In summary, obsessions are repetitive and persistent thoughts (e.g., of contamination with germs), images (e.g., of violent or horrific scenes), or urges (e.g., to stab someone). The specific content of obsessions and compulsions varies between individuals. However, certain themes, or dimensions, are common, including those of cleaning & contamination; symmetry (symmetry obsessions and repeating, ordering, and counting compulsions); forbidden or taboo thoughts (e.g., aggressive, sexual, or religious obsessions and related compulsions); and harm (e.g., fears of harm to oneself or others and checking compulsions).
Individuals with obsessions typically attempt to behave in a way to compensate for these thoughts by performing mental acts (e.g., counting, repeating words silently) or ritual behaviors called compulsions (e.g., washing, checking). However, performing compulsive acts are often not effective and fail to neutralize the obsessions; instead, this leads to the exacerbation of such thoughts and to ultimately, greater distress. One example of a compulsion performed in response to an obsession is where an individual who has extreme thoughts of contamination attempts to repetitively/ritually wash their hands in a fashion that feels “just right” (e.g., 10 times). Though their aim is to reduce the distress triggered by obsessions or to prevent a feared event (e.g., becoming ill), the original obsession and compulsion are not connected in a realistic way to the feared event and are clearly excessive (e.g., showering for hours each day). Compulsions are not done for pleasure, although some individuals experience temporary relief from their anxiety.
Moreover, many individuals with obsessive-compulsive disorder (OCD) have dysfunctional beliefs. These beliefs can include an inflated sense of responsibility and the tendency to overestimate threat; perfectionism; and over-importance of thoughts (e.g., believing that having a forbidden thought is as bad as acting on it); and the need to control thoughts. Despite the fact that these beliefs may appear consistent with the person’s general personality, the key requirement for meeting for OCD is that the obsessions in OCD are not perceived as pleasurable or experienced as voluntary. In fact a hallmark symptom of obsessions is that they are intrusive and unwanted.
Individuals with OCD vary in the degree of insight they have about the accuracy of the beliefs that underlie their obsessive-compulsive symptoms. Many individuals have good or fair insight (e.g., the individual believes that the house definitely will not, probably will not, or may or may not burn down if the stove is not checked 30 times). Some have poor insight (e.g., the individual believes that the house will probably burn down if the stove is not checked 30 times), and a few (4% or less) have absent insight/delusional beliefs (e.g., the individual is convinced that the house will burn down if the stove is not checked 30 times). Insight can vary within an individual over the course of the illness. Poorer insight has been linked to worse long-term outcome.
This criteria has been updated for DSM-5; diagnostic code: 300.3.