title: Is late-onset OCD a distinct phenotype? Findings from a comparative analysis of "age at onset" groups.
abstract: OBJECTIVE
  Significant differences in clinical profile and comorbidity patterns have been observed between "juvenile-onset" and "adult-onset" obsessive-compulsive disorder (OCD). There is little systematic research on onset of OCD after the fourth decade. The current study aims to compare the demographic, clinical, and comorbidity patterns of patients with "juvenile-onset" (<18 years), "adult-onset" (18-39 years), and "late-onset" (≥40 years) OCD.
  
  
  METHODS
  Eight hundred two consecutive patients who consulted a specialty OCD clinic at a tertiary care hospital in India were evaluated with the Mini International Neuropsychiatric Interview, the Yale-Brown Obsessive-Compulsive Scale, and the Clinical Global Impression scale.
  
  
  RESULTS
  37.4%, 57.4%, and 5.2% of patients had juvenile-, adult-, and late-onset OCD, respectively. Late-onset OCD was associated with female gender (χ2=42, p<0.001); negative family history of OCD in first-degree relatives (χ2=20.4, p<0.001); and less aggressive obsessions (χ2=18.16, p<0.001), sexual obsessions (χ2=26.68, p<0.001), pathological doubts (χ2=19.41; p<0.001), and repeating rituals (χ2=44.28; p<0.001). On multinomial logistic regression, late-onset OCD was significantly associated with female gender, collecting compulsions, and less aggressive obsessions, in comparison with adult-onset OCD. In comparison with juvenile-onset, late-onset OCD was significantly associated with female gender, presence of precipitating factors, and less aggressive obsessions, sexual obsessions, and repeating compulsions.
  
  
  CONCLUSIONS
  Late-onset OCD is characterized by female gender, lesser familial loading for OCD, and presence of precipitating factors, suggesting that it may have a distinct pathophysiology compared to juvenile- and adult-onset OCD. Systematic research is required to understand the family-genetic, neuropsychological, and neurobiological correlates of late-onset OCD.
authors.affiliation: 1Department of Psychiatry,King George Medical University,Lucknow,Uttar Pradesh,India.
authors.forename: Eesha
authors.initials: E
authors.lastname: Sharma
authors.affiliation: 2Department of Psychiatry,National Institute of Mental Health and Neurosciences,Bangalore,Karnataka,India.
authors.forename: A Shyam
authors.initials: AS
authors.lastname: Sundar
authors.affiliation: 2Department of Psychiatry,National Institute of Mental Health and Neurosciences,Bangalore,Karnataka,India.
authors.forename: Kandavel
authors.initials: K
authors.lastname: Thennarasu
authors.affiliation: 2Department of Psychiatry,National Institute of Mental Health and Neurosciences,Bangalore,Karnataka,India.
authors.forename: Y C Janardhan
authors.initials: YC
authors.lastname: Reddy
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009771:Obsessive-Compulsive Disorder / Q000523:psychology*; D010641:Phenotype; D011569:Psychiatric Status Rating Scales; D055815:Young Adult
keywords: Age at onset; classification; gender; late-onset; obsessive compulsive disorder