Mania,Hypomania, and Suicidality: Findings from a Prospective Community Study

ABSTRACT

We examined prospectively whether mania and hypomania are associated with an elevated risk for suicidality in a community sample of adolescents and young adults. Baseline and four-year follow-up data were used from the Early-Developmental-Stages-of-Psychopathology (EDSP) Study, a prospective longitudinal study of adolescents and young adults in Munich. Suicidal tendencies (ideation/attempts), mania, and hypomania were assessed using the standardized Munich-Composite-International-Diagnostic-Interview. At baseline, mania/hypomania was associated to a different degree with suicidality (Odds ratios [OR] range from 1.9 to 13.7). In the prospective analyses, the risk for subsequent incident suicidal ideation was increased in the presence of prior mania (38.0% vs. 14.1%; OR = 4.4; 95% CI = 1.4–13.5). No associations could be found between prior mania/hypo-mania and incident suicide attempts. The prospective analyses revealed a remarkable relationship between preexisting mania and increased risk for subsequent suicidal ideation.     

Social inequalities in depression and suicidal ideation among older primary care patients

Purpose

Depression and suicide are major public health concerns, and are often unrecognized among the elderly. This study investigated social inequalities in depressive symptoms and suicidal ideation among older adults.

Methods

Data come from 1,226 participants in PROSPECT (Prevention of Suicide in Primary Care Elderly: Collaborative Trial), a large primary care-based intervention trial for late-life depression. Linear and logistic regressions were used to analyze depressive symptoms and suicidal ideation over the 2-year follow-up period.

Results

Mean Hamilton Depression Rating Scale (HDRS) scores were significantly higher among participants in financial strain [regression coefficient (b) = 1.78, 95 % confidence interval (CI) = 0.67–2.89] and with annual incomes below $20,000 (b = 1.67, CI = 0.34–3.00). Financial strain was also associated with a higher risk of suicidal ideation (odds ratio = 2.35, CI = 1.38–3.98).

Conclusions

There exist marked social inequalities in depressive symptoms and suicidal ideation among older adults attending primary care practices, the setting in which depression is most commonly treated. Our results justify continued efforts to understand the mechanisms generating such inequalities and to recognize and provide effective treatments for depression among high-risk populations.     

The risk of adolescent suicide across patterns of drug use: a nationally representative study of high school students in the United States from 1999 to 2009

Objective

Substance use is associated with suicidal ideation, planning and attempts among adolescents, but it is unclear how this association varies across different types and number of substances. This study examined the association between patterns of substance use and suicidality among a nationally representative sample of high school students in the United States during the last decade.

Method

Data from the 2001 to 2009 Youth Risk Behavior Survey including 73,183 high school students were analyzed. Logistic regression analyses examined the association between lifetime use of ten common substances of abuse (alcohol, cocaine, ecstasy, hallucinogens, heroin, inhalants, marijuana, methamphetamines, steroids, and tobacco) and four measures of suicidality over the last year (suicidal ideation, suicide plan, suicide attempt, and severe suicide attempt requiring medical attention), controlling for potential confounders (socio-demographic variables, interpersonal violence, sexual intercourse, and symptoms of depression and eating disorder).

Results

Among the ten substances, univariate analysis demonstrates that adolescents reporting a history of heroin use have the strongest association with suicidal ideation, suicide plan, suicide attempts and severe suicide attempts in the last year (odds ratio = 5.0, 5.9, 12.0, and 23.6 compared to non-users), followed by users of methamphetamines (OR = 4.3–13.1) and steroids (OR = 3.7–11.8). Cocaine, ecstasy, hallucinogens and inhalants had a moderate association with suicidality (OR = 3.1–10.8). Users of marijuana, alcohol and tobacco also had an increased odds ratio of suicidality (OR = 1.9–5.2). The association between each of ten substances and the four measures of suicidality remained significant with multivariate analysis controlling for multiple confounders (p < 0.05), except for the association between alcohol use and severe suicide attempts. The seven illicit substances had a stronger association with severe suicide attempts as compared to all other confounding risk factors except depression. The number of substances used had a graded relationship to suicidality.

Conclusions

Substance abuse is a strong risk factor for suicidal thoughts and behaviors among American high school students, with the strength of this relationship dramatically increasing with particular illicit drugs and a higher number of substances. The findings reinforce the importance of routine screening for substance abuse in the assessment of adolescent suicide risk.     

Agency is Associated with Decreased Emotional Distress and Suicidal Ideation in Military Personnel

Suicides in the U.S. military continue to rise at a rapid rate. Identification of protective factors that reduce risk for suicidal thoughts and behaviors among military personnel are therefore needed. Agency—the sense that one is competent, effective, and in control of one's life—has shown to reduce the effects of hopelessness and emotional distress on suicidal thoughts and attempts in non-military populations. The current study explores the association of agency with suicidal ideation in a sample (n = 273) of active duty Air Force Security Forces personnel. Results of generalized regression modeling suggest that agency is directly associated with decreased emotional distress and severity of suicidal ideation, but does not moderate the effect of emotional distress on suicidal ideation.     

Prevalence and Associated Factors of Depression Among Post-Stroke Patients in Bangladesh

To assess the prevalence of depression and its associated factors among patients with stroke in Bangladesh. We conducted a cross-sectional study among 164 post-stroke patients attending two hospitals in Dhaka city between January and June 2011. Depression was measured using the Hamilton Depression Rating Scale. Factors associated with depression were analyzed using multivariate logistic regression. Results: The prevalence of depression was 70 and 32 % had severe depression. The mean ± sd age of the participants was 58.91 ± 7.03 years. Multivariate regression analysis revealed that factors significantly associated with depression were living in a joint family (OR = 13.5, 95 % CI = 1.3–145.7, p = 0.032), those unable to perform daily activities by themselves (OR = 14.9, 95 % CI = 2.0–108.1, p = 0.008) and those with comorbid dysphasia (OR = 9.5, 95 % CI = 1.0–86.9, p = 0.046) and hypertension (OR = 5.2, 95 % CI = 2.3–15.4, p = 0.012). Depression is a significant health problem among post-stroke patients in Bangladesh. This leads to careful management of depression for social support to achieve better patient outcome.     

Identification of Suicide Risk Factors in Medellín,Colombia: A Case-Control Study of Psychological Autopsy in a Developing Country

The incidence, methods and risk factors for suicide may vary among the different cultures, which makes necessary to study the risk factors for suicide in specific settings in order to design adequate intervention strategies. This study aims to determine the risk factors for suicide in Medellín (Colombia). It is a case-control study conducted among 108 individuals who committed suicide and 108 deceased in accidents, matched for age and gender. Both cases and controls were examined by means of psychological autopsy. Conditional logistic regression analysis identified the following factors: Adverse life events in the last six months (OR = 11.81, 95% CI: 4.29–32.52), family history of suicide (OR = 10.82, 95% CI: 2.23–52.47), major depressive episode (OR = 4.58, 95% CI: 1.53–13.67) and expression of a wish to die (OR = 3.54, 95% CI: 1.25–10.06). These findings may suggest that risk factors for suicide are similar across cultures.     

Suicidal Ideation Among Korean Elderly: Risk Factors and Population Attributable Fractions

Objectives: The objective of this study was to investigate the risk factors of suicidal ideation and their population attributable fraction (PAF) in a representative sample of the elderly population in Korea. Method: We examined the data set from the Survey of Living Conditions and Welfare Needs of Korean Older Persons, which was conducted by the Korea Institute for Health and Social Affairs (KIHASA) in 2011. In that survey, 10,674 participants were randomly selected from those older than age 65. Simultaneous multivariate logistic regression was used to investigate the risk factors of suicidal ideation in terms of their sociodemographic and health-related variables. Subsequently, the PAF was calculated with adjustment for other risk factors. Results: The weighted prevalences of depression and suicidal ideation were 30.3% and 11.2%, respectively. In multivariate analysis, factors significantly associated with decreased risk of suicidal ideation included old-old age (odds ratio [OR] = 0.66 for 75 to 79 years, OR = 0.52 for 80 to 84 years, OR = 0.32 for older than 85 years), economic status (OR = 0.59 for 5th quintile; more than US$25,700 per year), whereas those associated with increased risk included poor social support (OR = 1.28), currently smoking (OR = 1.42), sleep problems (OR = 1.74), chronic illness (OR = 1.40), poor subjective health (OR = 1.56), functional impairment (OR = 1.45), and depression (OR = 4.36). Depression was associated with a fully adjusted PAF of 45.7%, followed by chronic illness (19.4%), poor subjective health status (18.9%), sleep problems (14.1%), functional impairment (4.9%), poor social support (4.2%), and currently smoking (3.6%). Conclusions: Preventive strategies focused particularly on depression might reduce the impact of suicidal ideation in the elderly population. Also, specific mental health centers focused on the specific needs of the elderly population should be established to manage suicidal risk.     

Association between interleukin-1α C(−889)T polymorphism and Alzheimer’s disease: a meta-analysis including 12,817 subjects

Epidemiological studies have evaluated the association between interleukin-1 (IL-1)α C(?889)T polymorphism and Alzheimer’s disease (AD), but the results remain inconclusive. This meta-analysis was, therefore, designed to clarify these controversies. Systematic searches of electronic databases Embase, PubMed, and Web of Science as well as hand searching of the references of identified articles and the meeting abstracts were performed. Statistical analyses were performed using software Review Manager (Version 5.1.2) and Stata (Version 11.0). The pooled odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were calculated. A total of 28 publications including 29 studies were involved. There was a significant association between IL-1α C(?889)T polymorphism and AD (for T allele vs. C allele: OR = 1.14, 95 % CI = 1.07–1.21; for T/T vs. C/C: OR = 1.39, 95 % CI = 1.18–1.63; for dominant model: OR = 1.13, 95 % CI = 1.04–1.22; and for recessive model: OR = 1.39, 95 % CI = 1.20–1.60). Significant association was found for Asians, Caucasians, and early-onset Alzheimer’s disease (EOAD) but for late-onset Alzheimer’s disease (LOAD). This meta-analysis indicates that there is a significant association between IL-1α C(?889)T polymorphism and AD as well as EOAD.     

Functional neuroimaging in migraine

Migraine can be accompanied by some gastrointestinal (GI) disorders. In this study, we aimed to investigate the relationship between migraine and tension-type headache (TTH) and different lower and upper GI disorders as well as non-alcoholic fatty liver (NAFLD) and cholelithiasis. This cross-sectional study included 1574 overweight and obese participants who were referred to the Obesity Research Center of Sina Hospital, Tehran, Iran. The diagnosis of migraine and TTH was made by an expert neurologist based on the international classification of headache disorders-III β (ICHD III β). GI disorders, including irritable bowel syndrome (IBS), constipation, heartburn, dyspepsia, non-alcoholic fatty liver (NAFLD), and cholelithiasis, were diagnosed by a gastroenterology specialist. The overall mean age of participants was 37.44 ± 12.62. A total of 181 (11.5%) migraine sufferers (with and without aura) and 78 (5%) TTH subjects were diagnosed. After adjusting for potential confounders by multivariable regression models, migraine had significant association with IBS (OR = 5.16, 95% CI = 2.07–12.85, P = 0.000), constipation (OR = 3.96, 95% CI = 2.25–6.99, P = 0.000), dyspepsia (OR = 4.12, 95% CI = 2.63–6.45, P = 0.000), and heartburn (OR = 5.03, 95% CI 2.45–10.33, P = 0.000), while the association between migraine and NAFLD was marginally significant (OR = 2.03, 95% CI = 0.98–4.21, P = 0.055). Furthermore, the prevalence of NAFLD (OR = 2.93, 95% CI 1.29–6.65, P = 0.010) and dyspepsia (OR = 4.06, 95% CI = 2.24–7.34, P = 0.000) was significantly higher in TTH patients than the headache-free group. These findings show an association between GI disorders and primary headaches especially migraine and are, therefore, of value to the management of migraine and TTH. Further studies should investigate the etiology of the relationship between all subtypes of primary headaches and GI disorders.     

Familial Liability to Epilepsy and Attention-Deficit/Hyperactivity Disorder: A Nationwide Cohort Study

Background

Epilepsy and attention-deficit/hyperactivity disorder (ADHD) are strongly associated; however, the underlying factors contributing to their co-occurrence remain unclear. A shared genetic liability has been proposed as one possible mechanism. Therefore, our goal in this study was to investigate the familial coaggregation of epilepsy and ADHD and to estimate the contribution of genetic and environmental risk factors to their co-occurrence.

Social support and suicidal ideation in Japan: are home visits by commissioned welfare volunteers associated with a lower risk of suicidal ideation among elderly people in the community?

Aims

Social support has consistently been reported to be effective in reducing suicidal ideation. This cross-sectional study was performed to determine whether home visits by commissioned welfare volunteers (i.e., organizations of community residents appointed by national or prefectural governments) are associated with a lower risk of suicidal ideation among the elderly.

Methods

In August 2010, questionnaires were sent to all residents aged ≥65 years in three municipalities (n = 21,232) in Okayama prefecture, Japan, and 13,929 returned the questionnaire (response rate: 65.6 %). We finally analyzed 11,218 subjects. Both home visits by commissioned welfare volunteers and suicidal ideation within the last 30 days were assessed in the questionnaire. Odds ratios (ORs) and 95 % confidence intervals (CIs) for suicidal ideation were calculated adjusting for age, sex, educational attainment, and marital status. We then additionally adjusted for instrumental and emotional support, separately.

Results

The prevalence of suicidal ideation was 10.0 % and higher in women than in men (11.4 % vs. 8.0 %). Home visits were significantly associated with a lower risk of suicidal ideation after adjusting for instrumental and emotional support, respectively (OR: 0.60, 95 % CI: 0.53–0.69; OR: 0.67, 95 % CI: 0.59–0.78). In sex-stratified analysis, the association was clearer for women than for men: the corresponding ORs among women were 0.55 (95 % CI: 0.46–0.65) and 0.61 (95 % CI: 0.52–0.73), whereas they were 0.71 (95 % CI: 0.56–0.90) and 0.78 (95 % CI: 0.61–0.99) among men.

Conclusion

Our findings suggest that home visits by commissioned welfare volunteers are significantly associated with lower suicidal ideation among the elderly, particularly in women.     

Prevalence and risk factors of psychotic symptoms: in the city of Izmir, Turkey

Background

Psychotic symptoms, psychotic-like experiences and schizotypal signs can emerge in different socio-cultural circumstances and cause clinical or non-clinical pictures. Transient or self-limiting psychotic-like experiences are more prevalent than clinical psychotic disorders. The aim of this study is to determine the prevalence and sociodemographic correlates of psychotic symptoms in an urban area.

Methods

A cross-sectional study was conducted among the residents of two districts in the urban area of Izmir, Turkey. Among the systematically selected 1,500 residents of 85,212-study population, a total of 1,268 individuals (response rate: 84.5%) were screened for any lifetime psychotic symptoms.

Results

Composite International Diagnostic Interview (CIDI) was used to assess psychotic symptoms. CIDI (+) psychotic symptoms were found in 3.6% of the screened sample. Logistic regression analysis showed that being a female (OR = 2.4, 95% CI = 1.2–5.1), having a first degree family history of any mental disorders (OR = 13.9, 95% CI = 5.7–34.3), lack of social support (OR = 4.5, 95% CI = 2.3–8.6) and alcohol use (OR = 4.9, 95% CI = 2.3–10.6) were all related to psychotic symptoms.

Conclusion

Prevalence of any psychotic symptom is lower compared to European studies. Alcohol might be considered as a risk factor for developing psychotic symptoms in the Turkish cultural setting.     

Obstetrical epidural and spinal anesthesia in multiple sclerosis

To examine obstetrical epidural and spinal anesthesia use in women with multiple sclerosis (MS) and the relationship with MS clinical factors. This was a retrospective cohort study, linking clinical data from women with MS in the British Columbia (BC) MS database to obstetrical data (1998–2009) from the BC Perinatal Database Registry. We compared epidural use in 431 deliveries to women with MS and 2,959 deliveries from the general population, as well as spinal use in cesarean deliveries (128 to women with MS and 846 in the general population), considering parity and using multivariate models. We also examined the association between epidural or spinal anesthesia and MS clinical factors—disease duration and disability [Expanded Disability Status Scale (EDSS) score]. Of 431 deliveries to women with MS, 116 were exposed to epidural anesthesia and of 128 cesarean deliveries, 82 were exposed to spinal anesthesia. The use of epidural anesthesia was similar in nullipara (adjusted OR = 0.86, 95 % CI = 0.63–1.18, p = 0.36), but more likely in multipara with MS (adjusted OR = 1.75, 95 % CI = 1.20–2.54, p = 0.004). Spinal anesthesia use in cesarean deliveries was comparable between the MS and general population cohorts (adjusted OR = 0.84, 95 % CI = 0.55–1.31, p = 0.45). Women who delivered 5 to <10 years after MS onset were less likely to have an epidural (adjusted OR = 0.57, 95 % CI = 0.34–0.95, p = 0.03) vs. those delivering within 5 years. EDSS was not associated with use of either type of anesthesia (adjusted p > 0.1). Contrary to previous studies, epidural anesthesia use differed between women with MS and the general population and was influenced by parity and MS disease duration; these findings warrant further investigation.     

Rates and risk factors for suicidal ideation,suicide attempts and suicide deaths in persons with HIV: a systematic review and meta-analysis

BackgroundPeople living with HIV/AIDS (PLWHA) must contend with a significant burden of disease. However, current studies of this demographic have yielded wide variations in the incidence of suicidality (defined as suicidal ideation, suicide attempt and suicide deaths).AimsThis systematic review and meta-analysis aimed to assess the lifetime incidence and prevalence of suicidality in PLWHA.MethodsPublications were identified from PubMed (MEDLINE), SCOPUS, OVID (MEDLINE), Joanna Briggs Institute EBP and Cochrane Library databases (from inception to before 1 February 2020). The search strategy included a combination of Medical Subject Headings associated with suicide and HIV. Researchers independently screened records, extracted outcome measures and assessed study quality. Data were pooled using a random-effects model. Subgroup and meta-regression analyses were conducted to explore the associated risk factors and to identify the sources of heterogeneity. Main outcomes were lifetime incidence of suicide completion and lifetime incidence and prevalence of suicidal ideation and suicide attempt.ResultsA total of 185 199 PLWHA were identified from 40 studies (12 cohorts, 27 cross-sectional and 1 nested case-control). The overall incidence of suicide completion in PLWHA was 10.2/1000 persons (95%CI: 4.5 to 23.1), translating to 100-fold higher suicide deaths than the global general population rate of 0.11/1000 persons. The lifetime prevalence of suicide attempts was 158.3/1000 persons (95%CI: 106.9 to 228.2) and of suicidal ideation was 228.3/1000 persons (95%CI: 150.8 to 330.1). Meta-regression revealed that for every 10-percentage point increase in the proportion of people living with HIV with advanced disease (AIDS), the risk of suicide completion increased by 34 per 1000 persons. The quality of evidence by Grading of Recommendations, Assessment, Development and Evaluations for the suicide deaths was graded as ‘moderate’ quality.ConclusionsThe risk of suicide death is 100-fold higher in people living with HIV than in the general population. Lifetime incidence of suicidal ideation and attempts are substantially high. Suicide risk assessments should be a priority in PLWHA, especially for those with more advanced disease.     

Parental Mental Disorders and Suicidal Behavior in the Nigerian Survey of Mental Health and Well-Being

The objective of this study was to determine which parental mental disorders predict offspring suicidal behavior in a general adult population sample of a sub-Saharan African country. The World Health Organization Composite International Diagnostic Interview, version 3 was used to assess respondents' suicidal behaviors as well as psychopathology in their parents. The effects of parental disorders in predicting offspring suicide ideation and attempts were examined in a series of bivariate and multivariate models. Sections on suicidality were administered to the entire sample (n = 6752), but associations with parental psychopathology were examined in a subsample of respondents (n = 2143). Lifetime prevalence (95% confidence interval) of suicide ideation, plans, and attempts was 3.2% (1.4–6.5), 1.0% (0.4–7.5), and 0.7% (0.5–1.0) respectively. Parental panic disorder and substance abuse were associated with suicide ideation in offspring, but only parental panic disorder was linked to suicide attempts. Parental panic disorder predicted the onset and persistence of suicide ideation and attempts and also which persons with suicide ideation go on to make a suicide attempt. This study further affirms findings from previous studies of the role of disorders characterized by anxiety and impulse control in suicide attempts and as being a probable link in the transmission of suicidal behavior to offspring.     

Postcards in Persia: A Twelve to Twenty-four Month Follow-up of a Randomized Controlled Trial for Hospital-Treated Deliberate Self-Poisoning

This study reports the outcomes, during follow-up, of a low-cost postcard intervention in a Randomized Control Trial of hospital-treated self-poisoning (n = 2300). The intervention was 9 postcards over 12 months (plus usual treatment) versus usual treatment. Three binary endpoints at 12–24 months (n = 2001) were: any suicidal ideation, suicide attempt, or self-cutting. There was a significant reduction in any suicidal ideation (RRR 0.20 CI 95% 0.13–0.27), (NNT 8, 6–13), and any suicide attempt (RRR 0.31, 0.06–0.50), (NNT 35, 19–195), in this non-western population. However, there was no effect on self-cutting (RRR -0.01, -1.05–0.51). Sustained, brief contact by mail may reduce some forms of suicidal behavior in self-poisoning patients during the post intervention phase.     

Rumination and Pessimistic Certainty as Mediators of the Relation Between Lifetime Suicide Attempt History and Future Suicidal Ideation

This study examined whether rumination and certainty about pessimistic future-event predictions (P-Certainty) would mediate the relation between lifetime suicide attempt history and future suicidal ideation. Young adults, ages 18–25 (N = 143), with a suicide attempt history (n = 32) or no previous suicide attempt history (n = 111) at baseline, were followed up 2–3 years later and completed measures of rumination, depressive symptoms, hopelessness, suicidal ideation, and pessimistic future-event certainty. Lifetime suicide attempts at baseline were associated with higher suicidal ideation at follow up, and this relation was mediated by rumination and P-Certainty. Suicide attempters may be vulnerable to later ideation due to higher levels of rumination and also certainty in their pessimistic future expectations.     

Racial and ethnic disparities in the use of antipsychotic medication: a systematic review and meta-analysis

Objective

To conduct a systematic review and meta-analysis of published evidence on ethnic or racial disparities in the outpatient use versus non-use of antipsychotics and in the outpatient use of newer versus older antipsychotics.

Method

Electronic databases were searched for potentially relevant studies. Two independent reviewers conducted the review in three stages: title review, abstract review and full-text review. Included studies were those that: (a) report measures of disparity in the outpatient use of antipsychotic drugs in clearly defined racial or ethnic groups (b) have a primary focus on ethnic or racial disparities, and (c) have adjusted for factors known to influence medicine use. Odds ratios were pooled following the inverse-variance method of weighting effect sizes. I ² statistics were calculated to quantify the amount of variation that is likely due to heterogeneity between studies. Funnel plots were produced and Egger’s statistic was calculated to assess potential publication bias.

Results

No significant differences were found in the odds of using any antipsychotics among African Americans (OR = 1.01, CI = 0.99–1.02) compared with non-African Americans and among Latinos (OR = 0.98, CI = 0.86–1.13) compared with non-Latinos. Small to moderate but statistically non-significant disparities were also noted in other ethnic groups: Asians (OR = 1.10, CI = 0.88–1.36), Maoris (OR = 0.78, CI = 0.53–1.13) and Pacific Islanders (OR = 0.97, CI = 0.84–1.11). Among those who received antipsychotic medication, African Americans (OR = 0.62, CI = 0.50–0.78) and Latinos (OR = 0.77, CI = 0.73–0.81) appeared to have lower odds of receiving newer antipsychotics compared with non-African Americans and non-Latinos.

Conclusion

No significant ethnic disparities in the use versus non-use of any antipsychotics were observed, but, among those who received antipsychotic treatment, ethnic minorities were consistently less likely than non-ethnic minorities to be treated with newer antipsychotics.     

The association between the LRRK2 G2385R variant and the risk of Parkinson’s disease: a meta-analysis based on 23 case–control studies

Clinical diagnosis of Parkinson’s disease (PD) is essential but misdiagnosis of PD-like diseases is quite common. LRRK2 G2385R variants have been extensively examined for the association to the risk of Parkinson’s disease. However, results from different studies are inconsistent. The purpose of this meta-analysis was to assess the association between the LRRK2 G2385R variants and the risk of PD. A systematic literature search was performed for 6 databases up to January of 2014 to identify case–control studies involving LRRK2 G2385R variants and the risk of PD. A total of 12,915 cases and 12,451 controls in 23 case–control studies were included in this meta-analysis. The results indicated that the variant A allele carriers (GA + AA) increased risk of PD when compared with the homozygote GG (GA + AA vs. GG: OR = 2.4, 95 % CI = 1.97 to 2.92, P < 0.00001). In the subgroup analysis by ethnicity, increased risks were identified among Chinese (OR = 2.69, 95 % CI = 2.1–3.45, P < 0.00001) as well as in non-Chinese (OR = 2.17, 95 % CI 1.75–2.69, P < 0.00001). In the subgroup analysis by age of onset, significant associations were found in both later-onset PD (LOPD) and early-onset PD (EOPD) cases. And there was no significant difference of the allele frequency between patients with LOPD and EOPD (OR = 1.18, 95 % CI = 0.77–1.80, P = 0.45). Our results suggest that the LRRK2 G2385R variants contribute to the susceptibility of PD especially in Chinese PD. Meanwhile, it is possible that age is not the risk factor to facilitate G2385R gene mutation.     

COMT Val158Met and PPARγ Pro12Ala polymorphisms and susceptibility to Alzheimer’s disease: a meta-analysis

The aim of this study was to explore whether the catechol-O-methyltransferase (COMT) Val158Met or the peroxisome proliferator-activated receptor-gamma (PPARγ) Pro12Ala polymorphisms are associated with susceptibility to Alzheimer’s disease (AD). We conducted a meta-analysis of the associations between the COMT Val158Met and the PPARγ Pro12Ala polymorphisms and AD in subjects. Meta-analysis showed no association between AD and the COMT G allele in any of the study subjects [odds ratio (OR) = 0.972, 95 % confidence intervals (95 % CI) = 0.893–1.059, p = 0.515]. Stratification by ethnicity indicated an association between the COMT GG+GA genotype and AD in an Asian group (OR = 0.702, 95 % CI = 0.517–0.953, p = 0.023), but not in Europeans (OR = 1.058, 95 % CI = 0.868–1.289, p = 0.579). Homozygote contrast analysis showed the same pattern for the COMT GG+GA genotype. Meta-analysis showed no association between AD and the PPARγ polymorphism (OR for the C allele = 0.963, 95 % CI = 0.818–1.134, p = 0.649). This meta-analysis identified an association between AD and the COMT Val158Met polymorphism in Asians but not in Europeans, but it revealed no association between AD and the PPARγ Pro12Ala polymorphism.