When a person experiences symptoms that are suspected to be a possible dementia, they may be referred for specialist memory assessment. However, in the initial diagnostic stages, delirium and depression are differential diagnoses that require consideration, with attention paid to ruling these out as they can mimic the presentation of dementia. Similarly, delirium and depression can be superimposed on a person who already has an existing diagnosis of dementia. In both instances, this can be distressing and debilitating  and requires community nurses to be able to differentiate between the conditions and to take appropriate measures to enable rapid identification and assessment and, when required, onward referral for treatment and management. The differentiating signs and symptoms of the three conditions can vary in their subtlety and similarity and require vigilance to identify in a timely manner. Community nurses have a significant role to play in the screening, identification, assessment and management of patients with dementia, delirium and depression. This paper is the fifth in a series that follows two patient stories in their experiences of dementia.