ADHD or anxiety: how do you tell what's driving the constant restlessness?

Restlessness can show up in both ADHD and anxiety, but clinicians try to understand why the restlessness is happening and what it is linked to. While it can feel similar from the inside, the drivers are often different, and careful history-taking usually clarifies this over time. In ADHD, restlessness tends to be longstanding and situational. It often starts in childhood and is most noticeable during tasks that require sustained attention, sitting still, or mental effort. The internal experience is usually one of boredom, under-stimulation, or a need to move in order to focus. Thoughts may jump quickly between topics, but they are not necessarily threat-based or worry-focused. Movement can feel regulating rather than distressing. In anxiety, restlessness is more closely tied to physiological arousal and worry. The body feels keyed-up, tense, or on edge, often accompanied by racing thoughts about potential problems, “what if” scenarios, or a sense that something bad might happen. The restlessness is typically driven by fear or anticipation rather than boredom, and it may persist even when a person wants to relax. Clinicians look at the timing, triggers, thought content, and emotional tone of the restlessness, as well as associated symptoms such as sleep disturbance, avoidance, or physical anxiety symptoms. Importantly, this is not always an either/or decision. People can have both ADHD and anxiety, and distinguishing their relative contributions may require repeated assessments over time, observation of response to treatment, and psychological formulation rather than a single appointment.