What is the term for a repetitive and rigid behavior or mental act that a person feels driven to perform?

The term for a repetitive and rigid behavior or mental act that a person feels driven to perform is known as a compulsion. Compulsions are typically associated with obsessive-compulsive disorder (OCD) and are actions that an individual feels they must carry out, often in response to intrusive thoughts or obsessions. These behaviors are performed to alleviate distress or prevent a feared event, although the actions are often not connected to the feared situation in a realistic way.

In contrast, dissociative identity disorder involves a disruption of identity characterized by two or more distinct personality states, while dissociative amnesia entails an inability to recall important autobiographical information, typically following a stressful or traumatic event. Conversion disorder involves neurological symptoms that cannot be explained by medical conditions, often related to psychological distress. These terms highlight different psychological phenomena that do not involve the compulsive behaviors described in the question.