Throughout history, our conceptualization of obsessive compulsive disorder (OCD) has been changing alongside changes in the way we have viewed the world. With the dawning of the Renaissance in Western Europe, religious explanations based on demonic possession were superseded by a more humanistic understanding. By the early seventeenth century, the obsessions that drove Shakespeare’s Lady Macbeth to suicide were recognized to be a product of her guilty mind, for which there was no medical cure.
Obsessions and compulsions were first described in the medical literature of the early nineteenth century. They were viewed as an unusual expression of melancholia. By the beginning of the twentieth century, with the development of psychoanalysis, the focus shifted onto psychological explanations based on unconscious conflicts, but this did not provide a useful strategy for treatment. The subsequent application of learning theory to OCD led to the development of effective behavioural treatments in the 1960s and 1970s.
Compared with the pace of these historical developments, modern understanding of OCD has expanded with dramatic speed. The development of effective medical treatments of OCD has revolutionized the outlook for sufferers and propelled OCD to the forefront of scientific attention. With the growth of research into the epidemiology, psychopharmacology, neurobiology, neuropsychology and genetics of OCD, reviewed throughout this publication, the emphasis has once again swung back toward a medical model. As we enter the twenty-first century, we now recognize OCD as a common, treatable form of major mental disorder.
After the pioneering epidemiological catchment area (ECA) studies carried out by the National Institute of Mental Health in the early 1980s reported that the prevalence of OCD was substantially higher than expected, (Robins, Holzer, & Weissman, 1984) repeated population studies using similar methods have demonstrated a lifetime prevalence of 2-3% worldwide (Weissman, Bland & Canino, 1994). Taiwan and India were the only exceptions, with rates below 1%. If these estimates are accurate, then OCD affects more than 50 million people in the world today. The prevalence does not appear to be influenced by socioeconomic status, educational achievement, or ethnicity. The disorder is more common than schizophrenia, and about half as common as depression. Yet the illness remains largely under-recognized, and the psychosocial and economic costs to society from untreated OCD are high (Hollander, & Wong, 1998). It is not surprising that the World Health Organization has now recognized OCD as a public health priority.
While there is little doubt that the ‘hidden epidemic’ of OCD exists, the actual prevalence of clinically relevant disorder has been called into question. In the ECA studies lay interviewers were trained to make DSM-III diagnoses using the Diagnostic Interview Schedule (DIS). However, clinical reappraisal of DIS-positive cases resulted in less than 25% continuing to meet the criteria for OCD (Nelson & Rice, 1997).One explanation is that the rates of illness reported in the original ECA studies may have been exaggerated. Alternatively, the findings may reflect variability in the severity of the disorder over time.
Obsessive compulsive disorder is more common in women, although the differences are not as obvious as in depression or other anxiety disorders. An average female to male ratio of 1.5:1.0 is accepted for the community at large, although the ratio appears roughly equal in the adolescent population, reflecting perhaps the earlier onset in boys. In particularly in males, having obsessions and compulsions or magical thinking, poor social adjustment, and an early chronic course, predicted a worse outcome.
A more recent 5-year prospective follow-up study of 100 OCD patients showed that in spite of the introduction of modern treatments, outcomes were similar to Skoog and Skoog’s cohort, with only 20% reaching full remission of their OCD, 50% showing partial remission, and the remainder unchanged or worse over 5 years. Less severe illness and being married were associated with a better outcome (Steketee Eisen & Dyck, 1999).
Most patients suffer a mixture of different obsessions or compulsions. Surveys have consistently identified contamination fears as the most common obsession, with concern about harm to others, pathological doubt, somatic obsessions and the need for symmetry also occurring frequently. Half of all OCD patients admitted for treatment suffer compulsions in the realm of repetitive checking or excessive cleaning and washing. 20 Key themes have been identified that underlie most symptoms. These include abnormal risk assessment, pathological doubt and incompleteness.
Patients with OCD usually retain full insight into the absurdity of their symptoms, although this is not always the case (Insel & Akiskal, 1986). The DSM-IV singles out patients with poor insight as a meaningful subgroup. These individuals have more complex symptomatology, which makes diagnosis more difficult, and tend to be more severely ill. They have only a limited sense of the excessiveness and irrationality of their thoughts and behaviours and are therefore difficult to engage in treatment. They may appear to be deluded (and hence receive inappropriate treatment) but longitudinal studies show they do not go on to develop schizophrenia-like illnesses. In a cohort of 475 patients with OCD, (6%) displayed lack of insight.
Mild forms of obsessional behaviour, such as repetitive checking or superstitious behaviour commonly occur in everyday life. They only meet the criteria for OCD if they are time-consuming, or associated with impairment or distress.
Recurrent, intrusive thoughts, impulses and images also occur in other mental disorders thought to share a relationship with OCD: for example, the preoccupation with bodily appearance, in body dysmorphic disorder; with a feared object, in specific phobia; with illness, in hypochondriasis; or with hair-pulling, in trichotillomania. A diagnosis of OCD should only be contrast; men predominate in surveys of OCD referrals, possibly reflecting a greater severity in males.
Women during pregnancy and the puerperium are particularly at risk of developing the disorder. In a study by Neziroglu et al of 59 mothers with OCD, experienced their symptoms for the first time during pregnancy. In many cases, pre-existing obsessional tendencies are unmasked and exaggerated by the events surrounding childbirth.
Obsessive compulsive disorder is considered to be one of the most strongly inherited mental disorders (Pauls, Alsobrook, & Goodman, 1995). Approximately one-fifth of nuclear family members of OCD sufferers show signs of OCD, and the younger the sufferer the more likely they are to have a first-degree relative affected. The clustering of OCD and Tourette’s syndrome (TS) within families suggests a common inherited factor.
The course of the illness can vary from a relatively benign form in which the patient experiences infrequent, discrete episodes of illness interspersed with symptom-free periods, to malignant OCD, characterized by unremitting symptoms and substantial social impairment.
In a 40-year prospective follow-up study, reported by Skoog and Skoog, the authors managed to locate and examine 144 out of 251 OCD patients who had previously been admitted as inpatients under their care between 1947 and 1953. 1Given that effective treatments for OCD were not developed until the end of the study, much of the data is naturalistic. The authors found that roughly 60% showed signs of general improvement within 10 years of onset of illness, rising to 80% by the end of the study.
However, only 20% achieved full remission even after nearly 50 years of illness; 60% continued to experience significant symptoms; 10% showed no improvement whatsoever; and another 10% had worsened. In 60% of cases the content of the obsessions shifted markedly over the follow-up period (Pauls, Alsobrook, & Goodman, 1995).
One-fifth of those who had shown an early, sustained improvement subsequently relapsed, even after 20 years without symptoms, suggesting early recovery does not rule out the possibility of very late relapse. Intermittent, episodic disease was common during the early stage of illness, and predicted a more favourable outcome, whereas chronic illness predominated in the later years.
Early age of onset, made if there are also unrelated obsessive-compulsive symptoms, in which case more than one diagnosis may be warranted. Activities such as preoccupation with eating, sex, shopping and gambling are not considered genuine compulsions because they are not egodystonic, and the individual usually only tries to resist because of the adverse consequences.
Hollander E, Wong C, 1998). Psychosocial functions and economic costs of obsessive compulsive disorder, CNS Spectrums (3 (5) suppl. 1:48-58.
Insel T, Akiskal H, 1986. Obsessive compulsive disorder with psychotic features: a phenomenological analysis, Am J Psychiatry 143:1527-33.
Nelson E, Rice J, 1997. Stability of diagnosis of obsessive-compulsive disorder in the Epidemiological Catchment Area Study. Am J Psychiatry 154:826-31.
Pauls DL, Alsobrook JP, Goodman W et al, 1995). A family study of obsessive compulsive disorder, Am J Psychiatry 152 : 76-84.
Robins LN, Holzer JE, Weissman MM et al, 1984 Lifetime prevalence of specific psychiatric disorders in three sites, Arch Gen Psychiatry (1984) 41 :949-58.
Steketee G, Eisen J, Dyck I et al, (1999) Predictors of course in obsessive compulsive disorder, Psychiatr Res 89 (3):229-38.
Weissman MM, Bland RC, Canino GL et al, 1994. The cross national epidemiology of obsessive-compulsive disorder, J Clin Psychiatry 55 :5-10.