A patient performs an unusual repetitive movement. Before revealing the answer, decide what distinguishes occupational delirium from a mannerism.

Ask about the broader clinical context in which the movement occurs. Occupational delirium differs from a stereotypy or mannerism, which are primarily psychiatric motor signs, by its specific occurrence within an acute, organically driven dream-like change of consciousness, and by its recognisable connection to the patient's actual occupation: the movements are specifically the practised actions of the person's real trade, occurring alongside disorientation and confusion. A mannerism, by contrast, is an unusual, stilted way of carrying out an ordinary, goal-directed movement, occurring in psychiatric and neurological conditions, and even in people without any mental illness, with no requirement for an underlying disturbance of consciousness or connection to occupation. Whether the movement occurs specifically within an acute, organic disturbance of consciousness and reflects the person's actual trade, rather than simply being an odd, individual style of movement, is the key distinguishing feature.