Which symptom is NOT included in the diagnostic criteria for Generalized Anxiety Disorder?

Generalized Anxiety Disorder (GAD) is characterized by persistent and excessive worry about various aspects of life, which includes several specific symptoms recognized in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The core symptoms used to diagnose GAD encompass difficulty concentrating, sleep disturbances, and restlessness.

Difficulty concentrating refers to the individual's struggles to focus due to their persistent worries, which can impair various aspects of functioning. Sleep disturbances often manifest as difficulty falling asleep, staying asleep, or experiencing restless sleep, as anxiety can lead to overactive thoughts that hinder restful sleep. Restlessness is another common symptom, where individuals may feel easily fatigued by their constant anxiety and experience an ongoing sense of being on edge.

Behavioral rigidity, however, does not fit within the criteria for diagnosing GAD. While rigidity in behavior can be observed in various other conditions, such as obsessive-compulsive disorder (OCD) or certain personality disorders, it is not a specific symptom of anxiety defined in the context of GAD. Thus, its absence from the diagnostic criteria makes it the correct choice in this scenario.