A patient's family reports that he has become unusually short-tempered. Before revealing the answer, decide how you would explore whether this is irritability.

Ask about the persistence of the change and whether it represents a genuine shift from the patient's usual, baseline temperament, rather than a single isolated instance of being in a bad mood. Ask for specific examples of minor, everyday provocations that have triggered a disproportionately strong response, since this lowered threshold across a range of situations is the core feature. Establish that this is not specific to depressive illness or to elevated mood, since irritability can be a useful clue prompting a broader assessment of underlying mood state in either direction, and screen carefully for any accompanying loss of control over the emotional display itself, which would instead point toward affective incontinence.