Which psychological symptom may occur in hyperthyroidism?

• A. Decreased attention span
• B. Irritability
• C. Restlessness
• D. Emotional lability

Answer: (C)

Hyperthyroidism speeds up brain and nervous system activity, increasing overall arousal and sympathetic drive. That heightened neural tone often presents as restlessness—an inner sense of agitation and the need to move or pace—which is a classic mental-state change in this condition. Among the options, restlessness best captures this characteristic neuropsychiatric effect of excess thyroid hormone.

Irritability and emotional lability can occur because of increased nervous system excitability, but they’re less specific to the hyperthyroid state. A decreased attention span may happen, but it’s not as defining a feature as the pervasive restlessness produced by the hyperadrenergic milieu.