ABSTRACT
Background: Mood disorders such as major depressive and bipolar disorders, along with posttraumatic stress disorder (PTSD), schizophrenia (SCZ), and other psychotic disorders, constitute serious mental illnesses (SMI) and often lead to inpatient psychiatric care for adults. Risk factors associated with increased hospitalization rate in SMI (H-SMI) are largely unknown but likely involve a combination of genetic, environmental, and socio-behavioral factors. We performed a genome-wide association study in an African American cohort to identify possible genes associated with hospitalization due to SMI (H-SMI). Methods: Patients hospitalized for psychiatric disorders (H-SMI; n=690) were compared with demographically matched controls (n=4467). Quality control and imputation of genome-wide data were performed following the Psychiatric Genetic Consortium (PGC)-PTSD guidelines. Imputation of the Human Leukocyte Antigen (HLA) locus was performed using the HIBAG package. Results: Genome-wide association analysis revealed a genome-wide significant association at 6p22.1 locus in the ubiquitin D (UBD/FAT10) gene (rs362514, p=9.43x10-9) and around the HLA locus. Heritability of H-SMI (14.6%) was comparable to other psychiatric disorders (4% to 45%). We observed a nominally significant association with 2 HLA alleles: HLA-A*23:01 (OR=1.04, p=2.3x10-3) and HLA-C*06:02 (OR=1.04, p=1.5x10-3). Two other genes (VSP13D and TSPAN9), possibly associated with immune response, were found to be associated with H-SMI using gene-based analyses. Conclusion: We observed a strong association between H-SMI and a locus that has been consistently and strongly associated with SCZ in multiple studies (6p21.32-p22.1), possibly indicating an involvement of the immune system and the immune response in the development of severe transdiagnostic SMI.
ABSTRACT
OBJECTIVE: The development of depressive symptoms in youth with IBD is a concerning disease complication, as higher levels of depressive symptoms have been associated with poorer quality of life and lower medication adherence. Previous research has examined the association between disease activity and depression, but few studies have examined individual differences in experience of stressful life events in relation to depressive symptoms. The purpose of the current study is to examine the relation between stressful life events and depression within pediatric IBD and to determine whether individual differences in stress response moderates this association. METHODS: 56 youth ages 8-17 years old diagnosed with IBD completed questionnaires about their depressive symptoms and history of stressful life events. We assessed skin conductance reactivity (SCR) to a stressful task as an index of psychophysiological reactivity. RESULTS: Stressful life events (r = 0.36, p = .007) were positively related to depressive symptoms. Youth who demonstrated a greater maximum SC level during the IBD-specific stress trial compared to baseline (n = 32) reported greater depressive symptoms. For these same participants, the relationship between stressful life events and depressive symptoms depended on SCR F(3, 28) = 4.23, p = .01, such that at moderate and high levels of SCR, a positive relationship between stressful life events and depressive symptoms was observed. CONCLUSIONS: The relationship between stressful life events and depressive symptoms in youth with IBD may depend on individual differences in processing stress, such that risk may increase with greater psychophysiological reactivity.
