Major depressive disorder (MDD) is a phenotypically heterogeneous disorder with a complex genetic architecture. In this study, genomic-relatedness-matrix restricted maximum-likelihood analysis ...(GREML) was used to investigate the extent to which variance in depression symptoms/symptom dimensions can be explained by variation in common single nucleotide polymorphisms (SNPs) in a sample of individuals with MDD (N = 1,558) who participated in the National Institute of Mental Health Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. A principal components analysis of items from the Hamilton Rating Scale for Depression (HRSD) obtained prior to treatment revealed 4 depression symptom components: (a) appetite, (b) core depression symptoms (e.g., depressed mood, anhedonia), (c) insomnia, and (d) anxiety. These symptom dimensions were associated with SNP-based heritability (hSNP2) estimates of 30%, 14%, 30%, and 5%, respectively. Results indicated that the genetic contribution of common SNPs to depression symptom dimensions were not uniform. Appetite and insomnia symptoms in MDD had a relatively strong genetic contribution whereas the genetic contribution was relatively small for core depression and anxiety symptoms. While in need of replication, these results suggest that future gene discovery efforts may strongly benefit from parsing depression into its constituent parts.
General Scientific Summary
The genetic underpinnings of MDD remain enigmatic despite significant research efforts. This study suggests that depression symptom dimensions might have different heritability estimates, and that future genetic research might benefit from parsing depression into its constituent parts.
The Dietary Guidelines for Americans recommend a 20–35 percent daily intake of fat. Resisting the temptation to eat high-fat foods, in conjunction with stage of readiness to avoid these foods, has ...been shown to influence healthy behavior change. Data (N = 6516) from three randomized controlled trials were pooled to examine the relationships among direct intervention effects on temptations and stage of change for limiting high-fat foods. Findings demonstrate separate simultaneous growth processes in which baseline level of temptations, but not the rate of change in temptations, was significantly related to the change in readiness to avoid high-fat foods.
Sexual and gender minority youth (SGMY) are at greater risk than their heterosexual and cisgender counterparts for suicidal thoughts and behaviors (STB) and non-suicidal self-injury (NSSI). Unique ...stressors (i.e., minority stressors) specific to SGMY’s stigmatized identities such as discrimination or concealment of one’s identity are posited to explain these disparities. However, there is limited research examining the associations among minority stressors, affective mediating processes, and STB and NSSI in sexual and gender minority youth’s daily lives. We conducted a 28-day daily diary study to test the mediating effects of daily negative and positive affect and emotion dysregulation between minority stressors and STB and NSSI among SGMY who were recruited from clinical and community settings. Participants were 92 SGMY, ages 12 to 19 years old (
M
= 16.45;
SD
= 1.81; 64% cisgender; 69% White). Results indicated that on days SGMY experienced external and internalized minority stressors, they reported greater intensity of suicidal and non-suicidal self-injurious ideation and affective distress (i.e., greater negative affect, lower positive affect, and more emotion dysregulation). Greater affective reactivity processes were associated with greater suicidal and non-suicidal self-injurious ideation intensity on the same day. Most of the within-person associations between external and internalized minority stressors and ideation intensity were mediated by heightened negative affect and emotion dysregulation but not lower positive affect. Our results provide the first evidence of these associations among SGMY, advance the minority stress model, and have implications for clinical interventions as we identified modifiable affective mechanisms.
On days sexual and gender minority youth experience greater than their usual minority stressors, such as discrimination, microaggressions, identity concealment and internalized stigma, they report greater intensity of their thoughts of suicide and non-suicidal self-injury and more emotional distress and dysregulation (i.e., greater negative affect, lower positive affect, and more emotion dysregulation). Emotional distress and dysregulation are also associated with greater intensity of thoughts of suicide and non-suicidal self-injury on the same day. The within-person associations minority stressors and intensity of thoughts of suicide and non-suicidal self-injury were mostly accounted for by negative affect and emotion dysregulation but not positive affect.
Alcohol dependence (AD) affects individuals from all racial/ethnic groups and previous research suggests that there is considerable variation in AD among ethnic minority groups in the United States. ...Although the reasons for these differences are likely due, in part, to contributions of complex sociocultural factors, limited research has attempted to examine whether similar genetic variation plays a role within both ancestral groups. Using a pooled sample of individuals of African and European ancestry (AA/EA) obtained through data shared within the Database for Genotypes and Phenotypes (dbGAP), we estimated the extent of additive genetic similarity for AD between AA and EAs using common single nucleotide polymorphisms (SNPs) that overlapped across the two populations. AD was represented as a factor score using Diagnostic and Statistical Manual (DSM-IV) dependence criteria and genetic data was imputed using the 1000 Genomes Reference Panel. Analyses revealed a significant SNP-based heritability of 22% (SE=5%) in EAs and 27% (SE=13%) in AAs. Further, a significant genetic correlation of 0.77 (SE=0.46) suggests that the allelic architecture influencing the AD factor for EAs and AAs is largely similar across the two populations. Follow-up analysis indicated that investigating the genetic underpinnings of alcohol dependence in different ethnic groups may serve to highlight etiological influences that are otherwise missed.
Exposure to traumatic experiences is associated with an increased risk for drug dependence and poorer response to substance abuse treatment (Claus & Kindleberger, 2002; Jaycox, Ebener, Damesek, & ...Becker, 2004). Despite this evidence, the reasons for the observed associations of trauma and the general tendency to be dependent upon drugs of abuse remain unclear. Data (N = 2,596) from the Study of Addiction: Genetics and Environment were used to analyze (a) the degree to which commonly occurring single nucleotide polymorphisms (SNPs; minor allele frequency > 1%) in the human genome explains exposure to interpersonal traumatic experiences, and (b) the extent to which additive genetic effects on trauma are shared with additive genetic effects on drug dependence. Our results suggested moderate additive genetic influences on interpersonal trauma, h2SNP-Interpersonal = .47, 95% confidence interval (CI) .10, .85, that are partially shared with additive genetic effects on generalized vulnerability to drug dependence, h2SNP-DD = .36, 95% CI .11, .61; rG-SNP = .49, 95% CI .02, .96. Although the design/technique does not exclude the possibility that substance abuse causally increases risk for traumatic experiences (or vice versa), these findings raise the possibility that commonly occurring SNPs influence both the general tendency towards drug dependence and interpersonal trauma. Resumen La exposición a experiencias traumáticas está asociada con un aumento en el riesgo de una dependencia a drogas y una peor respuesta al tratamiento de abuso de sustancias (Claus & Kindleberger, 2002; Jaycox, Ebener, Damesek, & Becker, 2004). A pesar de esta evidencia, la razón para la asociación observada entre trauma y tendencia general a ser dependiente del abuso de drogas aún es incierta. En los datos (N = 2,596) del estudio de adicciones: la genética y el ambiente fueron utilizados para analizar (a) el grado en que la ocurrencia común de polimorfismos de nucleótidos únicos (SNPs; frecuencia del alelo menor > 1%) en el genoma humano explica la exposición a experiencias interpersonales traumáticas, y (b) el grado para determinar cuales efectos de genética aditiva sobre trauma se comparten con efectos de genética aditiva sobre la dependencia de drogas. Nuestros resultados sugieren influencias moderadas de la genética aditiva sobre trauma interpersonal (h2SNP-Interpersonal 95% intervalo de confianza = .47.10, .85) los cuales son parcialmente compartidos con los efectos de la genética aditiva sobre la vulnerabilidad generalizada hacia la dependencia a drogas (h3SNP-DD = .36-11.-61: rG-SNP = .49 .02, .96). A pesar de que el diseño/técnica no excluye la posibilidad de que el abuso de sustancias aumente causalmente el riesgo de experiencias traumáticas (o viceversa), estos resultados implican la posibilidad de que SNPs de común ocurrencia influencien tanto la tendencia general hacia la dependencia de drogas como el trauma interpersonal.
PDF
