Johannes H. Smit

We tested for interactions between body mass index (BMI) and common genetic variants affecting serum urate levels, genome-wide, in up to 42569 participants. Both stratified genome-wide association (GWAS) analyses, in lean, overweight and obese individuals, and regression-type analyses in a non BMI-stratified overall sample were performed. The former did not uncover any novel locus with a major main effect, but supported modulation of effects for some known and potentially new urate loci. The latter highlighted a SNP at RBFOX3 reaching genome-wide significant level (effect size 0.014, 95% CI 0.008-0.02, Pinter= 2.6 x 10-8). Two top loci in interaction term analyses, RBFOX3 and ERO1LB-EDARADD, also displayed suggestive differences in main effect size between the lean and obese strata. All top ranking loci for urate effect differences between BMI categories were novel and most had small magnitude but opposite direction effects between strata. They include the locus RBMS1-TANK (men, Pdifflean-overweight= 4.7 x 10-8), a region that has been associated with several obesity related traits, and TSPYL5 (men, Pdifflean-overweight= 9.1 x 10-8), regulating adipocytes-produced estradiol. The top-ranking known urate loci was ABCG2, the strongest known gout risk locus, with an effect halved in obese compared to lean men (Pdifflean-obese= 2 x 10-4). Finally, pathway analysis suggested a role for N-glycan biosynthesis as a prominent urate-associated pathway in the lean stratum. These results illustrate a potentially powerful way to monitor changes occurring in obesogenic environment.

The Netherlands Study of Depression and Anxiety (NESDA) is a multi-site naturalistic cohort study to: (1) describe the long-term course and consequences of depressive and anxiety disorders, and (2) to integrate biological and psychosocial research paradigms within an epidemiological approach in order to examine (interaction between) predictors of the long-term course and consequences. Its design is an eight-year longitudinal cohort study among 2981 participants aged 18 through 65 years. The sample consists of 1701 persons with a current (six-month recency) diagnosis of depression and/or anxiety disorder, 907 persons with life-time diagnoses or at risk because of a family history or subthreshold depressive or anxiety symptoms, and 373 healthy controls. Recruitment took place in the general population, in general practices (through a three-stage screening procedure), and in mental health organizations in order to recruit persons reflecting various settings and developmental stages of psychopathology. During a four-hour baseline assessment including written questionnaires, interviews, a medical examination, a cognitive computer task and collection of blood and saliva samples, extensive information was gathered about key (mental) health outcomes and demographic, psychosocial, clinical, biological and genetic determinants. Detailed assessments will be repeated after one, two, four and eight years of follow-up. The findings of NESDA are expected to provide more detailed insight into (predictors of) the long-term course of depressive and anxiety disorders in adults. Besides its scientific relevance, this may contribute to more effective prevention and treatment of depressive and anxiety disorders.

BACKGROUND: Comorbidity of depressive and anxiety disorders is common and has been shown to be a consistent predictor of chronicity. Comorbidity patterns among specific depressive and anxiety disorders have not been extensively reported. This study examines comorbidity patterns and temporal sequencing of separate depressive and anxiety disorders using data from a large psychiatric cohort. METHOD: Baseline data (N = 1,783) of the Netherlands Study of Depression and Anxiety, collected between September 2004 and February 2007, were used. Current and lifetime comorbidity rates for depressive and anxiety disorders (DSM-IV-TR criteria) were calculated. Associations of comorbidity with sociodemographic, vulnerability, and clinical characteristics, and temporal sequencing of disorders were examined. RESULTS: Of those with a depressive disorder, 67% had a current and 75% had a lifetime comorbid anxiety disorder. Of persons with a current anxiety disorder, 63% had a current and 81% had a lifetime depressive disorder. Comorbidity of depressive and anxiety disorders was associated with more childhood trauma (OR = 1.19; 95% CI, 1.06-1.33), higher neuroticism (OR = 1.05; 95% CI, 1.02-1.08), earlier age at onset of first disorder (OR = 1.59; 95% CI, 1.22-2.07), longer duration of depressive and/or anxiety symptoms (OR = 1.01; 95% CI, 1.01-1.01), and higher symptom severity (ORs ranging from 1.01 to 1.03; all P values < .05). In 57% of comorbid cases, anxiety preceded depression, and in 18%, depression preceded anxiety. Comorbidity with preceding depression compared to preceding anxiety was associated with a shorter duration of symptoms of depressive and/or anxiety symptoms (OR = 0.99; 95% CI, 0.98-0.99), earlier age at first onset (OR = 0.46; 95% CI, 0.31-0.68), and fewer fear symptoms (OR = 0.98; 95% CI, 0.97-0.99). CONCLUSIONS: Comorbidity rates in anxiety and depressive disorders were very high, indicating that it is advisable to assess both disorders routinely regardless of the primary reason for consultation. This is especially important since comorbid patients showed a specific vulnerability pattern, with more childhood trauma, neuroticism, and higher severity and duration of symptoms.