Obsessive-compulsive disorder (OCD) was described as early as the seventeenth century, when the Oxford Don, Robert Burton, reported a case in his compendium, The Anatomy of Melancholy (1621). Modern concepts of OCD began to evolve in France and Germany in the nineteenth century. In the late twentieth century we have begun to understand the biology of this mental disorder, as neurochemical assay and brain imaging techniques have become available.
Age at Onset
OCD usually begins before age 25 years and often in childhood or adolescence. In individuals seeking treatment, the mean age of onset appears to be somewhat earlier in men than women. According to Swedo et al.'s report in 1989, in a series of 70 children and adolescents seen at the National Institute of Mental Health, the mean age of onset was 9.6 years for boys and 11.0 for girls. In a series of 263 adult and child patients, Lensi et al. in 1996 reported that the mean age at onset was 21 years for men and 24 years for women. Still, in another series reported by Rasmussen and Eisen in 1992, the means were 21 years for men and 22 years for women -- in this series, major symptoms began before age 15 years in about one-third, before age 25 in about two-thirds, and after age 35 in less than 15%.
In one series of 200 patients reported by Rasmussen and Eisen in 1988, 29% felt that an environmental precipitant had triggered their illness, most frequently increased responsibility, such as the birth of a child, or significant losses, such as a death in the family, while Williams and Koran reported in 1997 that of 100 women in their study, 62% reported premenstrual worsening.
In community surveys, the results are mixed. The Epidemiological Catchment Area survey (ECA), which utilized lay interviewers (trained non-professionals) to examine more than 18,500 individuals in five cities reported a similar mean age of onset for men and women identified as OCD cases (22.4 and 23.0 years). A similar study in Edmonton, Canada reported a slightly later median age of onset for males (age 20 years) than females (age 19 years). Among 56 individuals in their mid-20s with obsessive-compulsive syndrome identified in a Zurich survey, the mean age of onset was 17 years for males and 19 years for females.
Course and Prognosis
For most adult patients who come to treatment, OCD appears to be a chronic condition. In their series of 560 patients in 1988, Rasmussen and Eisen reported that 85% had a continuous course with waxing and waning symptoms, 10% a deteriorative course and only 2% an episodic course marked by full remissions lasting six months or more. An Italian series by Lensi et al. in 1996 reported more patients with episodic or deteriorative courses in which 26% were episodic, 9% were deteriorative, and 64% were chronic. The conclusions drawn from studies that predate current diagnostic criteria, effective treatments and current patterns of health care utilization should not be applied to today's patients.
The prognosis of children and adolescents who present for treatment appears to be good for half or more. Leonard et al. reported in 1993, that a little more than half of 54 children and adolescents were only mildly affected when evaluated two- to seven- years after vigorous treatment with medications, and less often with behavior therapy. Only six patients (11%) were symptom free, however, and only three of these were taking no medication. A 9 -to 14 -year follow-up study reported that 8 of 14 adolescents who had received medication treatment were medication free and did not meet OCD criteria; the other six had experienced a chronic, or a relapsing and then chronic course, reported Bolton, Luckie and Steinberg in 1995. Finally, Thomsen and Mikkelsen reported in 1995 that a 1.5 to 5 year follow-up of 23 children and adolescents who had recieved drug treatment found that four were free of OCD, eight had subclinical symptoms and the remaining 11 had chronic or episodic OCD. Larger studies from multiple sites are needed to establish accurately the prognosis associated with modern treatment methods.
In community-identified cases, remission, or a course marked by long, symptom-free periods, seems to be the rule. The apparent frequency of this benign course is probably due to the limited diagnostic validity of interviews conducted by lay interviewers and to the large proportion of milder cases in community sample. According to Nelson and Rice in 1997, only 19% (56 of 291 subjects) meeting OCD criteria during their first lay inerview met these criteria duing a lay interview conducted one year later.
Patients with OCD are at high risk of having comorbid (co-existing) major depression and other anxiety disorders. In a series of 100 OCD patients who were evaluated by means of a structured psychiatric interview, the most common concurrent disorders were: major depression (31%), social phobia (11%), eating disorder (8%), simple phobia (7%), panic disorder (6%), and Tourette's syndrome (5%). In Koran et al.'s 1998 Kaiser Health Plan study, 26% of patients had no comorbid psychiatric condition diagnosed during the one year study period -- 37% had one and 38% had two or more comorbid conditions. These proportions did not differ substantially between men and women. The most commonly diagnosed comorbid conditions were major depression, which affected more than one-half, other anxiety disorders, affecting one-quarter, and personality disorders, diagnosed in a little more than 10%. Panic disorder and generalized anxiety disorder were the most common anxiety disorders. Bipolar mood (manic-depressive) disorder was uncommon, but schizophrenia was rare. Except for eating disorders, which were diagnosed in 1 in 20 women, the rates of specific comorbid conditions were not strkingly different between men and women.
OCD seems to be associated with a mildly increased risk for alcohol abuse and dependence. Rates of OCD observed among alcoholic patients admitted to inpatient and outpatient treatment programs exceed the rate in the general population, but not to the extent suggested by Karno et al.'s study in 1988, which attributed alcohol abuse or dependence to 24% of OCD subjects.
Reports of the lifetime rate of body dysmorphic disorder (fear of imagined ugliness) in OCD patients are also prevalent, as well as findings by Barsky in 1992 indicating that patients with hypochondriasis have an elevated lifetime prevalence rate of OCD compared to medical outpatients from the same clinic. Eating disorders may be more common in OCD patients than in the general population, but the data are sparse. According to Rothenberg in 1990, OCD symptoms are common in patients with anorexia nervosa, second only to depressive disorders. Trichotillomania (compulsive hair pulling with bald spots) is another comorbidity of OCD, as is Tourette's syndrome (the combination of behavioral and vocal tics).
Quality of Life
OCD impairs patients' quality of life. In a study of 60 patients, Koran, Thienemann and Davenport reported in 1996 that medication-free patients with moderate to severe OCD reported worse social functioning and performance in work and other activities than the general population and than patients with diabetes. The more severe the OCD, the more impaired the patients' social functioning, even after controlling for effects of concurrent depression. Moreover, Rasmussen and Eisen noted in 1992 that another indicator of reduced quality of life is lower likelihood of OCD patients marrying.
The high personal cost of OCD is mirrored in high social costs. The estimated 1990 direct costs of OCD to the United States economy were $2.1 billion, and the indirect cost (i.e., lost productivity) $6.2 billion, reported Dupont et al. in 1995. If a greater proportion of individuals with OCD were in treatment, the direct costs would have been considerable higher. For example,according to Nestadt et al. in 1994, among a random sample of the Baltimore study participants, only 1 of 15 individuals (7%) whom a psychiatrist judged to need treatment was receiving it. Rasmussen and Eisen reported in 1988 that the delay between symptom onset and first seeking care is often prolonged by a mean of seven years, while Marks in 1992 reported 10 years. Even with much treatment foregone, OCD accounted for almost 6% of the estimated 1990 cost of all mental illness. High social costs are also reflected in the high rates of unemployment in OCD patients and receipt of disability and welfare payments, reported Leon, Portera and Wissman in 1995. Family members suffer as well. Many studies indicate that patients' symptoms may create disharmony, angry or anguished demands for participating in rituals, a draining dependency, restricted access to rooms or living space, difficulty in taking holidays and intereference with work obligations.