Obsessive-Compulsive Disorder in Patients with Mild Cognitive Impairment: A Comparative Study with Healthy Older Adults.

BACKGROUND

Mild cognitive impairment is considered a prodromal state and a risk factor for dementia. To the best of our knowledge, no previous studies have examined the relationship between obsessive-compulsive disorder and mild cognitive impairment. One of the risk factors for the development of mild cognitive impairment may be obsessive-compulsive disorder. In this study, we hypothesized that the patients with mild cognitive impairment had a significantly higher rate of obsessive-compulsive disorder than healthy elders, and some types of preexisting obsessive-compulsive symptoms may be associated with mild cognitive impairment.

METHODS

A total of 66 subjects (mild cognitive impairment = 35; healthy elderly = 31) were assessed for severity of cognitive impairment using the Mini-Mental State Examination, Clinical Dementia Rating Scale, and Addenbrooke's Cognitive Examination III tests. Lifetime diagnosis of obsessive-compulsive disorder was assessed through Structured Clinical Interview of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I disorders. The severity of the obsessive-compulsive disorder and the content of previous obsessive-compulsive symptoms were measured by Yale-Brown Obsessive-Compulsive Scale.

RESULTS

Mild cognitive impairment patients had more previous depressive episodes and a lifetime diagnosis of obsessive-compulsive disorder when compared with healthy subjects, P  = .023. Educational level was significantly lower in mild cognitive impairment patients than in healthy elders, P  = .037. The contamination obsessions and cleaning and checking compulsions were significantly higher in the patients with mild cognitive impairment than in healthy subjects, P  = .044. Hamilton Anxiety Rating Scale and Hamilton Depression Rating Scale scores were significantly higher in patients with mild cognitive impairment, P  = .009 and P  = .045 respectively. Lower educational level, previous obsessive-compulsive disorder, Hamilton Anxiety Rating Scale and Hamilton Depression Rating Scale scores, and checking compulsions significantly predicted the patients with mild cognitive impairment, P  = .044.

CONCLUSION

Our findings may demonstrate that lower educational level, previous obsessive-compulsive disorder, checking compulsions, and current anxiety and depression severity appeared significantly associated with mild cognitive impairment. We suggest that previous obsessive-compulsive disorder and checking obsessive-compulsive symptoms may be related to earlier stages of memory dysfunction.