A Family Study of Juvenile Obsessive-Compulsive Disorder

P Srinivas Reddy, DPM, DNB1, YC Janardhan Reddy, MD, DPM2, S Srinath, MD, DPM3, S Khanna MD, DPM, PhD, MRCPsych3, SP Sheshadri, MD, DPM3, SR Girimaji, MD3

Objective: To determine  whether juvenile obsessive–compulsive disorder (OCD) is familial and whether the rate of Tourette syndrome (TS) and tic disorders is higher among relatives of patients with OCD than among relatives of controls subjects.
Method: We assessed first-degree relatives of 35 juvenile OCD probands (aged 16 years or less) and 34 matched, psychiatrically unaffected control subjects, using the Diagnostic Interview for Children and Adolescents–Revised (DICA-R) (unpublished), a Questionnaire for tic disorders, the Children’s Version of Leyton’s Obsessional Inventory (CV-LOI), and the Children’s Version of the Yale-Brown Obsessive Compulsive Scale (CY-BOCS). Similarly, we assessed adult relatives, using the Schedule for Clinical Assessment in Neuropsychiatry (SCAN), Leyton’s Obsessional Inventory (LOI), the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), and a Questionnaire for tic disorders. The diagnoses were determined by consensus, using DSM-III-R criteria. We calculated age-corrected morbid risk, using Weinberg’s method.
Results: The morbid risk for OCD among the relatives of OCD probands was 4.96%, while none of the relatives of unaffected control subjects had OCD. We did not diagnose TS in any of the relatives of either OCD probands or control subjects. We diagnosed chronic motor tic disorders in only 1 of the relatives of OCD probands, while none of the relatives of control subjects had any tic disorder.
Conclusions: Most juvenile cases of OCD are nonfamilial and unrelated to tic disorders, while only a few are familial. There is a need to re-examine the issue of familiality in cases of OCD, as well as its relation to TS, using larger community samples to better understand the hypotheses of familial transmission and comorbidity with tic disorders.

(Can J Psychiatry 2001;46:346-351)

Key Words: genetic, familial, obsessive-compulsive disorder, children, adolescents

The familial nature of obsessive–compulsive disorder (OCD) has been described since the 1930s (1–14), but the subject remains controversial. While some early family studies reported findings that support the familial nature of OCD (1–4,8), others found no increase in the rates of OCD among first-degree relatives (5–7). Many earlier studies are, however, difficult to interpret because of differences in diagnostic criteria and methods of assessment. Most studies did not directly interview relatives and lacked control groups.

In some recent studies, the methodological shortcomings of the earlier studies have been addressed by directly interviewing relatives and employing standard diagnostic criteria (9–16). Three of the studies (9–11) reported a morbidity risk of 13% to 36% in families having children with OCD. A

Manuscript received April 2000, revised, and accepted March 2001.
1Research Associate, The Department of Psychiatry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bangalore, India.
2Associate Professor of Psychiatry, The Department of Psychiatry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bangalore, India.
3Additional Professor of Psychiatry, The Department of Psychiatry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bangalore, India.
Address for correspondence: Dr YC Janardhan Reddy, Department of Psychiatry, NIMHANS, Hosur Road, Bangalore–560 029, India.
E-mail: jreddy@nimhans.kar.nic.in

major methodological weakness of all 3 studies was the lack of a comparison group. The study by Pauls and others (14), which included a comparison group, reported a higher risk for OCD (20%) among the relatives of probands with early-onset OCD (less than age 18 years) than among those with late-onset OCD (11%), whilein relatives of the psychiatrically unaffected comparison group, the rate was 1.9%. Interestingly, 2 studies found evidence for familiality only in relatives of early-onset probands (12,16). All these studies strongly support the possible familial component for the expression of OCD, particularly childhood- and adolescent-onset OCD.

Additional support for the role of familial factors in the expression of CD comes from the finding of high rates of OCD among relatives of probands with Tourette syndrome (TS) (15,17–19). Similarly, high rates of tic disorders and TS have been reported among relatives of OCD probands (11,14), suggesting that some forms of OCD may be etiologically (and perhaps genetically) related to TS.

While many studies report increased rates of OCD in relatives of OCD probands (9–12,14–16), findings of some studies do not support the familial nature of OCD (13,20). The study by Black and others (13) found no evidence that OCD was familial, and they concluded that an anxiety diathesis rather than than OCD per se may be inherited. A family study from our centre (20), which examined 135 adult first-degree relatives of 35 adults with OCD and 148 adults from the general population, found no evidence for familiality.

Next