Effects of vitamin D-related gene polymorphisms on attempted suicide.

OBJECTIVE: Emerging evidence suggests that vitamin D might protect from attempted suicide. The study aimed to investigate the associations between single-nucleotide polymorphisms (SNPs) related to vitamin D levels identified in a large genome-wide association study and attempted suicide in rural China. METHODS: This 1:1 matched case-control study included altogether 510 suicide attempters and 510 community controls. Genotypes of four target SNPs (DHCR7-rs12785878, CYP2R1-rs10741657, GC-rs2282679, and CYP24A1-rs6013897) were determined, and a genetic risk score (GRS) was constructed to evaluate the combined effect of them. Demographic and psychological information was acquired through face-to-face interviews. RESULTS: The A allele of CYP24A1-rs6013897 was significantly associated with attempted suicide (OR = 1.27, 95% CI, 1.03-1.58, P = 0.029), even after adjusting for demographic and psychological confounders (adjusted OR = 1.53, 95% CI, 1.01-2.30, P = 0.043). The GRS analyses revealed a significantly higher risk of attempted suicide with a greater number of low vitamin D alleles (adjusted OR = 1.33, 95% CI, 1.13-1.58, P < 0.001). Subgroup analyses stratified by sex indicated that the genetic associations were only significant among males with adjusted ORs of 3.77 (95% CI, 1.56-9.10) for the A allele of rs6013897 and 2.04 (95% CI, 1.32-3.17) for GRS. CONCLUSIONS: Our findings identity CYP24A1-rs6013897 as a potential biomarker for attempted suicide and indicate that a genetic predisposition to lower vitamin D levels may contribute to attempted suicide. It suggests the possibility that vitamin D may have the preventive potential for attempted suicide.

Negative life events as triggers on suicide attempt in rural China: a case-crossover study.

This study aims to investigate the potential triggering of negative life events (NLEs) on suicide attempt in rural China. A case-crossover design was used to study 1200 suicide attempters aged 15-70 years. NLEs were assessed by a modification of Paykel's Interview for Recent Life Events. NLEs had significant triggering effects on the day of and month of suicide attempt. Marriage/love, family/home, and friend/relationship were the types of NLEs found to trigger suicide attempt when occurring on the day and month of suicide attempt. Specifically, increased risk of suicide attempt was associated with quarreling with a partner or family member on the day and month of suicide attempt. Being disappointed in a love affair, fighting with a partner, family poverty and loss of face during the month of attempts were linked to increase odds of suicide attempt. Further, when month of suicide attempt was assigned as the case period, the impact of NLEs on suicide attempt was greater among those who were younger and without mental disorders. These findings provide knowledge of the triggering of NLEs on suicide attempt, especially among the young and those without mental disorders. Further, family conflicts should be a greater focus of attention in suicide prevention.

Association of polymorphisms in HTR2A, TPH1, and TPH2 genes with attempted suicide in rural China.

OBJECTIVE: We aimed to test the association of polymorphisms in HTR2A, TPH1, and TPH2 genes with attempted suicide in rural China. PARTICIPANTS AND METHODS: On the basis of a case-control study, we recruited 1200 pairs of participants from Shandong Province, China. The blood samples of 712 suicide attempters and 739 nonsuicide attempters were collected finally. We tested seven single nucleotide polymorphisms: rs6313 and rs6311 in HTR2A, rs4537731, rs1800532, and rs1799913 in TPH1, and rs4448731 and rs4641527 in TPH2. RESULTS: In univariate analysis, allele C of rs4537731 was associated negatively with attempted suicide among total and male samples; however, the association was not statistically significant in multivariate analysis after adjusting for other potential confounding factors. No association between other six single nucleotide polymorphisms and attempted suicide was found in the total, male, or female samples. CONCLUSION: This study did not support the effect of these seven serotonergic gene polymorphisms on attempted suicide in rural China.

Functional and dysfunctional impulsivity and attempted suicide in rural China: A paired case-control study.

This study aimed to clarify the relationship between functional and dysfunctional impulsivity and attempted suicide in rural China. Data of this study came from the investigation of 407 suicide attempters and their paired non-suicide attempters matched with the same gender, age (±3 years) and residence area in six counties in rural Shandong, China. Suicide attempters accounted for a lower proportion on high functional impulsivity, but a higher proportion on high dysfunctional impulsivity than non-suicide attempters. Dysfunctional impulsivity in the male denoted a significant risk factor for attempted suicide, even after adjustment for psychiatric disorder and demographic factors. Suicide attempters with high dysfunctional impulsivity had a higher percent of family suicide history than those with low dysfunctional impulsivity. High functional impulsivity was a significant protective factor for attempted suicide in the group aged 35-59 years, but a significant risk factor in the group aged 15-34 years. Suicide attempters with low functional impulsivity had poorer economic status and older age than those with high functional impulsivity. Our findings support the key roles of functional and dysfunctional impulsivity in attempted suicide among rural residents of China.

The COMT rs4680 polymorphism and suicide attempt in rural Shandong, China.

BACKGROUND: Suicide attempt is a major public health problem and are associated with genetic factors. This paired case-control study examined the association between the COMT gene rs4680 polymorphism and suicide attempts. METHODS: A case-control study of 369 (117 men, 31.7%; mean age=44.1±13.3 years) suicide attempters and an equal number of controls without a lifetime history of suicide attempt matched on sex, age, and residence was carried out in rural Shandong, Eastern China. Demographics and psychiatric history were obtained through face-to-face interviews. Blood samples were collected during interviews and the COMT gene rs4680 polymorphism was analyzed using the ligation detection reaction method. RESULTS: The G/G genotype was significantly more prevalent in female suicide attempters than their matched controls. Conditional logistic regression showed that the G/G genotype was significantly associated with an increased risk of suicide attempts only for women (odds ratio=2.3; 95% confidence interval: 1.2-4.2). CONCLUSION: The findings support an association between the COMT gene rs4680 polymorphism and suicide attempts only in women. Further research with larger samples is needed to explore the interactions of the COMT gene rs4680 polymorphism and sex and psychiatric disorders on suicide attempts.

Beck Hopelessness Scale: Psychometric Properties Among Rural Chinese Suicide Attempters and Non-Attempters.

The authors recruited 401 suicide attempters from general hospitals and 409 matched non-attempters to evaluate the psychometric properties of the Beck Hopelessness Scale (BHS) in rural China. All participants completed the BHS, Center for Epidemiologic Studies Depression Scale (CES-D), and Trait Anxiety Inventory (TAI). Suicide attempters had higher BHS scores than non-attempters. Cronbach's alpha coefficients were satisfactory and BHS scores significantly correlated to CES-D and TAI scores. Confirmatory factor analysis supported a four-factor model for suicide attempters and a five-factor model for non-attempters. The BHS is satisfactory in assessing hopelessness among suicide attempters in rural China.

[A case-control study on the quality of life and the way of response among patients with anxiety disorder in Shandong province].

OBJECTIVE: To explore the characteristics related to the quality of life and the way of response among patients with anxiety disorder in Shandong province. METHODS: Case-control study was adopted, with secondary data analysis on mental disorders among adults over 18 years of age, in Shandong province. 720 patients with anxiety disorder who met the anxiety diagnostic criteria of DSM-IV, were selected from the database, according to the distributions on gender, age (±3 years of age), village or community. 720 persons without any psychiatric diagnosis were selected and served as controls, under 1 :1 paired choice. Research tools would include:General Health Questionnaire (GHQ-12),Quality of Life Questionnaire (QLQ), Simplified Coping Style Questionnaire (SCSQ), and questionnaire on general information. RESULTS: Scores of QLQ among patients with anxiety disorder were lower than that of the control group, with statistically significant difference(P < 0.01). Scores on the negative ways of coping among patients with anxiety disorder were higher than the scores of the control group, with statistically significant difference(P < 0.01). Regardless of gender, age, occupation, education, marriage, religious belief etc., results from the 'two factors anova-analysis' showed that the scores of QLQ among patients with anxiety disorder were still lower than the scores of the control group while the scores on negative coping were still higher than the scores of the control group. CONCLUSION: Patients with anxiety disorder and having poor quality of life outnumbered the ones from the control group, and using negative coping ways to cope with the stress events.

Nutrient uptake of rice roots in response to infestation of Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

This study investigated the uptake of three macronutrients, including nitrogen (N), phosphorus (P), and potassium (K), by rice roots in response to different infestation levels of Nilaparvata lugens (Stål) (Homoptera: Delphacidae). Hydroponics experiments were conducted on the rice variety 'Zhendao 2' (moderately resistant to Tryporyza incertulas, Lepidoptera: Pyralidae) and the variety 'Xiushui 63' (susceptible to N. lugens). In 'Zhendao 2', N. lugens infestation significantly influenced the uptake of P and K but not N, with P and K uptake decreasing as the duration of N. lugens infestation increased. In 'Xiushui 63', N. lugens infestation influenced N, P, and K uptake to a different degree, depending on the infestation level, in which infestation for 2, 4, 6, and 8 d at a density of 60 nymphs did not affect N uptake, but such infestation levels significantly influenced the uptake of P and K. After the removal of N. lugens from rice plants, the N uptake recovered from infestation faster than that for P and K in the variety 'Zhendao 2', whereas the recovery rate of K uptake was faster than that for N and P in the variety 'Xiushui 63'. The recovery rate of the nutrient uptake was negatively correlated to the density and duration of infestation. The experimental results demonstrated that N, P, and K uptake of rice roots were largely not influenced by N. lugens infestation when the pest density was controlled below 15 nymphs per hill. This infestation level was in agreement with the proposed economic thresholds for control measures against the N. lugens infestation on rice plants.