Which of the following behaviors indicates a symptom of OCD?

The behavior of urgently needing to clean their living space repeatedly is a classic symptom of Obsessive-Compulsive Disorder (OCD). Individuals with OCD often experience obsessive thoughts that create significant anxiety or distress, leading them to perform compulsive behaviors as a way to alleviate that anxiety. In this case, the repeated cleaning is a compulsive act that may be driven by fears of dirtiness, contamination, or the need for order. This pattern of behavior is central to the diagnosis of OCD, as it reflects the cycle of obsessions and compulsions characteristic of the disorder.

Other behaviors mentioned do not align with the hallmark features of OCD. Difficulty in establishing relationships can stem from various factors but is not specific to OCD. Generalized excessive worrying about life events is more indicative of Generalized Anxiety Disorder (GAD), while infrequent feelings of sadness typically relate to mood disorders rather than the compulsive behavior seen in OCD. Hence, the urgency and repetition involved in the cleaning behavior directly connect with the defining aspects of OCD.