Frequency Of Life Events Research Articles

Interactions between the vascular endothelial growth factor gene polymorphism and life events in susceptibility to major depressive disorder in a Chinese population

BackgroundRecent studies suggest that vascular endothelial growth factor (VEGF) is involved in the development of major depressive disorder. The aim of this study is to investigate the interaction between vascular endothelial growth factor (VEGF) polymorphism (+405G/C, rs2010963) and negative life events in the pathogenesis of major depressive disorder (MDD). MethodsDNA genotyping was performed on peripheral blood leukocytes in 274 patients with MDD and 273 age-and sex-matched controls. The frequency and severity of negative life events were assessed by the Life Events Scale (LES). A logistics method was employed to assess the gene-environment interaction (G×E). ResultsDifferences in rs2010963 genotype distributions were observed between MDD patients and controls. Significant G×E interactions between allelic variation of rs2010963 and negative life events were observed. Individuals carrying the C alleles were susceptible to MDD only when exposed to high-negative life events. ConclusionsThese results indicate that interactions between the VEGF rs2010963 polymorphism and environment increases the risk of developing MDD.

The Relationship Between Stressful Life Events and Axis I Diagnoses Among Adolescent Offspring of Probands With Bipolar and Non-Bipolar Psychiatric Disorders and Healthy Controls: The Pittsburgh Bipolar Offspring Study (BIOS).

Previous studies have explored the role of stressful life events in the development of mood disorders. We examined the frequency and nature of stressful life events as measured by the Stressful Life Events Schedule (SLES) among 3 groups of adolescent offspring of probands with bipolar (BD), with non-BD psychiatric disorders, and healthy controls. Furthermore, we examined the relationship between stressful life events and the presence of DSM-IV Axis I disorders in these offspring. Stressful life events were characterized as dependent, independent, or uncertain (neither dependent nor independent) and positive, negative, or neutral (neither positive nor negative). Offspring of probands with BD aged 13-18 years (n = 269), demographically matched offspring of probands with non-BD Axis I disorders (n = 88), and offspring of healthy controls (n = 81) from the Pittsburgh Bipolar Offspring Study were assessed from 2002 to 2007 with standardized instruments at intake. Probands completed the SLES for their offspring for life events within the prior year. Life events were evaluated with regard to current Axis I diagnoses in offspring after adjusting for confounds. After adjusting for demographic and clinical between-group differences (in probands and offspring), offspring of probands with BD had greater independent (χ² = 11.96, P < .04) and neutral (χ² = 17.99, P < .003) life events compared with offspring of healthy controls and greater number of more severe stressful life events than offspring of healthy controls, but not offspring of probands with non-BD. Offspring of BD probands with comorbid substance use disorder reported more independent stressful life events compared to those without comorbid substance use disorder (P = .024). Greater frequency and severity of stressful life events were associated with current Axis I disorder in offspring of both probands with BD and probands with other Axis I disorders regardless of dependency or valence. Greater frequency and severity of stressful life events were associated with greater current Axis I disorder in all offspring. Offspring of probands with BD have greater exposure to independent and neutral life events than offspring of healthy controls. Greater frequency and severity of stressful life events were associated with Axis I disorder in offspring of both BD and non-BD affected probands.

GNB3 and CREB1 gene polymorphisms combined with negative life events increase susceptibility to major depression in a Chinese Han population.

BackgroundMajor depression (MD) is caused by a combination of genetic and environmental factors. In this study we investigated the interaction of variations in the G-protein beta 3 subunit (GNB3) and cAMP response element binding protein 1 (CREB1) genes with negative life events in the pathogenesis of MD. One GNB3 polymorphism (rs5443) and four CREB1 polymorphisms (rs2253206, rs2551941, rs6740584, rs11904814) were investigated based on known associations with MD.Methods512 patients with MD and 513 control subjects were genotyped. The frequency and severity of negative life events were measured by the Life Events Scale (LES). Gene-environment interactions (G×E) were assessed using the generalized multifactor dimensionality reduction (GMDR) method.ResultsDifferences in GNB3 rs5443 allele frequencies and genotype distributions were observed between MD patients and controls. Significant G×E interactions were detected between negative life events and genotypic variation of all five single nucleotide polymorphisms (SNPs). Individuals carrying the T- allele of rs5443 (CC), A- allele of rs2253206 (GG), T- allele of rs2551941 (AA), C- allele of rs6740584 (TT) or G- allele of rs11904814 (TT) conferred susceptibility to MD in subjects only exposed to high-negative life events. However, individuals with the T+ allele of rs5443 (CT, TT) were susceptible to MD when exposed to low negative life events.ConclusionsInteractions between GNB3, CREB1 and negative life events were revealed. Further evidence is provided about the role of the environment in genetic vulnerability to MD.

Impact of a Type D Personality on Clinical and Psychometric Properties in a Sample of Turkish Patients With a First Myocardial Infarction.

Recent studies have shown that a Type D personality is associated with an increased risk of cardiac mortality. This study aimed to examine the impact of a Type D personality on clinical and psychometric properties in a sample of Turkish patients with a first myocardial infarction (MI). The study included 131 patients who were admitted to the coronary care unit of a hospital. All of the patients underwent a psychiatric assessment within 2 to 6 months after their MI. Psychiatric interviews were conducted using the Structured Clinical Interview for DSM-IV (SCID-I). Patients also completed the Beck Depression Inventory, the Spielberger State-Trait Anxiety Inventory, the Health Anxiety Inventory, and the Type D personality scale. The patients were divided into 2 groups on the basis of the presence or absence of Type D personality. There was a 38.2% prevalence of Type D personality in the patients with a first MI. Those with this type of personality had a significantly higher frequency of hypertension and stressful life events. The Type D patients also had more psychiatric disorders, including depressive and anxiety disorders, than the non-Type D patients. Our findings suggest that Type D personality traits may increase the risk of hypertension and the risk of psychiatric morbidity in patients with a first MI. We suggest that this type of personality is a contributor to depression and anxiety disorders. These findings emphasize the importance of screening for Type D personality as both a cardiovascular and psychiatric risk marker in patients who have had an MI.

The association between life events and internet addiction among Chinese vocational school students: The mediating role of depression

The purpose of the present study was to test the hypothesis that depression mediated the association between stressful life events and Internet addiction. The participants were randomly recruited from 5 vocational schools in Anhui Province, China and completed a succession of self-completed questionnaires including the Young Internet Addiction Test, the Adolescent Self-rating Life Events Checklist, and the Zung Self-Rating Depression Scale. A structural equation model was applied to examine the mediating role of depression in the association between stressful life events and Internet addiction. The frequency and severity of stressful life events was higher in the Internet addiction group than that in the average Internet use group. Participants in the Internet addiction group experienced more depression when compared to average Internet users. Significant and positive correlations between stressful life events, depression and Internet addiction were detected. The standardized path coefficients from life events to depression and from depression to Internet addiction were significant. The path from life events to internet addiction was also significant. The findings suggested that life events associated with Internet addiction both directly and indirectly, depression mediated the association between life events and Internet addiction.

Stressful life events during pregnancy as risk factors for developing autistic disorder in children

Introduction: This study aimed to examine the role of prenatal stressful events in mothers of children and adolescents with autistic disorder (AD). Methods: This case-control study was conducted in 2014. A total number of 115 children and adolescents with AD were selected by convenience method from the autism rehabilitation centers in Tabriz, Iran. Moreover, 112 typically developing (TD) children and adolescents were selected from public schools using a random clustering method. Two groups were matched in terms of mother's and child's age and mother's educational level. The Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS) semi-structured diagnostic interview was used to evaluate the presence of psychiatric disorders. The diagnosis of AD was made based on the DSM-IV criteria during separate diagnostic interviews by two child and adolescent psychiatrists. The life stressful events’ inventory was used to assess the presence of stressful events during pregnancy. Results: According to Fisher's exact test, the frequency of stressful life events including failure to achieve life goals, high debt, frequent marital conflict, conflict with spouse's family, changes in sleeping habits, and sexual difficulties in the mothers of AD children during pregnancy was significantly higher than the mothers of TD children. Also, mothers of AD children reported significantly higher frequency for the positive stressful life events including the major job progress, starting or finishing education, change of education, location, and summer vacation during pregnancy. Conclusion: Some stressful life events in mothers during pregnancy may be considered as risk factors for developing AD in their children. Further researches are needed to establish the results of this study.

Interaction of estrogen receptor β and negative life events in susceptibility to major depressive disorder in a Chinese Han female population

BackgroundBoth genetic and environmental factors as well as their interaction contribute to the etiology of major depressive disorder (MDD). Estrogen receptor β (ESR2) may play a vital role in the development of MDD in females. The aim of this study is to analyze ESR2 gene polymorphisms and the interaction of ESR2 gene variation and negative life events concerning the risk of developing MDD in females, especially during menopausal stage. MethodsGenotyping was performed by Taqman allelic discrimination assay among 191 female MDD patients and 200 healthy females. Life Events Scale and the generalized multifactor dimensionality reduction method were employed to assess the frequency and severity of negative life events and gene-environment interaction (G×E), respectively. All subjects were regrouped into reproductive and menopausal group based on age. Logistic regression was used to evaluate the set of risk factors. ResultsNo association of ESR2 G×E interaction with MDD was found in the reproductive group. However, in menopausal females, significant G×E interactions between negative life events and allelic variation of rs1256049 and rs4986938 were observed. Individuals with the A+ allele of rs1256049 and rs4986938 were susceptible to MDD when exposed to low negative life events. LimitationAssessment of negative life events was influenced by subjective interpretation. ConclusionsESR2 may modify the interaction between negative life events and MDD in the Chinese Han menopausal females. To our knowledge, this study is the first to report an effect modification between negative life events and ESR2 variations in female MDD patients.

Hookah tobacco use and stressful life events in a sample of young non-daily cigarette smokers

IntroductionUnderstanding factors that influence hookah use among young adults is important given its increasing popularity and health risks. The purpose of this study was to examine whether young adult non-daily cigarette smokers use hookah for stress regulation. We hypothesized that greater perceived stress and greater stressful life events would predict probability and frequency of recent hookah use. MethodsParticipants (n=598, 50.7% male) were non-daily smokers aged 18–24years (M=20.5, SD=1.8), who completed a baseline assessment online or via mobile phone as part of a longitudinal study. Participants had been non-daily smokers for at least six months but had never been daily smokers. ResultsThirty-one percent of participants reported using hookah over the past 14days. Full-time students were more likely to have used hookah recently. More stressful life events and more frequent alcohol use predicted likelihood and frequency of hookah use (ps<0.05). Perceived stress was not associated with hookah use. ConclusionsFindings suggest that hookah tobacco use is related to frequency of stressful life events but not perceived stress among non-daily cigarette smokers. Tobacco prevention and intervention programs should address hookah use and should include adaptive strategies for coping with stressful events.

Prolonged secretion of cortisol as a possible mechanism underlying stress and depressive behaviour.

Stress is associated with the onset of depressive episodes, and cortisol hypersecretion is considered a biological risk factor of depression. However, the possible mechanisms underlying stress, cortisol and depressive behaviours are inconsistent in the literature. This study examined the interrelationships among stress, cortisol and observed depressive behaviours in female rhesus macaques for the first time and explored the possible mechanism underlying stress and depressive behaviour. Female monkeys were video-recorded, and the frequencies of life events and the duration of huddling were analysed to measure stress and depressive behaviour. Hair samples were used to measure chronic cortisol levels, and the interactions between stress and cortisol in the development of depressive behaviour were further evaluated. Significant correlations were found between stress and depressive behaviour measures and between cortisol levels and depressive behaviour. Stress was positively correlated with cortisol levels, and these two factors interacted with each other to predict the monkeys’ depressive behaviours. This finding extends the current understanding of stress/cortisol interactions in depression, especially pertaining to females.

Psychological stress, adverse life events and breast cancer incidence: a cohort investigation in 106,000 women in the United Kingdom.

BackgroundWomen diagnosed with breast cancer frequently attribute their cancer to psychological stress, but scientific evidence is inconclusive. We investigated whether experienced frequency of stress and adverse life events affect subsequent breast cancer risk.MethodsBreast cancer incidence was analysed with respect to stress variables collected at enrolment in a prospective cohort study of 106,000 women in the United Kingdom, with 1783 incident breast cancer cases. Relative risks (RR) were obtained as hazard ratios using Cox proportional hazards models.ResultsThere was no association of breast cancer risk overall with experienced frequency of stress. Risk was reduced for death of a close relative during the 5 years preceding study entry (RR = 0.87, 95 % confidence interval (CI): 0.78–0.97), but not for death of a spouse/partner or close friend, personal illness/injury, or divorce/separation. There was a positive association of divorce with oestrogen-receptor-negative (RR = 1.54, 95 % CI: 1.01–2.34), but not with oestrogen-receptor-positive breast cancer. Risk was raised in women who were under age 20 at the death of their mother (RR = 1.31, 95 % CI: 1.02–1.67), but not of their father, and the effect was attenuated after excluding mothers with breast or ovarian cancer (RR = 1.17, 95 % CI: 0.85–1.61).ConclusionsThis large prospective study did not show consistent evidence for an association of breast cancer risk with perceived stress levels or adverse life events in the preceding 5 years, or loss of parents during childhood and adolescence.Electronic supplementary materialThe online version of this article (doi:10.1186/s13058-016-0733-1) contains supplementary material, which is available to authorized users.

Posttraumatic stress disorder symptoms in youth with vs without chronic pain.

Chronic pain and posttraumatic stress disorder (PTSD) symptoms have been found to co-occur in adults; however, research has not examined this co-occurrence in adolescence, when pediatric chronic pain often first emerges. The aims of this study were to compare the frequency and intensity of PTSD symptoms and stressful life events in cohorts of youth with (n = 95) and without (n = 100) chronic pain and their parents and to determine the association between PTSD symptoms, health-related quality of life, and pain symptoms within the chronic pain sample. All participants completed questionnaire measures through an online survey. Findings revealed that youth with chronic pain and their parents had significantly higher levels of PTSD symptoms as compared with pain-free peers. More youth with chronic pain (32%) and their parents (20%) reported clinically significant elevations in PTSD symptoms than youth without chronic pain (8%) and their parents (1%). Youth with chronic pain also reported a greater number of stressful life events than those without chronic pain, and this was associated with higher PTSD symptoms. Among the chronic pain cohort, higher levels of PTSD symptoms were predictive of worse health-related quality of life and were associated with higher pain intensity, unpleasantness, and interference. Results suggest that elevated PTSD symptoms are common and linked to reduced functioning among youth with chronic pain. Future research is needed to examine PTSD at the diagnostic level and the underlying mechanisms that may explain why this co-occurrence exists.

Sex-related differences in frequency and perception of stressful life events during adolescence

Aim Stressful life events and individual stress experience are important risk factors for the development of physical and mental disorders. One of the modulating factors determining interindividual differences in stress experience is the person’s gender. In the current study, we investigated sex-related differences in the frequency and perception of stressful life events during adolescence, a period characterized by particularly high stress levels.

Personality Strengths as Resilience: A One-Year Multiwave Study.

We examined how personality strengths prospectively predict reactions to negative life events. Participants were 797 community adults from 42 countries. At five points over the course of 1 year, participants completed a series of questionnaires measuring seven personality strengths (hope, grit, meaning in life, curiosity, gratitude, control beliefs, and use of strengths), subjective well-being, and frequency and severity of negative life events. Using hierarchical linear modeling with assessment periods nested within participants, results from lagged analyses found that only hope emerged as a resilience factor. To illustrate the importance of using appropriate lagged analyses in resilience research, we ran nonlagged analyses; these results suggest that all seven personality strengths moderated the effect of negative life events on subjective well-being, with greater strengths associated with healthier outcomes. To provide evidence that personality strengths confer resilience, a prospective examination is needed with the inclusion of events and responses to them. The use of concurrent methodologies and analyses, which is the norm in psychology, often leads to erroneous conclusions. Hope, the ability to generate routes to reach goals and the motivation to use those routes, was shown to be particularly important in promoting resilience.

Parental Threatening Behaviors and Offspring Substance Use: The Moderating Role of Anxiety Sensitivity

ABSTRACTDespite extensive evidence linking childhood exposure to adverse parenting and subsequent substance use, the extant research literature is more limited regarding individual difference factors that may moderate this association. This study examines the moderating role of anxiety sensitivity (AS) in the association between childhood exposure to parental threatening behaviors and substance use in a sample of late adolescents with clinical anxiety. One hundred fifty-one late adolescents with clinical levels of anxiety (18.61 years old; SD = 0.91) completed measures assessing childhood exposure to parental threatening behaviors, AS, alcohol/tobacco and illicit substance use frequency, negative affect, and history of negative life events. A significant moderating effect of AS in the association between childhood exposure to parental threatening behaviors and both average and illicit drug use was found—even after controlling for participants' age and history of negative life events. Specifically, for individuals with high AS, as childhood exposure to parental threatening behaviors increased so too did average and illicit substance use frequency; however, for individuals with low AS, childhood exposure to parental threatening behaviors was not significantly associated with either substance use frequency. Findings underscore the profound impact that early negative experiences have on substance use outcomes, particularly for individuals with high AS who have difficulty coping with and regulating physiological arousal. Limitations and clinical implications of these findings are discussed.

Impact of a type-D personality on clinical and psychometric properties of patients with a first myocardial infarction in a Turkish sample

ObjectiveRecent studies have shown that a Type D personality is associated with an increased risk of cardiac mortality. This study aimed to examine impact of a Type D personality on clinical and psychometric properties of patients with a first myocardial infarction (MI) in a Turkish sample.MethodThe study included 131 patients who were admitted to the coronary care unit of a hospital with a first MI. All the patients underwent a psychiatric assessment within 2–6 months post-MI. Psychiatric interviews were conducted with the Structured Clinical Interview for DSM-IV (SCID-I).ResultsThe first study group (Type D personality) included 50 patients, and the second study group (non-Type D personality) included 81 patients. There was a 38.2% prevalence of the Type D personality in the patients with a first MI. Those with this type of personality had a significantly higher frequency of hypertension and stressful life events. The Type D patients also had more psychiatric disorders, depressive disorders, and anxiety disorders than the non-Type D patients.ConclusionsOur findings suggest that Type D personality traits may increase the risk of hypertension and the risk of psychiatric morbidity in patients with a first MI. Considering that a Type D personality is a stable trait; we suggest that this type of personality is a facilitator of clinical depression and anxiety disorders. These findings emphasize the importance of screening for a Type D personality as a cardiovascular risk marker and a psychiatric risk marker in MI patients.Disclosure of interestThe authors have not supplied their declaration of competing interest.

A183 - Preoperative Psychosocial Factors Associated with Symptom Perception one Year after Bariatric Surgery

Background: A subset of patients experience side effects such as dumping, fatigue and abdominal discomfort after bariatric surgery. The frequency and perceived intensity of such side effects may affect eating behavior and physical activity. Psychological processes may influence the attention, detection, and interpretation of physical symptoms. Anxiety, stress, and negative affect increase the patients selective attention to symptoms, enforce symptom sensitivity and increase symptom reporting. We aimed to study the association between preoperative stressful life events, anxiety, and negative affect with the number and degree of self-perceived side effects one year following bariatric surgery. Method: Questionnaire data from an ongoing prospective study, Oslo Bariatric Surgery Study, was collected from 302 patients preoperatively (79.3% women) and 246 (81.5%) of the participants completed the questionnaire one year after surgery. Mean age was 43.9 years, and 93% underwent Roux-en-Y gastric bypass and 7% gastric sleeve, In response to the question “Have you experienced any side effects/ changes after the operation that affect how you eat or your being physically active?ity” the patients rated the degree of impact, from 0 “No”,to 6 “Very much”, on 11 side effects: change of taste, dumping, pain, feeling full, not wanting to eat, increased hunger, heartburn, vomiting, fatigue, diarrhea, and constipation. Frequency of side effects was calculated as the sum of responses equal or greater than 1. Preoperative independent variables were anxiety and depression (Hospital Anxiety and Depression Scale), self-esteem (Rosenberg s Sself-Eesteem Sscale), and negative thinking about the one s body (The Habit Index of Negative Thinking Body ImageHabitual negative thinking about the body scale). Stressful life events consisteded of? 17 potential stressful negative events, and the respondents indicated degree of impact (1 “low” 4 “high”) and coping (“1 “poor” 3 “ well”).Two single questions measured the extent to which the patients worried that: “..the operation will be unsuccessful“ and “..complications will arise in connection with the operation”.Partial correlations adjusted for percent% weight loss were used. Results: A mean total of 6.8 (SD 2.2) side effects/changes was reported after surgery, with a mean impact of 2.3 (SD 0.6) on their eating behavior or physical activity. Feeling full (95%), dumping (89%) and fatigue (76%) were the side effects/changes most often reported, and affected behavior the most: feeling full (mean 4.3, SD 1.6), dumping (mean 2.9, SD 1.4), fatigue (mean 2.9, SD 1.6). Total degree of impact on behavior from side effects was positively associated with preoperative anxiety (r 1⁄4 0.32), frequency of stressful negative life events (r 1⁄4 0.38), worry about operation success (r 1⁄4 0.22) and complications (r 1⁄4 0.19), and negatively correlated with coping with stress (r 1⁄4 -0.23) and selfesteem (r 1⁄4 -0.20). Preoperative frequency of stressful events and anxiety wereare the factors associated with the most side effects. Diarrhea, dumping, pain, fatigue, not wanting to eat, increased hunger, and heartburn were all associated with preoperative psychological factors. No association was found with change of taste, easily feeling full, vomiting, and constipation. Conclusion: Patients reporting more stressful negative life events and difficulty coping with these events, more anxiety and worry about the treatment prior to surgery, experienced higher selfperceived frequency and impact of side effects on eating behavior and physical activity following surgery. Preoperative anxiety and experience of negative stress may increase the patients’ attention to symptoms, vigilance for detecting potential dangers, and sensitivity for internal body cues after surgery. Self-perceived symptoms are thus important targets for intervention.

Interaction of tryptophan hydroxylase 2 gene and life events in susceptibility to major depression in a Chinese Han population

BackgroundMajor depression (MD) results from a complex synergy between genetic and environmental factors. The aim of this study is to analyze the interaction of tryptophan hydroxylase 2 gene (TPH2) variation and negative life events in the pathogenesis of MD. Three TPH2 polymorphisms, −703G/T (rs4570625), −473T/A (rs11178997), and 1463G/A (rs120074175), were selected based on previous findings of associations with MD. MethodsIn this study, 289 patients with MD and 289 age- and sex-matched control subjects were genotyped. The frequency and severity of negative life events were assessed by the Life Events Scale (LES). Gene-environment interactions (G×E) were assessed using the generalized multifactor dimensionality reduction (GMDR) method. ResultsDifferences in rs11178997 and rs120074175 allele frequencies and genotype distributions were observed between MD patients and controls. Significant G×E interactions between negative life events and allelic variation of rs4570625, rs11178997, and rs120074175 were also observed. Individuals carrying the T− genotype of rs4570625 (GG), T− genotype of rs11178997 (AA), or A− genotype of rs120074175 (GG) were susceptible to MD only when exposed to high-negative life events. However, individuals with the T+ genotypes of rs11178997 (TA, TT) and A+ genotypes of rs120074175 (AG, AA) were susceptible to MD when exposed to low-negative life events. LimitationAssessment of negative life events was influenced by subjective interpretation. ConclusionsInteractions between multiple TPH2 gene alleles and negative life events were revealed by GMDR analysis. Chinese Han individuals with at least one rs11178997 T allele or rs120074175 A allele are susceptible to MD even in the relative absence of high-negative life events.

Interaction between 5-HTTLPR genotype and cognitive stress vulnerability on sleep quality: effects of sub-chronic tryptophan administration.

Background:Abundant evidence suggests that allelic variation in the serotonin transporter-linked polymorphic region (5-HTTLPR) influences susceptibility to stress and its affective consequences due to brain serotonergic vulnerability. Based on recent assumptions, the present study examined whether the 5-HTTLPR genotype may also interact with a vulnerability to chronic stress experience (conceptualized by trait neuroticism) in order to influence sleep quality and, additionally, whether this is influenced by brain serotonergic manipulations.Methods:In a well-balanced experimental design, homozygous S-allele (n = 57) and L-allele (n = 54) genotypes with high and low chronic stress vulnerability (neuroticism) were first assessed for general past sleep quality during a month before onset of the experiment. Then subjects were assessed for sleep quality following 7 days of tryptophan (3.0g/day) or placebo intake.Results:Although high neuroticism was significantly related to a higher frequency of stressful life events and daily hassles, it did not interact with the 5-HTTLPR genotype on general past sleep quality. However, as expected, a 7 day period of tryptophan administration was exclusively associated with better sleep quality scores in the S’/S’ genotype with high trait neuroticism.Conclusions:Current findings suggest that 5-HTTLPR does not directly interact with stress vulnerability in order to influence sleep quality. Instead, based on current and previous findings, it is suggested that the S’/S’ 5-HTTLPR genotype promotes the risk for stress-related sleep disturbances because of an increased susceptibility to the depressogenic consequences of stress. Accordingly, by way of reducing depressive symptomatology, tryptophan augmentation may particularly improve sleep quality in stress-vulnerable individuals carrying the 5-HTTLPR S-allele.

Kindling of life stress in bipolar disorder: comparison of sensitization and autonomy models.

Research on life stress in bipolar disorder largely fails to account for the possibility of a dynamic relationship between psychosocial stress and episode initiation. The kindling hypothesis (Post, 1992) states that over the course of recurrent affective disorders, there is a weakening temporal relationship between major life stress and episode initiation that could reflect either a progressive sensitization or progressive autonomy to life stress. The present study involved a comprehensive and precise examination of the kindling hypothesis in 102 participants with bipolar II disorder that allowed for a direct comparison of sensitization and autonomy models. Polarity-specific tests were conducted across the continuum of event severity with respect to impact and frequency of life events. Hypotheses were polarity- and event-valence specific and were based on the stress sensitization model. Results were only partially consistent with the sensitization model: Individuals with more prior mood episodes had an increased frequency of minor negative events before depression and of minor positive events before hypomania. However, the number of past episodes did not moderate relationships between life events and time until prospective onset of mood episodes. These results are more consistent with a sensitization than an autonomy model, but several predictions of the sensitization model were not supported. Methodological strengths, limitations, and implications are discussed regarding putative changes in stress reactivity that may occur with repeated exposure to mood episodes in bipolar II disorder.

Stressful life events and type 2 diabetes

Objectives:The purpose of this study is to compare cases with type 2 diabetes and their controls for the frequency of stressful life events and social support before the occurrence of the disease.Methods:The study of cases and their controls was undertaken in Belgrade. A case group comprised 179 subjects in whom type 2 diabetes was for the first time diagnosed in the ‘Savski Venac’ Medical Center during the period 2005–2007 year. The diagnosis was made by a specialist of internal medicine according to criteria of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. For each case two controls were chosen among patients with trauma (fracture, reposition, internal/external fixation) who were treated at the ‘Banjica’ Institute for Orthopedic–Surgical Diseases during the same period. Cases and controls were matched by sex, age (±2 years) and place of residence (Belgrade).Data were collected on demographic characteristics, habits, personal history, stressful life events, social support and family medical history.Results:According to multivariate analysis low social support in personal history, such as relatives/friends help and financial assistance in solving problems, and bad management of monthly income were significantly positively related to type 2 diabetes. However, significantly more controls than cases had no financial insurance in case of urgent needConclusion:Examine psychosocial factors play a role in the development of type 2 diabetes.