed significant interaction effects between genotype and abuse history. Poisson regression predicting the number of BPD diagnostic criteria met with the same predictor set also included a significant interaction term. Risk allele carriers with a history of abuse had an increased likelihood of a BPD diagnosis.

CONCLUSION

Variation in TPH1 may increase risk for developing BPD as a result of childhood abuse. Elements of BPD pathology may be due in part to a genetically influenced serotonergic dysfunction, which in turn may lead to a differential response to environmental stressors.

The role of depressive symptoms, family invalidation and behavioral impulsivity in the occurrence and repetition of non-suicidal self-injury in Chinese adolescents: a 2-year follow-up study

This study used zero-inflated poisson regression analysis to examine the role of depressive symptoms, family invalidation, and behavioral impulsivity in the occurrence and repetition of non-suicidal self-injury among Chinese community adolescents over a 2-year period. Participants, 4782 high school students, were assessed twice during the follow-up period. Results indicate that while Year 1 depressive symptoms and family invalidation were significantly associated with the occurrence of Year 2 NSSI, Year 1 behavioral impulsivity contributed to both the occurrence and repetition of Year 2 NSSI. Findings of this study suggest that adolescents who display multiple impulsive behaviors may be at particular risk for engaging in repetitive NSSI. Clinical implications of these findings and future research directions were discussed.

TPH1 is associated with major depressive disorder but not with SSRI/SNRI response in Taiwanese patients

RATIONALE

Tryptophan hydroxylase 1 (TPH1), which encodes the rate-limiting enzyme tryptophan hydroxylase in the biosynthesis of serotonin, is a candidate gene in the development and treatment response of major depressive disorder (MDD); however, its actual role is uncertain.

OBJECTIVES

We aimed to compare the allele frequencies of TPH1 in MDD patients and healthy controls in Taiwan, and also to investigate the association between TPH1 A218C and treatment response to either fluoxetine or venlafaxine in a Taiwanese population with MDD.

METHODS

One hundred five healthy controls and 115 outpatients diagnosed with MDD were recruited and genotyped for the TPH1 218A/C (rs1800532) polymorphism. Patients were randomized into either the fluoxetine or venlafaxine treatment group. The 21-item Hamilton rating scale for depression (HAM-D) was administered to evaluate depressive symptoms at baseline and bi-weekly over 6 weeks of treatment.

RESULTS

The TPH1 218A/C allele frequencies differed significantly between healthy controls and MDD patients in Taiwan, with a higher prevalence of the A allele in the patient group (p = 0.025). The odds ratio of the A allele to the C allele was 0.507 for the subjects with MDD. There was no significant correlation between the percentage change in HAM-D score and either TPH1 218A/C genotype or TPH1 allele frequencies.

CONCLUSIONS

This study indicated that the TPH1 218A/C genotype and allele frequencies differed between the Taiwanese healthy controls and MDD patients but could not be used to predict treatment outcome in Taiwanese MDD patients. Further research with larger sample sizes is needed to confirm the role of TPH1 218A/C.

The construction of self-injury in the clinical literature: a sociological exploration

This article presents a sociologically informed critique of a range of academic literatures relating to self-injury. It is noted how a lack of consensus on definitional issues, together with the inaccurate portrayal of the "typical self-injurer" in the clinical literature, has impeded the development of a sound understanding of self-injury. Some of the more problematic explanations for self-injury are explored. The individualistic focus of existing research is found to be inadequate, since it fails to account for the social context in which self-injury occurs. Social scientific approaches critically examine psychiatric and psychological constructions of self-injury, explore wider social and cultural meanings of the behavior, and examine its distribution across different social groups. The inclusion of social scientific perspectives into current debates will greatly improve understanding of self-injury.

Further exploration of the possible influence of polymorphisms in HTR2C and 5HTT on body weight

Receptors of the 5-HT2C subtype are of importance for the influence of serotonin on food intake, and 2 single nucleotide polymorphisms in this gene (HTR2C)--Cys23Ser (rs6318) and -759C>T (rs3813929)--have been reported to be associated with weight and/or antipsychotic-induced weight gain. The present study aimed to replicate these associations; in addition, the 5-HTTLPR polymorphism in the promoter region of the serotonin transporter gene (SLC6A4) was assessed. The polymorphisms were genotyped in subjects recruited from the normal population (n = 510), and possible associations between genotype and body mass index (BMI) were assessed. The Ser23 allele was more common in underweight subjects (BMI <20) than in normal- and overweight (BMI > or =20) subjects (P = .006). The T allele of the -759C/T polymorphism was less common in the overweight group (BMI > or =25) (P = .007). Homozygosity for the short allele of 5-HTTLPR was more frequent in underweight subjects (P = .015). Our results are in agreement with previous studies, suggesting polymorphisms in HTR2C to be associated with body weight, particularly in women; and they also suggest that 5-HTTLPR may influence this phenotype. Further studies on the importance of the investigated genes for eating disorders and drug-induced weight gain are warranted.

Fluoxetine response in impulsive-aggressive behavior and serotonin transporter polymorphism in personality disorder

BACKGROUND

Disturbances in central serotonin function have been implicated in impulsive and aggressive behavior. A deletion/insertion polymorphism within the 5-HT transporter promoter gene (5-HTTLPR) is thought to be associated with disturbed impulse control, anxiety, and depression. The serotonin transporter (5-HTT) is the primary action site for selective serotonin reuptake inhibitors (SSRIs). Several studies of major depression have shown that the l allele of 5-HTTLPR is associated with better SSRI antidepressant effects than the s allele.

METHODS

This study investigates the association between response of impulsivity to treatment with fluoxetine and 5-HTTLPR polymorphism in 49 personality disordered patients. Additionally, we studied TPH1, 5HT1B and 5HT2C receptor polymorphisms as predictors of response in this population.

RESULTS

Results reveal that patients with the l/l genotype of 5-HTTLPR had a significantly better response to fluoxetine when compared to s allele carriers, as evaluated on the basis of total (P<0.05) and Aggression subscale (P<0.01) Overt Aggression Scale Modified-score percentage change. There were no significant associations between fluoxetine response and TPH1 (A218C) (-6525 A>G) (-5806 G>T), HTR1B (G861C) and HTR2C (G68C) genotype groups.

CONCLUSION

This is the first study assessing the association between these polymorphisms and anti-impulsive response to fluoxetine in personality disorder. As the s genotype is associated with a poorer selective serotonin reuptake inhibitors response in major depression, bulimia nervosa and borderline personality disorder, it could represent a common biological background for SSRI response.

Are self-injurers impulsive?: Results from two behavioral laboratory studies

Common clinical wisdom suggests that people who engage in self-injury are impulsive. However, virtually all prior work in this area has relied on individuals' self-report of impulsiveness, despite evidence that people are limited in their ability to accurately report on cognitive processes that occur outside awareness. To address this knowledge gap, we used performance-based measures of several dimensions of impulsiveness to assess whether people engaging in non-suicidal self-injury (NSSI) demonstrate greater impulsiveness than non-injurers. In Study 1, we compared adolescent self-injurers (n=64) to age-, sex-, and race/ethnicity-matched, non-injurious controls (n=30) on self-reported impulsiveness (Schedule for Affective Disorders and Schizophrenia for School Age Children, Present and LifetimeVersion) and on performance-based measures of two dimensions of impulsiveness: behavioral disinhibition (Conners' Continuous Performance Test) and risky decision-making (Iowa Gambling Task). In Study 2, we compared adult female self-injurers (n=20) with age- and race/ethnicity-matched, non-injurious controls (n=20) on self-reported impulsiveness (Barratt Impulsiveness Scale-11), and performance-based measures of behavioral disinhibition, risky decision-making, and two measures of delay discounting. In both studies, self-injurers reported greater impulsiveness; however, performance-based measures of impulsiveness failed to detect any between-group differences. We propose several potential explanations for the discrepancies observed between self-report and performance-based measures of impulsiveness and discuss directions for future research on impulsiveness and self-injury.

Personality and non-suicidal deliberate self-harm: Trait differences among a non-clinical population

Limited information is available on understanding why particular individuals engage in non-suicidal deliberate self-harm (DSH), especially among non-clinical populations. An array of personality traits, such as those included in the five-factor model of personality, may further an understanding of DSH. The purpose of this study was to examine personality traits among non-clinical groups with or without a history of DSH. College students (N=238) completed self-report measures of DSH and personality. Both multivariate (MANOVA, discriminant analysis) and univariate (ANOVA) statistical procedures supported the hypothesis that those with a history of DSH (n=59) had significantly higher levels of neuroticism and openness to experience, and significantly lower levels of agreeableness and conscientiousness. Contrary to expectations, there were no differences in extraversion between the two groups. These results indicate personality differences among those with a history of DSH, which with additional research, may prove to be risk factors or targets of intervention for future DSH or collateral problems.

Impact of the tryptophan hydroxylase 1 gene A218C polymorphism on amygdala activity in response to affective facial stimuli in patients with major depressive disorder

Tryptophan hydroxylase-1 (TPH1) is the rate-limiting enzyme in serotonin biosynthesis, and allelic variations at the TPH1 locus have been implicated in the pathophysiology of depression. Using 1.5-Tesla functional magnetic resonance imaging, we investigated the possible relationship between TPH1 A218C polymorphism and amygdala response to negative facial stimuli in 26 right-handed female subjects with major depressive disorder (MDD). Genotyping was performed with the polymerase chain reaction. We found a significant association between A allele of the TPH1 A218C polymorphism and neural activations in response to negative facial stimuli. Subjects with the A allele of the TPH1 A218C polymorphism showed greater brain activity in the bilateral amygdala under the sad vs. the neutral condition compared with subjects homozygous for the C allele. Our results suggest that the A218C polymorphism of the TPH1 gene serves as a modulator of amygdala activity in patients with MDD.

The tryptophan hydroxylase-1 A218C polymorphism is associated with diagnosis, but not suicidal behavior, in borderline personality disorder

While there is some preliminary evidence that the tryptophan hydroxylase I (TPH1) polymorphisms are related to Borderline Personality Disorder (BPD), it is not clear if this association is due to the high rates of suicidal behavior in this patient group. Because of the reported association between TPH1 polymorphisms and suicidal behavior, determining whether TPH1 is related to BPD independent of suicidal behavior is of particular importance. One hundred patients diagnosed with BPD and 101 healthy controls were genotyped for TPH1 intron 7 A218C polymorphism and assessed for impulsiveness and hostility. The BPD patient group had a higher frequency of A allele carriers (AA/AC genotypes) than the control group (chi(2) = 6.12, df = 1, P = 0.01), and differed by genotype frequencies (P = 0.03). Suicide attempter status in the patient group was not related to genotype. Logistic regression analysis controlling for age and gender predicted BPD diagnosis from TPH1 allele group (AA/AC vs. CC, P = 0.03), and TPH1 heterozygotes (AC) appeared to have the highest risk for BPD (P = 0.03). In the full sample, participants with the AC genotype had higher impulsiveness and hostility scores. However, TPH1 did not predict these traits in either of the groups independently, suggesting the association may be an artifact of the association between TPH1 and BPD. Results suggest that the A allele of the tryptophan hydroxylase-1 A218 polymorphism may be associated with BPD, and that it does not appear to be related to suicidal behavior in this population. An aspect of BPD pathology may be due to serotonergic dysfunction.

Opposing effects of 5-HT(2A) and 5-HT(2C) receptor antagonists in the rat and mouse on premature responding in the five-choice serial reaction time test

RATIONALE

Serotonin (5-HT) has been linked to impulsivity with recent data suggesting that different receptor sub-types exert opposing influences on this behaviour.

OBJECTIVES

This work characterised the effects of 5-HT(2A) (ketanserin, (+/-)2,3-dimethoxyphenyl-1-[2-4-(piperidine)-methanol] [M100907]), 5-HT(2B) (6-chloro-5-methyl-1-(5-quinolylcarbamoyl) indoline [SB215505]) and 5-HT(2C) (6-chloro-5-methyl-1-[2-(2-methylpyridyl-3-oxy)-pyrid-5-yl carbomyl] indoline [SB242084]) receptor antagonists on impulsive behaviour, measured in the five-choice serial reaction time test (5CSRTT), in rats and mice. The effects of (+/-)-2,5-dimethoxy-4-iodoamphetamine (DOI) and (S)-2-(chloro-5-fluoro-indol-1-yl)-1-methylethylamine 1:1 C4H4O4 (Ro60-0175), two compounds that have been used extensively as agonists for the 5-HT(2A) and 5-HT(2C) receptor, were also measured.

MATERIALS AND METHODS

Rats and mice were trained on the 5CSRTT in which reinforcement is earned for detecting and correctly responding to brief presentations of a stimulus light. Impulsivity in this task is measured as premature responding, before stimulus presentation. Several variants of the task were used in which the inter-trial interval (ITI) length was manipulated to alter basal levels of premature responding.

RESULTS

In the rat, ketanserin and M100907 reduced and SB242084 enhanced premature responding. SB215505 had no effect. DOI generally disrupted responding, while Ro60-0175 reduced premature responding when a long ITI was used. In mice, M100907 reduced and SB242084 increased premature responding when the ITI was lengthened. The effects of these drugs on other aspects of performance were less robust. M100907 and ketanserin did not affect response accuracy but tended to slow speed of responding; SB242084 occasionally increased speed of responding and slightly reduced accuracy.

CONCLUSIONS

Serotonin exerts both excitatory and inhibitory influences on motor impulsivity via 5-HT(2A) and 5-HT(2C) receptors in both rats and mice.

Gonadal axis hormones in psychiatric male patients after a suicide attempt

Epidemiological and clinical studies support the view that aggressive acts like suicidal and violent behaviors share a common substrate. Certain aspects of violence in males have been related to high testosterone levels, but the relation of testosterone to attempted suicide has not been studied until now. We estimated plasma levels of testosterone (T), LH, and FSH in 80 male subjects after a suicide attempt and in whom a psychiatric assessment was done during their hospitalization. Suicide intent was evaluated in 72 subjects. A group of 56 healthy males in the same age range served as control. As a group, attempters showed significantly lower T levels, marginally higher LH, and normal FSH compared to controls. The attempters who used violent methods (26 subjects) had T levels even lower than the non-violent (drug overdose) subgroup. Comparisons of T levels of subgroups according to the (main) drug ingested (analgesics, benzodiazepines, antidepressants, neuroleptics, or other drugs) did not reveal any significant drug effect. In relation to diagnosis, the lowest T levels were found in the subgroup with schizophrenia (29 subjects). The T levels of this subgroup were also significantly lower compared to those of a group of 31 male schizophrenic patients, hospitalized and treated with neuroleptics. If the influence of post-attempt stress and medical condition on plasma T could be ruled out, low plasma T may prove to be a biological predictor of attempt, at least in male schizophrenic patients. Nevertheless, the findings differentiate suicidal behavior from other aggressive/violent behaviors and do not support the notion that suicidal and aggressive behaviors are manifestations of the same impulse.

Association between the tryptophan hydroxylase-1 gene A218C polymorphism and citalopram antidepressant response in a Korean population

Tryptophan hydroxylase-1 (TPH1) is the rate-limiting enzyme in serotonin biosynthesis, and selective serotonin reuptake inhibitors (SSRIs) exert their activity enhancing the general serotonergic tone. Citalopram is the most selective SSRI, with little or no affinity for a variety of receptor types. The goal of this study was to investigate whether the A218C polymorphism of the TPH1 gene is associated with the citalopram antidepressant response in subjects with major depressive disorder (MDD). All of the patients were evaluated using the 21-item Hamilton Depression Rating Scale before beginning and after 8 weeks of citalopram treatment. Genotyping was performed with the polymerase chain reaction. The remission rate to citalopram treatment was worse in MDD subjects with the TPH1 A/A and A/C genotypes than in those with the TPH1 C/C genotype. Our results suggest that the A218C polymorphism of the TPH1 gene serves as a modulator of antidepressant activity, especially in terms of treatment remission.

Tryptophan hydroxylase 1 gene haplotypes modify the effect of a hostile childhood environment on adulthood harm avoidance

We conducted a series of tests to determine whether there is any association between tryptophan hydroxylase 1 (TPH1) and temperament in adulthood. In addition to testing for main effects, we investigated whether TPH1 gene variation modifies the influence of childhood environment on temperament in adulthood. The subjects were 341 healthy adults whose childhood environment was assessed by their mothers in 1980 and who self-rated their temperaments twice, in 1997 and 2001. We found no association between the TPH1 gene and temperament; however, among women, the TPH1 gene modified a relationship between adverse childhood environment and harm avoidance in adulthood. This finding was confirmed in the same sample in another test setting 4 years later. The presence of the A/A haplotype of the TPH1 intron 7 A218A and A779C polymorphism predicted a high level of adulthood harm avoidance in the presence of a hostile childhood environment as defined in terms of emotional rejection, maternal neglect and harsh and inconsistent discipline. In addition, the findings suggest a gene-environment correlation for novelty seeking in men.

No association of 5-HT2C, 5-HT6, and tryptophan hydroxylase-1 gene polymorphisms with personality traits in the Japanese population

Serotonin 2C receptor (5-HT(2C)), serotonin 6 receptor (5-HT(6)), and tryptophan hydroxylase-1 (TPH1) genes could be candidates for personality-related genes considering the role of serotonin in various mental functions and behavior. However, a limited number of studies have investigated the association between these genes and personality traits. In the present study, we investigated the three serotonin-related genes, 5-HT(2C), 5-HT(6), and TPH1 genes, in relation to personality traits in the Japanese population. The Cys23Ser polymorphisms in the 5-HT(2C) gene, the 267T/C polymorphism of the 5-HT(6) gene, and the 779A/C polymorphisms in the TPH1 gene were genotyped in 253 healthy Japanese subjects. Personality traits were evaluated by using the Revised NEO Personality Inventory (NEO PI-R) and the State-Trait Anxiety Inventory (STAI). As a result, no significant association was observed between the polymorphisms and the NEO PI-R or the STAI scores. The present results did not provide evidence for the association between the three serotonin-related genes and personality traits. The genes might not have major role in the development of personality traits, although further investigation with larger sample size may be recommended for conclusion.

Temperament and character in mood disorders: influence of DRD4, SERTPR, TPH and MAO-A polymorphisms

Gene variants exert a complex range of effects on human normal and abnormal behavior. We previously reported the effect of gene variants in serotoninergic and dopaminergic pathways, in a range of clinical features in mood disorders, such as symptomathology, periodicity, social adjustment and treatment response. In this paper we hypothesized that the same gene variants could influence temperamental traits in mood disorders patients. We focused on genes of the serotoninergic and dopaminergic systems (dopamine receptor D4 gene, DRD4; serotonin transporter gene, promoter region SERTPR; tryptophan hydroxylase gene, TPH; monoamine oxidase A gene, MAO-A). Two hundred and seven euthymic subjects, affected by major depressive disorder (n=73) and bipolar disorder (n=134) were assessed by the Cloninger's Temperament and Character Inventory (TCI) and typed using PCR-based analyses. Possible stratification factors such as demographic, clinical and other temperamental factors were also taken into account. We observed that homozygosity for the short SERTPR allele was associated with low novelty-seeking scores (p=0.006) and genotypes containing the DRD4 long allele were marginally associated with low harm avoidance (p=0.05). Finally, the long MAO-A allele was associated with decreased persistence scores among females (p=0.006). Our observation of a pattern of influence on temperamental dimension exerted by serotonergic and dopaminergic genes suggests that the contribution of these polymorphisms to the clinical presentation of mood disorders could be mediated by an influence on personality differences.

No association between the tryptophan hydroxylase gene polymorphism and major depressive disorders and antidepressant response in a Korean population

The serotonergic neurotransmitter system has been implicated in major depressive disorder (MDD) and appears to be the target of a variety of antidepressants. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in serotonin biosynthesis, and selective serotonin re-uptake inhibitors exert their activity enhancing the general serotonergic tone. The goal of this study was to investigate whether the A218C polymorphism of the TPH gene is associated with MDD or antidepressant response. All patients were evaluated at the start and in the eighth week of using the 21-item Hamilton Depression Rating Scale. Genotyping was analyzed with polymerase chain reaction. There were no significant differences in genotypes and allele frequencies between the MDD patients (n = 93) and the control group (n = 127) and in the antidepressant response among TPH gene variants. Results suggest that the A218C polymorphism of the TPH gene does not play a major role in pathogenesis in MDD and does not serve as a modulator of antidepressant activity.

Season-of-birth as a risk factor for the seasonality of suicidal behaviour

Despite implicating the same biological systems, the relationship between suicide seasonality and season-of-birth has not been examined previously. The purpose of this study was to investigate the interaction between season-of-birth and the seasonality of suicidal behaviour. All adult suicides (N = 2923) and deliberate self harm (DSH) hospitalizations (N = 33321) in Western Australia (1970-96) were examined. A variable population at risk approach was used to determine season-of-birth. Seasonality was established by spectral analysis. We found that DSH has a significant season-of-birth (p = 0.047) and seasonality of occurrence, both peaking in spring. Individuals born in the 90 days centred on the peak birth period, however, show no DSH seasonality. In contrast, suicide has no season-of-birth (p = 0.53). We also found a season-of-birth effect among the DSH group that eliminates any seasonality of DSH among the high-risk by birth group. Further work is needed to identify the possible biological and environmental determinants of this interaction.

A comparison of multiple 5-HT receptors in two tasks measuring impulsivity

Impulsivity has often been assumed to be a unitary construct. However dissociable forms of impulsive behaviour may exist, each with distinct neurochemical underpinnings. To test this hypothesis, behavioural effects of three partially selective serotonergic (5-HT) ligands, ketanserin (5-HT2(A, C) receptor antagonist), SER-082 (5-HT2(C, B) receptor antagonist) and SB-270146-A (5-HT6 receptor antagonist) were compared in two tests of impulsivity. The five-choice serial reaction time task (5-csrtt) and a delayed reward task were chosen as they measure theoretically different types of impulsivity, behavioural inhibition versus choice preference for a delayed reward. Dissociation was seen between the effects of ketanserin, which decreased impulsivity in the 5-csrtt, but had no effect on the delayed reward task, and SER-082, which had no effect on the 5-csrtt, but decreased impulsive responding in the delayed reward task. SB-270146-A had no effect in either paradigm. The results suggest that the 5-csrtt and the delayed reward task do in fact measure different types of impulsive behaviour, which are at least partially neurochemically distinct.

Science and society: applications of behavioural genetics: outpacing the science?

Human behavioural genetics is an established research discipline of the genomic age, and applications for behavioural genetic information are most likely to emerge in areas such as criminal justice, education, employment and insurance. However, behavioural genetic research into personality traits and antisocial behaviour poses several risks; for example, tentative or preliminary research findings might be misused in legal and commercial settings. Scientific caution, public and media education, expert consultation and confidentiality protection are essential for the responsible use of behavioural genetics.

Sequencing of canine 5-hydroxytriptamine receptor (5-HTR) 1B, 2A, 2C genes and identification of polymorphisms in the 5-HTR1B gene

Polymorphisms of human genes encoding 5-hydroxytriptamine (serotonin) receptors (5-HTRs) are thought to be associated with psychiatric disorders and behavioral traits. In the present study, we searched for corresponding polymorphisms in the dog and compared allelic frequencies for the canine 5-HTR1B, 5-HTR2A, and 5-HTR2C genes among five canine breeds. The canine genes consisted of the following: 5-HTR1B, 1170 bp; 5-HTR2A, 1413 bp; and 5-HTR2C, 1377 bp. All of these genes were highly homologous with the human genes. We found six single nucleotide polymorphisms (SNPs) in the 5-HTR1B gene (G57A, A157C, G246A, C660G, T955C, and G1146C). Genotyping of the respective SNPs revealed that there were inter-breed variations in the genotypes and allelic frequencies for four out of the six identified SNPs, suggesting that further analyses of the polymorphisms of the 5-HTR1B gene would be useful in order to gain an understanding of the genetic background underlying the diversified behavioral traits among canine species.

5HT-2C receptor polymorphism in suicide victims. Association studies in German and Slavic populations

Sustainable observations suggest that suicidal behaviour by itself may have biological correlates, among which those related to the serotonergic synapse hold the key position. Based on the association of suicide and serotonergic dysfunction, it was proposed that genetic mechanisms affecting suicidal behaviour could be related to the alterations of the genes encoding the elements of 5HT synapse. The present study tested the association of the polymorphism in the serotonin 2C (5HT-2C) receptor coding region (Cys23Ser) with suicide commitment. Study was based on two independent samples, one of German (284 suicide victims versus 297 controls) and other of Slavic/Croatian (118 suicide victims versus 275 controls) ethnicity. No significant differences in allele or genotype frequencies between victims and controls were demonstrated. Results did not provide supporting evidence for the potential involvement of the investigated variants of 5HT-2C receptor in the susceptibility to suicide.

Defense styles, impulsivity and suicide attempts in major depression

BACKGROUND

The aim of our study was to identify if defense mechanisms are associated with impulsivity and lifetime suicide attempts in depressed patients.

SAMPLING AND METHODS

The Defense Style Questionnaire, the Impulsivity Rating Scale and the Impulse Control Scale were used in 77 depressed inpatients.

RESULTS

Impulsivity was correlated positively with immature and neurotic styles and negatively with mature style. Some but not all defense mechanisms were relevant in this respect. The number of lifetime suicide attempts was positively correlated not only with impulsivity, but also with immature style and to a lesser extent with neurotic style. Several defense mechanisms were involved in these correlations: undoing, projection, passive aggression, acting out, splitting and somatization.

CONCLUSIONS

Like impulsivity, defense styles may be relevant to discriminate recurrent suicide attempters in depression. Prospective assessment of defense styles and suicide attempts in depression is needed.

Understanding impulsivity in severe depression? A psychometrical contribution

BACKGROUND

Depression, especially severe depression, is strongly associated with suicidality. Impulsivity is one of the main dimensions of suicidality. The objective of this study was to assess the structure of impulsivity in severe depression and its relationships to suicide attempts.

METHODS

127 depressed in-patients were assessed at admission and after 4 weeks of treatment for depression and impulsivity with the Impulsivity Rating Scale (IRS) and the Impulse Control Scale (ICS) or the Baratt Impulsivity Scale (BIS).

RESULTS

Three dimensions of impulsivity were evidenced in these severely depressed patients, i.e., behavioral loss of control, nonplanning and cognitive. These three dimensions are state dependent. Recent suicide attempts in severe depression are related to loss of control and cognitive impulsivity but not to nonplanning. IRS ad ICS may assess primarily behavioral impulsivity, i.e., loss of control and nonplanning, whereas BIS may assess primarily cognitive impulsivity.

CONCLUSIONS

In the future, these three dimensions should be correlated to biological and genetic markers of impulsivity [serotonergic (5-HT) system] and prospective studies should assess the predictive value of the three dimensions of impulsivity in the occurrence of suicide attempts in depressed patients.

Molecular genetics in the analysis of suicide

Each year, one million people die of suicide. Among the different identified risk factors, genetic factors seem to be part of a multidimensional behavior, including psychiatric, psychosocial, biological factors and physical illness. Family studies have provided evidence for familial transmission in suicide, confirmed in twin and adoption studies. At a molecular level, serotonin seems to be one of the key neurotransmitters implicated in suicidal behavior. Therefore, genes coding for proteins involved in serotonergic neurotransmission have been extensively studied in case-control association studies on suicide. Major findings concern Tryptophan hydroxylase (TPH) gene, particularly in violent suicidal behavior. Though they may seem contradictory, studies on Serotonin transporter (5-HTT), Monaomine oxidase (MAOA), Serotonin 2A and 2C receptors (5-HT2A and 5-HT2C) and Tyrosine hydroxylase (TH) genes are promising. In spite of those observations having some limitations, it appears that genetic factors are a serious risk factor, besides environmental aspects of suicidal behavior.

Serotonin transporter polymorphisms and measures of impulsivity, aggression, and sensation seeking among African-American cocaine-dependent individuals

Considerable evidence indicates that serotonergic mechanisms, particularly the serotonin transporter (5HTT), may mediate central effects of cocaine and may also be involved in impulsive and aggressive behavior. We investigated whether polymorphisms in the 5HTT gene were related to traits of impulsivity, sensation seeking, and aggression among cocaine abusers. Standardized measures of these personality traits were obtained in a sample of 105 severely affected cocaine-dependent African-American subjects and 44 African-American controls. Two polymorphisms of the 5HTT gene were examined involving the 5' promoter (5HTTLPR) region and a 17 base pair variable-number-tandem-repeat (VNTR) marker among cocaine patients. No significant relationships were observed between polymorphic variants of the 5HTTLPR and VNTR regions and scores on any of the trait measures. Similarly, demographic variables and measures of severity of substance use and depression were unrelated to allele frequencies or genotype distributions of the variants among cocaine patients. As expected, cocaine patients scored significantly higher on total scores of impulsivity, aggression, and sensation seeking compared to controls. The findings do not seem to support an association between these polymorphisms in the 5HTT gene and impulsive-aggressive traits among cocaine-dependent African-American individuals.

Deliberate self-poisoning in Oman

OBJECTIVE

To describe the demographics, precipitating factors, substances and methods used for deliberate self-harm in Oman.

METHODS

Data were extracted from the Accident and Emergency (A & E) records of patients treated at the A & E units in Muscat from 1993 to 1998. Data were obtained form the history, and clinical findings resulting form deliberate self-harm.

RESULTS

During the 5-year study period, 123 persons presented to various hospitals in the Muscat area with injuries that resulted form deliberate self-harm. Most of these cases were women, students and unemployed. There was a high incidence of family, marital and psychiatric or social problems. The methods of self-harm were most often analgesics (such as paracetamol) and non-pharmaceutical chemicals.

CONCLUSIONS

The rate of self-injurious behaviour is low in Oman, compared with other countries, including other Islamic countries. The data illustrate a rising rate and a tendency to ingest toxic doses of analgesics or non-pharmaceutical chemicals.

Tryptophan hydroxylase gene associated with paroxetine antidepressant activity

The possible association of the A218C tryptophan hydroxylase (TPH) gene variant with the antidepressant activity of paroxetine was investigated in a sample of 121 inpatients affected by a major depressive episode and treated with paroxetine 20-40 mg with either placebo or pindolol in a double blind design for 4 weeks. The severity of depressive symptoms was weekly assessed with the Hamilton Rating Scale for Depression. TPH allelic variants were determined in each subject using a PCR-based technique. TPH*A/A and TPH*A/C variants were associated with a poorer response to paroxetine treatment when compared to TPH*C/C (P=0.005); this difference was not present in the pindolol augmented group. Other variables, such as sex, diagnosis, presence of psychotic features, severity of depressive symptomatology at baseline and paroxetine plasma level, were not associated with the outcome. TPH gene variants are therefore a possible modulator of paroxetine antidepressant activity.