During a single interview, a patient cycles rapidly between tearfulness, sudden laughter, and irritability within a few minutes, with no clear external event prompting each shift and the changes appearing far more abrupt and pronounced than anything discussed would warrant. Before revealing the answer: is this reactivity of mood?
No, this is more consistent with lability of affect than reactivity of mood. The shifts here are abrupt and disproportionate to any identifiable trigger, cycling through markedly different emotional states within minutes, which is the defining pattern of lability of affect rather than a mood tracking genuine external circumstances, which is characteristic of reactivity of mood.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 6, 'Disorders of Emotion'.