Delirium in acute stroke is associated with increased cognitive and psychiatric symptoms over time: The Nor-COAST study

•Delirium in acute stroke may increase risk of cognitive and psychiatric symptoms.•Mixed-model linear regression was used to compare patient groups.•Within the first year, the groups were fairly similar.•Later in the course, the groups were significantly different.•Patients with acute delirium had more symptoms of anxiety and depression.•Scores on cognitive tests were also significantly lower in these patients. Delirium, an acute and fluctuating mental disturbance of attention, cognition, and consciousness, commonly occurs in acute stroke. Research on long-term outcomes of stroke patients experiencing delirium is limited, especially regarding cognitive and psychiatric symptoms. As part of the Nor-COAST study, 373 patients were screened for delirium using the Confusion Assessment Method (CAM) in the acute phase of stroke. Patients were included in the mixed-model linear regression analyses if they had available data from the follow-ups at three, 18 or 36 months, totaling 334 (44.6 % women, mean (SD) age: 72.1 (12.5) years, 17 (5.1 %) diagnosed with delirium). Global cognition was measured using the Montreal Cognitive Assessment (MoCA). Psychiatric symptoms were measured using the Hospital Anxiety and Depression Scale (HADS) and the Neuropsychiatric Inventory-Questionnaire (NPI-Q). At three months, delirium was associated with a higher NPI-Q score (Mean (SD) 2.9 (3.6) vs 1.4 (2.2)). At 18 and 36 months, delirium was associated with a lower MoCA score (Mean (SD) 19.7 (6.6) vs 24.3 (5.0), and 20.6 (7.6) vs 24.6 (4.8)), higher HADS anxiety symptoms (5.0 (4.3) vs 3.3 (3.3), and 5.9 (4.1) vs 3.4 (3.6)), higher HADS depression symptoms (7.2 (4.7) vs 3.4 (3.3), and 6.6 (5.1) vs 3.7 (3.7)), and higher NPI-Q score (2.4 (4.4) vs 1.7 (2.3), 2.6 (4.5) vs 1.0 (1.9)). Delirium significantly predicted the psychiatric symptoms hallucinations and agitation. Patients with delirium in the acute phase of stroke may be particularly vulnerable to developing cognitive and psychiatric symptoms in the chronic phase.