Delirium superimposed on dementia Concept, characteristics and care

Delirium as a severe, acute neuropsychiatric syndrome is common in older persons. The high prevalence of delirium superimposed on dementia (DSD) can be explained by the fact that increasing age, cognitive impairment and dementia are all important risk factors for delirium. DSD is associated with poor outcomes, such as accelerated cognitive and functional decline, and increased mortality. Behavioral disturbances in DSD are common and associated with immediate, intense suffering in patients and with distress in families and professional caregivers. At the psychogeriatric unit of the Parnassia Group, a large organization for mental health care in the Netherlands, patients are admitted who suffer from cognitive disorders with severe behavioral and other neuropsychiatric problems. In about 70% of these psychogeriatric patients, delirium is the cause of the severe behavioral problems. That DSD often goes unrecognized is reflected by the fact that in up to 80% of these patients delirium was undiagnosed on referral to the department.
The general aim of this thesis is to explore the phenomenon DSD from conceptual, practical and clinical points of view and to emphasize the existence of delirium as a severe complication in dementia. The research approach is fourfold with the goals to (1) increase our knowledge about the conceptual boundaries between dementia and delirium, (2) describe clinical observations relevant to the diagnosis and clinical care in DSD, (3) explore influencing factors on diagnostic and medical conditions in DSD and finally (4) explore the neuropathological substrates of DSD.
The present thesis is the first of its kind to study extensively the clinical problem of DSD, in psychogeriatric patients, in the setting of a general psychiatric hospital.