Search

Background: Social Anxiety Disorder (SAD) is a relatively frequent psychiatric disorder, with a lifetime prevalence of about 4% [1], which usually starts in adolescence [2]. As in the case of other mental disorders, [3] SAD has also been linked to academic impairment and school drop-out [4,5], but this previous research has a number of methodological limitations, mainly the use of modest sample sizes, retrospective designs, self-reported measures, and focusing in a single educational level. Aim: We aim to investigate the association between SAD and educational outcomes at all levels using objectively collected measures, controlling for a number of covariates and unmeasured factors shared between siblings. Method: Using the Swedish nationwide registers, we designed this population-based birth cohort study, which included 2,244,191 individuals born in Sweden between 1973 and 1997, who were followed up from 1991 until 2013. A total of 15,765 individuals had a record of SAD in the Swedish National Patient Register, according to the International Classification of Diseases, 10th edition. Logistic regression models tested the association between SAD and the prospectively-collected and objectively measured educational outcomes. These educational milestones included: the year grades in the final year of compulsory school, the eligibility to access upper secondary school after compulsory education (for both, vocational and academical programs), finishing upper secondary school, starting university, finishing a university degree, and completing post-graduate education. In order to reduce the impact of possible confounders, we took into account a number of covariates such as age, sex, maternal and paternal age at birth and year of birth. The impact of common psychiatric comorbidities of SAD was also taken into account. In order to control for unmeasured shared familial factors, we performed a sibling comparison analysis. We identified 786,766 families with 2 or more siblings

The association between obsessive-compulsive disorder (OCD) and Tourette's/chronic tic disorders (TD/CTD) with autoimmune diseases (ADs) is uncertain. In this nationwide study, we sought to clarify the patterns of comorbidity and familial clustering of a broad range of ADs in individuals with OCD, individuals with TD/CTD and their biological relatives. From a birth cohort of 7 465 455 individuals born in Sweden between 1940 and 2007, we identified 30 082 OCD and 7279 TD/CTD cases in the National Patient Register and followed them up to 31 December 2013. The risk of 40 ADs was evaluated in individuals with OCD, individuals with TD/CTD and their first- (siblings, mothers, fathers), second- (half siblings) and third-degree (cousins) relatives, compared with population controls. Individuals with OCD and TD/CTD had increased comorbidity with any AD (43% and 36%, respectively) and many individual ADs. The risk of any AD and several individual ADs was consistently higher among first-degree relatives than among second- and third-degree relatives of OCD and TD/CTD probands. The risk of ADs was very similar in mothers, fathers and siblings of OCD probands, whereas it tended to be higher in mothers and fathers of TD/CTD probands (compared with siblings). The results suggest a familial link between ADs in general (that is, not limited to Streptococcus-related conditions) and both OCD and TD/CTD. Additional mother-specific factors, such as the placental transmission of antibodies, cannot be fully ruled out, particularly in TD/CTD., Funding Agencies:Tourette Association of AmericaAlicia Koplowitz FoundationNIMH R01MH105500 R01MH110427Swedish Research Council through the SIMSAM (Swedish Initiative for Research on Microdata in the Social And Medical Sciences) 340-2013-5867

BACKGROUND: We aimed to provide unbiased estimates of familial risk and heritability of social anxiety disorder (SAD) and avoidant personality disorder (AVPD). METHOD: We identified 18 399 individuals diagnosed with SAD and 2673 with AVPD in the Swedish National Patient Register between 1997 and 2009. Risks (odds ratios; OR) for SAD in all biological and non-biological relatives of probands, compared to relatives of unaffected individuals were calculated. We also estimated the risks for AVPD in relatives of probands with SAD. RESULTS: The risk for SAD among relatives of SAD probands increased proportionally to the degree of genetic relatedness. The risks for first-degree relatives [OR 4.74, 95% confidence interval (CI) 4.28-5.25] were significantly higher than for second-degree and third-degree relatives. Second-degree relatives (OR 2.30, 95% CI 2.01-2.63) had significantly higher risk than third-degree relatives (OR 1.72, 95% CI 1.52-1.94). Relatives at similar genetic distances had similar risks for SAD, despite different degrees of shared environment. Heritability was estimated to be approximately 56%. There were no significant sex differences in the familial patterns. The risk of AVPD in relatives of SAD probands was significantly elevated, even after excluding individuals with both diagnoses (first-degree OR 3.54, second-degree OR 2.20, third-degree OR 1.62). Non-biological relatives (spouses/partners) also had elevated risks for both SAD (OR 4.01) and AVPD (OR 3.85). CONCLUSIONS: SAD clusters in families primarily due to genetic factors. SAD and AVPD are aetiologically related and may represent different expressions of the same vulnerability. The strong marital concordance observed in SAD/AVPD may indicate assortative mating but the exact mechanisms and implications require further investigation.