MedGen

Obsessive-compulsive disorder (OCD) is characterized by recurring obsessions and/or compulsions and has been estimated to affect nearly 5 million people in the United States (Karno et al., 1988). Evidence for a strong genetic component in OCD comes from twin studies, family genetics studies, and segregation analyses, as reviewed by Alsobrook et al. (2002). Zhang et al. (2002) suggested that hoarding is likely to be an evolutionarily conserved trait that, in times of adversity, was associated with increased survival and reproductive fitness. However, extreme forms of this trait are associated with marked disability and poor response to treatment (Black et al., 1998; Mataix-Cols et al., 1999). [from OMIM]

Behavior that consists of repetitive acts, characterized by the feeling that one "has to" perform them, while being aware that these acts are not in line with one's overall goal. [from HPO]

A category of psychiatric disorders which are characterized by anxious feelings or fear often accompanied by physical symptoms associated with anxiety. [from NCI]