What is the primary characteristic of obsessive-compulsive disorder?

The primary characteristic of obsessive-compulsive disorder (OCD) is defined by the presence of intrusive thoughts, known as obsessions, which lead to repetitive behaviors, or compulsions. Individuals with OCD experience unwanted, distressing thoughts that cause significant anxiety or discomfort. To alleviate this anxiety, they engage in specific behaviors or mental acts, which are intended to prevent a feared event or situation from occurring. These compulsions can take the form of rituals that the person feels driven to perform, even when they realize that the actions are excessive or irrational.

The other options represent symptoms or characteristics associated with different mental health disorders. For instance, hallucinations are typically associated with disorders like schizophrenia, while avoidance of social situations is a key feature of social anxiety disorder. Severe mood swings are characteristic of mood disorders, such as bipolar disorder. Each of these conditions presents distinct symptoms that differ from the core characteristics of OCD, which is specifically identified by the cycle of obsessions and compulsions.