What defines obsessive-compulsive disorder (OCD)?

Obsessive-compulsive disorder (OCD) is characterized primarily by the presence of intrusive thoughts, known as obsessions, which cause significant anxiety for the individual. In response to these distressing thoughts, a person with OCD often engages in compulsive behaviors—ritualistic actions performed in an attempt to alleviate the anxiety or prevent a feared event from occurring. This cycle of obsessions and compulsions forms the hallmark of OCD, leading individuals to feel driven to perform these behaviors, even when they recognize that they are excessive or irrational.

The other options describe different mental health conditions or responses. Hallucinations and delusions relate to disorders like schizophrenia. Persistent sadness and loss of interest pertain to depression. Heightened responsiveness to stressful stimuli can be associated with conditions like post-traumatic stress disorder (PTSD). Each of these is distinct and does not encapsulate the criteria for diagnosing OCD, which revolves specifically around the interplay of obsessions and compulsions.