Psychiatric Complications of Dementia

Article excerpt

Our paper describes the neuropsychiatric signs and symptoms of late-life disorders of cognitive impairment. Late-life cognitive disorders are associated with psychiatric symptoms in various ways-from apparent risk factors to pathognomonic features of particular dementias. They contribute greatly to the burden of illness, both in people with dementia, and in those who care for them. Here we consider specific dementia symptoms in relation to dementing illnesses and to the stages of dementia. Recognizing that no one drug is likely to successfully treat all dementia symptoms, we argue for a syndromic approach, which can lead to appropriately targeted therapy.

Can J Psychiatry. 2011;56(7):398-407.

Key Words: neuropsychiatric symptoms, dementia, Alzheimer disease, dementia with Lewy bodies

Abbreviations

ACCORD A Canadian Cohort Study of Cognitive Impairment and Dementia

AD Alzheimer dementia

ADL activities of daily living

BEHAVE-AD Behavioral Pathology in Alzheimer's Disease Scale

CAMI Cohen-Mansfield Agitation Inventory

CIND cognitive impairment, no dementia

DLB dementia with Lewy bodies

FTD frontotemporal dementia

MCI mild cognitive impairment

NPI Neuropsychiatrie Inventory

NPS neuropsychiatrie syndrome

RBD REM behaviour disorder

REM rapid eye movement

VaD vascular dementia

Psychiatric symptoms in later life share a complex relation with dementia. They can be prodromal symptoms, or frequently co-occur with dementia, where they can define dementia subtypes. Psychiatric symptoms vary in type and intensity through the course of dementia, are associated with excess disability and worse quality of life, and morbidity in sufferers can lead to significant burden and psychiatric disorders in caregivers, and can lead treating physicians to therapeutic desperation.

After discussing how dementias are conceptualized, we discuss the various psychiatric complications associated with dementias. We will offer only a few comments on the treatment of neuropsychiatrie signs and symptoms, noting that there are more drugs used in practice than is supported by evidence for their use. We will also suggest that the notion that one drug should improve all psychiatric symptoms in a patient with dementia, though evidently unrealistic, appears to have been the model of treatment of many clinical trials. We note that nonpharmacological treatments, though perhaps less widely used formally, also suffer from this deficiency in the evidence base.' Finally, we will note that some aspects of the treatment of people with dementia who live at home with others must also consider the impact on the suffering of caregivers. We will argue for scholarly inquiry into individual symptoms, how they arise, how they progress, how much they trouble patients and caregivers, and how likely they are to respond to treatment.

Psychiatric complications of dementia are commonly referred to as behavioural and psychological symptoms of dementia, a loosely organized concept that incorporates various psychiatric symptoms in dementia. This is part of a syndromic approach to several psychiatric syndromes,2 which is advancing to include diagnostic criteria in AD.3-6 While syndromic approaches can improve diagnostic agreement, especially when used with a structured interview, they are especially valued for allowing etiological identification.2 Even so, the history of psychiatric research shows that validating psychiatric syndromes is difficult.7 For a syndrome to be valid, it should meet 1 of 2 criteria; it needs to

be demonstrated to be an entity, separated from neighboring syndromes and normality by a zone of rarity. Alternatively, if the category's defining characteristics is more fundamental - that is, if the category is defined by a physiological, anatomical, histological, chromosomal, or molecular abnormality - clear, qualitative differences must exist between these defining characteristics and those of other conditions with a similar syndrome. …