Register-based study of the incidence, comorbidities and demographics of obsessive-compulsive disorder in specialist healthcare.
Incidence of obsessive-compulsive disorder (OCD) has been suspected to increase but nationwide epidemiological studies are limited. This study aims to examine sex-specific incidence time trends and characterize psychiatric and neurodevelopmental comorbidities and sociodemographic risk factors of OCD in specialist healthcare in Finland.



A nationwide register-based study using data from four Finnish registers identified 3372 OCD cases and 13,372 matched controls (1:4). Cumulative incidence in subjects born between 1987 and 2001 was estimated at ages of 10, 15, 20 and 23 years. Conditional logistic regression was used to examine the sociodemographic factors.



The cumulative incidence of OCD was 0.4% by age 23. Incidence by age 15 among three cohorts increased from 12.4 to 23.7 /10000 live born males and 8.5 to 28.0 /10000 live born females. 73% of the sample had a comorbid condition. Males were significantly more comorbid with psychotic and developmental disorders; females were more comorbid with depressive and anxiety disorders (p <0.001). Higher maternal SES was associated with an increased risk of OCD (OR 1.4; 95% CI 1.1-1.6).



These findings suggest that incidence of treated OCD in specialist healthcare has increased. The reason may be increased awareness and rate of referrals but a true increase cannot be ruled out. Further research on risk factors of OCD is warranted.
Department of Child Psychiatry, University of Turku, Turku, Finland. hanna.rintala@utu.fi.|Research Centre for Child Psychiatry, Institute of Clinical Medicine, Faculty of Medicine, University of Turku, Lemminkäisenkatu 3 / Teutori (3rd floor), 20014, Turku, Finland. hanna.rintala@utu.fi.
Hanna
H
Rintala
Department of Child Psychiatry, University of Turku, Turku, Finland.|Research Centre for Child Psychiatry, Institute of Clinical Medicine, Faculty of Medicine, University of Turku, Lemminkäisenkatu 3 / Teutori (3rd floor), 20014, Turku, Finland.
Roshan
R
Chudal
Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland.
Sami
S
Leppämäki
Department of Child Psychiatry, University of Turku, Turku, Finland.|Department of Child Neurology, Helsinki University Central Hospital, Helsinki, Finland.|Research Centre for Child Psychiatry, Institute of Clinical Medicine, Faculty of Medicine, University of Turku, Lemminkäisenkatu 3 / Teutori (3rd floor), 20014, Turku, Finland.
Susanna
S
Leivonen
Department of Child Psychiatry, University of Turku, Turku, Finland.|Department of Child Psychiatry, University of Turku and Turku University Central Hospital, Turku, Finland.|Research Centre for Child Psychiatry, Institute of Clinical Medicine, Faculty of Medicine, University of Turku, Lemminkäisenkatu 3 / Teutori (3rd floor), 20014, Turku, Finland.
Susanna
S
Hinkka-Yli-Salomäki
Department of Child Psychiatry, University of Turku, Turku, Finland.|Department of Child Psychiatry, University of Turku and Turku University Central Hospital, Turku, Finland.|Research Centre for Child Psychiatry, Institute of Clinical Medicine, Faculty of Medicine, University of Turku, Lemminkäisenkatu 3 / Teutori (3rd floor), 20014, Turku, Finland.
Andre
A
Sourander
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008511:Medicine / Q000706:statistics & numerical data; D001523:Mental Disorders / Q000453:epidemiology*; D009771:Obsessive-Compulsive Disorder / Q000453:epidemiology*; D012042:Registries; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult
Comorbidity; Mental health services; Obsessive-compulsive disorder; Register-based study; Time trends of incidence