Which of the following is a core symptom of Obsessive-Compulsive Disorder?

Recurrent and intrusive thoughts, also known as obsessions, are indeed a core symptom of Obsessive-Compulsive Disorder (OCD). These thoughts are often unwanted and cause significant anxiety or distress to the individual. They can manifest in various forms, such as fears of contamination, fears of harming oneself or others, or doubts about safety or completeness. The nature of these obsessions can lead individuals to feel compelled to engage in compulsive behavior as a way to try to alleviate the anxiety caused by these intrusive thoughts.

While the presence of compulsive behaviors is often associated with OCD, they are actually considered a response to the obsessions rather than a core symptom on their own. Therefore, focusing on the intrusive thoughts captures a fundamental characteristic of the disorder.

Significant improvement in daily functioning does not characterize OCD; rather, individuals often experience a deterioration in their daily lives due to the distress caused by their obsessions and compulsions. Lastly, the inability to recall specific memories is not related to OCD and is more indicative of other conditions, such as dissociative disorders or certain types of amnesia.

Thus, understanding the role of recurrent and intrusive thoughts clarifies why this symptom is pivotal in diagnosing and treating OCD.