A patient reports difficulty remembering a period of her life. Before revealing the answer, decide how you would explore this.

Establish the pattern of the loss precisely, since this is itself diagnostically informative: is it sudden or gradual in onset, circumscribed to a specific period or category, or more diffuse, and is personal identity affected or spared? Ask whether the gap affects the ability to form new memories going forward, retrieve memories from before the affected period, or both, since this distinction points toward different underlying mechanisms. Consider and, where relevant, actively exclude psychological causes, physical brain disturbance, and ordinary processes such as decay or interference before concluding the gap is pathological, and note whether the patient offers any confident but potentially inaccurate account of the missing period, which would instead suggest paramnesia.