You are assessing a patient with known depressive illness and want to establish whether psychomotor retardation is present. Which single question or approach would most efficiently confirm it at interview?

Psychomotor retardation is best confirmed by combining what you observe directly during the interview (delayed responses, slowed and quiet speech, reduced spontaneous movement) with what the patient reports subjectively about their own sense of being slowed down. Asking about interest or motivation alone risks conflating this with apathy, a related but distinct phenomenon that concerns reduced interest and motivation rather than a generalised physical and cognitive slowing.

Key discriminating feature: Psychomotor retardation has both an observable component (response latency, slowed movement and speech, best assessed by direct observation during the interview) and a subjective component (the patient's own sense of being physically weighed down), so the most efficient single approach combines a direct subjective question with an objective observation made during the same interview.

Common misconception: Asking only about interest or motivation risks eliciting apathy instead, which is a related but distinct phenomenon — psychomotor retardation is specifically about the pace of movement, speech, and thought, not the level of interest in activities.

Clinical interviewing principle: Combine direct observation (timing response latency, noting the pace of movement and speech) with a specific subjective question, rather than relying on either alone — this mirrors how the phenomenon's own eliciting notes describe assessing it at the bedside.