Gilles de la Tourette Syndrome and Obsessive Compulsive Disorder in Childhood-A Community Based Epidemiological and Family Study

Grant Type
Grant Year
Institution Location
Institution Organization Name
University College of London UK
Investigators Name
Eapen, Valsamma, MBBS, DPM, MR

We are delighted to be embarking on an epidemiological study to ascertain the prevalence of Tics, Tourette Syndrome (TS) and Obsessive Compulsive Disorder (OCD), in a community based sample. This study •will establish how common these disorders are. We will then study, in detail, the subjects thus identified, to determine the nature of these conditions, as well as the presence of TS associated behaviors. In order to understand more about the genetic nature and inter-relationships among these disorders, we hope to compare and contrast the findings from this community based study with that of data from our clinic based samples. Sample selection bias affects both the prevalence estimates of TS and those of the degree and nature of the relationship between TS and associated conditions. To date, most studies have been based on targeted populations (e.g. clinics, schools). However, it is well known that patients in treatment for any disorder are not always representative of those in the general population because often they are more severely affected and frequently have co-existing disorders. Therefore, generalizing from a clinical setting to the general population can be misleading. It is generally accepted (as family studies have shown) that many of the available figures are underestimates, and that for every single diagnosed case in the clinic there are many more undiagnosed cases in the community. There is some controversy about which of several associated behaviors (e.g. OCD, ADHD) is genetically related to TS. Moreover, OCD and ADHD are common during childhood. Individuals seen in the clinics are more likely to have associated conditions, and the pattern of occurrence of these conditions in families seen in the clinics may not be an accurate reflection of the general population. Increasingly it is becoming recognized that there may be a familial pattern to the inheritance of OCD (“pure OCD” not related to TS). In addition, there are some forms of OCD seen in TS subjects that may be an alternative way that the TS gene expresses itself. It might be that there are subgroups within OCD: those with a family history of tics or TS, and those without. If this is so, it may be argued that there are differences between the two groups at a genetic, symptomatic or biochemical level. However, all the available data so far are limited because the studies have been conducted in clinic samples. That is why we plan to study these disorders in the general community. Once we have identified cases of TS from the general community, we will examine whether patterns in families are related to severity and comorbidity (multiple problems coexisting). Also, we hope to determine whether the patterns in these families are similar to those observed in families of clinic subjects. It will then be possible to learn more about the underlying mechanisms for TS, OCD, and ADHD and the relationship among these conditions. Valsamma Eapen, MBBS, DPM, MRCPsych; Prof. Harold Zeitlin, BSc, MPhil, MD, FRCP, FRC;Psych Mary M. Robertson, MBChB, MD, DPM, FRC Psych University College London Medical School, Harlow, England Award $22,000 Tourette Association of America Inc. – Research Grant Award 1994