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Course and Prevalence of Obsessive-Compulsive Disorder (OCD)


About 1.6% of the general population - or over one in every hundred individuals - suffer from OCD [ref], which is a prevalence that has been found to be similar in various countries [ref]. According to the World Health Organization, OCD is considered to be among the top 10 illnesses in the world that cause the greatest amount of disability over the course of a lifetime [ref]. OCD seems to affect men and women equally often, but early-onset OCD (beginning in childhood and early adolescence) is more common among males [ref].


OCD typically starts in late adolescence or in the early 20's, with a quarter of all cases, if not more, beginning in childhood or early adolescence [ref]. In about half of all cases the symptoms of OCD can persist for many years even with treatment [ref, ref]. This is more likely if the condition begins earlier in life, if the individual requires in-hospital treatment for their OCD, or if the individual suffers from other psychiatric conditions as well [ref]. Having poor insight also predicts a more severe course of OCD that is more difficult to treat [ref].

Early-onset OCD also tends to involve more severe symptoms, higher rates of compulsions without obsessions, and a very higher rate (up to 90%) of co-occuring disorders, including Tic Disorder, ADHD, Depression and Anxiety Disorders [ref]. In adults with OCD, probably around half of all individuals suffer from other co-occuring Anxiety Disorders or from Major Depression [ref, ref, ref].

OCD Spectrum

There are some experts who argue that OCD is in fact part of a wider spectrum of disorders, called the OCD Spectrum, which may include Tic Disorder, Body Dysmorphic Disorder, Hypochondriasis, Pathological Grooming Disorders like Trichotillomania, and possibly Eating Disorders [ref, ref]. All of these conditions share the tendency for having certain compulsive behaviors or obsessive worries. Individuals with OCD, as well as their family members, are more prone to having these OCD Spectrum disorders than people in the general population [ref], and these disorders likely share some common underlying causes [ref].

Types of Obsessions and Compulsions

Individuals with OCD can differ considerably in the kind of obsessions and compulsions that characterize their conditions. Studies have found that most people with OCD tend to fall into one of four symptom groups [ref]:

Symmetry: includes obsessions that various objects in one's surroundings should be positioned symmetrically or placed in a particular order, and compulsions of ordering objects, repeating specific actions or mental acts in a stereotypical and ritualistic fashion, and counting things, often to see if they occur in specific multiples.

Forbidden thoughts: includes taboo and distressing thoughts, images or impulses of an aggresive or sexual nature, and religious preoccupations of having sinned, being guilty or expecting divine punishment. Checking compulsions, such as repeatedly checking that doors are locked or stoves are turned off, also occur in this group, though such compulsions can be found in other groups too.

Cleanliness/contamination: includes obsessions of being contaminated by germs or other forms of dirt and impurity, usually after having come into contact with certain sources of germs such as door knobs, bathrooms, or shaking peoples' hands. Cleaning compulsions are common in this group, and can include a tendency to wash one's hands, body or home repeatedly and excessively.

Hoarding and collecting: includes a tendency to feel that objects cannot be discarded, and will result in individuals hoarding excessive amounts of certain objects. Many times the objects that are collected and stored are of questionnable value, such as old newspapers or even bags of garbage. In extreme cases, individuals' homes can become completely filled with these objects to the point where there is barely any room for people to walk.



Overview of Treatments