<Tr> <Th> Frequency </Th> <Td> 2.3% </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> Obsessive--compulsive disorder (OCD) is a mental disorder where people feel the need to check things repeatedly, perform certain routines repeatedly (called "rituals"), or have certain thoughts repeatedly . People are unable to control either the thoughts or the activities for more than a short period of time . Common activities include hand washing, counting of things, and checking to see if a door is locked . Some may have difficulty throwing things out . These activities occur to such a degree that the person's daily life is negatively affected . Often they take up more than an hour a day . Most adults realize that the behaviors do not make sense . The condition is associated with tics, anxiety disorder, and an increased risk of suicide . </P> <P> The cause is unknown . There appear to be some genetic components with both identical twins more often affected than both non-identical twins . Risk factors include a history of child abuse or other stress inducing event . Some cases have been documented to occur following infections . The diagnosis is based on the symptoms and requires ruling out other drug related or medical causes . Rating scales such as the Yale--Brown Obsessive Compulsive Scale can be used to assess the severity . Other disorders with similar symptoms include anxiety disorder, major depressive disorder, eating disorders, tic disorders, and obsessive--compulsive personality disorder . </P>

When was ocd first added to the dsm