Obsessive-compulsive spectrum disorders and rheumatic fever: a family study.

Author(s)

Ana Gabriela Hounie

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2003-08-20

Examining board members

Euripedes Constantino Miguel Filho; Beny Lafer; Homero Pinto Vallada Filho; Mayana Zatz

• Advisor: Euripedes Constantino Miguel Filho

Abstract

Summary Hounie, A.G. Obsessive-compulsive spectrum disorders and rheumatic fever: a family study. São Paulo, 2003. 174p. Tese (Doutorado) – Faculdade de Medicina, Universidade de São Paulo. Rheumatic fever (RF) is an autoimmune disease caused by antibodies against group A beta hemolytic streptococcus (GABHS). Some studies support the notion that RF be associated with obsessive-compulsive disorder (OCD) independent of its manifestations on the central nervous system (eg., Sydenham’s Chorea - SC). OCD is often accompanied by other disorders, which are known as obsessive-compulsive spectrum disorders (OCSD), such as Tourette syndrome (TS), chronic tic disorder (CTD) and body dysmorphic disorder (BDD). Some of those putative OCSD seem to share a genetic relationship. An OCD subgroup is genetically related to TS, being considered an alternative phenotype. A recent OCD family study found higher rates of BDD and tic disorders among first-degree relatives (FDR) of OCD probands. This is a family study that assessed the frequency of OCD and OCSD in first-degree relatives of RF probands (with and without SC) in order to verify if there was aggregation of those disorders in RF families. We assessed 98 probands and their 381 first-degree relatives. Of the 98 probands, 31 had RF without SC, 28 had RF with SC and 39 were controls without RF recruited in an orthopedic clinic. Trained interviewers assessed subjects with semi-structured interviews (KSADS and SCID). Clinical vignettes were elaborated and evaluated by independent psychiatrists that assigned best estimate diagnosis. These raters were blind to subject status regarding group and if they were probands or relatives. Comparisons between frequencies of disorders were done with Fisher and chi-square tests, generalized estimated equations (GEE), and Kaplan-Meier survival analyses. Results were considered statistically significant if their level of significance was less or equal to 0.05 (p, two-tailed). OCSD combined were more frequent in FDR of RF probands (with or without SC) than in FDR of controls (p=0.03). CTD was more frequent in FDR of SC probands than FDR of controls (p=0.05). Generalized anxiety disorder (GAD) was more frequent in FDR of RF probands than in FDR of controls (p=0.008). Subdividing probands based on the presence of an OCSD, tic disorders combined (GEE, p=0.01), BDD (GEE, p=0.02), GAD (x2=0.004), and OCSD combined (GEE, p=0.02) were more frequent in FDR of RF probands with an OCSD than in FDR of controls. OCSD were also more frequent (non-significantly, p=0.09) in FDR of RF probands without an OCSD than in FDR of controls. RF in the probands increased the risk of OCSD in their family members. This risk was even higher if the proband had RF plus an OCSD. It is possible that a subgroup of RF is associated to OCSD and susceptibility factors linked to RF and to OCSD may have an additive effect. Therefore RF may be a risk factor for OCSD. (AU)