What is the primary symptom of obsessive-compulsive disorder (OCD)?

The primary symptom of obsessive-compulsive disorder (OCD) is characterized by the presence of obsessions and compulsions. Obsessions are persistent and intrusive thoughts, images, or urges that cause significant anxiety or distress. Compulsions are repetitive behaviors or mental acts that a person feels driven to perform in response to the obsessions or according to rigid rules. These compulsions are often intended to reduce the anxiety generated by the obsessions or prevent a feared event or situation. This duality of experiencing both obsessions and related compulsions is what fundamentally distinguishes OCD.

Focusing specifically on the other options, while some individuals with OCD may have an obsession with cleanliness, this represents only one potential manifestation of the disorder. The disorder itself encompasses a broader range of obsessions and compulsions, not strictly limited to cleanliness. Excessive physical activity and intense sadness are not characteristic symptoms of OCD; rather, they may relate to different mental health conditions such as anxiety disorders or depression. Therefore, the defining feature of OCD is indeed the combination of obsessions and compulsions.