Free Online Book from PSYPLEXUS - a portal for mental health professionals

Organic mental disorders


Home References



Dementia is a syndrome of impaired cognition caused by brain dysfunction. It has been defined as “the development of multiple cognitive deficits that include memory impairment and at least one of the following: aphasia, apraxia, agnosia, or a disturbance in executive functioning” (American Psychiatric Association, 1994). Dementia has become a major public health concern because it leads to serious physical, functional, and psychologic morbidity for the individual (Burns et al., 1991; Lyketsos and Rabins, 1994), because it shortens life expectancy (Kelman et al., 1994; Kukull et al., 1994), and because caring for people with dementia exacts a heavy toll on the care providers over the course of the illness (George and Gwyther, 1986; Drinka et al., 1987).


Most studies in the developed countries have reported the overall prevalence of dementia to be between 5% and 10% of the elderly (Canadian Study of Health and Aging Working Group, 1994; Evans et al., 1989). In a largely illiterate rural population in northern India, Chandra et al. (1998) found an overall prevalence rate of 0.84% and 1.36% for all dementias; and 0.62% and 1.07% for Alzheimer’s Disease (AD) in population aged > 55 years and > 65 years respectively. Neither gender nor literacy was associated with the prevalence. These appear to be the lowest prevalence of dementia reported from anywhere in the world. Universally, the single largest subcategory of dementia is AD, with estimated size of 50% -90% of all dementias (Kukull and Ganguly, 2000).

Clinical features

Memory impairment is generally a prominent early symptom of dementia. Individuals with dementia have difficulty learning new material. In more severe dementia, individuals also forget previously learned material, including the names of loved ones. Individuals with dementia may have difficulty with spatial tasks, such as navigating around the house or in the immediate neighborhood. Poor judgment and poor insight are also common. In order to make a diagnosis of dementia, these cognitive deficits must be sufficiently severe to cause impairment in occupational or social functioning and must represent a decline from a previous level of functioning. The order of onset and relative prominence of the cognitive disturbances and associated symptoms vary with the specific type of dementia.

Other symptoms of dementia include disinhibited behavior, including making inappropriate jokes, neglecting personal hygiene, exhibiting undue familiarity with strangers, or disregarding conventional rules of social conduct. Suicidal behavior may occur in mildly impaired individuals, who are more likely to have insight into their deficits. Anxiety is fairly common, and some patients manifest "catastrophic reactions," overwhelming emotional responses to relatively minor stressors such as changes in routine or environment. Depressed mood and sleep disturbances are common. Delusions of persecution and misidentification, and hallucinations, most commonly in the visual modality, could be present. Some patients exhibit sundowning, a peak period of agitation during the evening hours. Dementia is sometimes accompanied by motor disturbances, which may include gait difficulties, slurred speech, and a variety of abnormal movements. Other neurological symptoms, such as myoclonus and seizures, may also occur (American Psychiatric Association, 1997).


The assessment of a patient presenting with symptoms of dementia should address the patient's medical condition, including functional status, cognitive status, other medical conditions, behavioral problems, psychotic symptoms, and depression. The assessment should also address the patient's support system, identify the primary caregiver and assess the patient's decision-making capacity.

Assessment of Daily Function

Careful and competent functional assessment identifies how to maximize patient autonomy (Kane, et al., 1994). Functional assessment includes physical, psychological and socioeconomic domains. Standardized assessment instruments can provide information on the patient's capacity for self care and independent living. Physical functioning is measured along a continuum and may focus on basic Activities of Daily Living (ADL's) that include feeding, bathing, dressing, mobility and toileting (Kane, et al., 1994; Katz, 1983). In addition, Instrumental (or intermediate) Activities of Daily Living (IADL's) assess more advanced self care activities, such as shopping, cooking, and managing finances and medications. A useful informant-based tool to assess dimensions of function is the Functional Activities Questionnaire (Pfeffer et al., 1982).

Cognitive changes commonly associated with AD often impact both the instrumental and eventually the basic activities of daily living (Fitz and Teri, 1994; Small, et al., 1997). A baseline assessment of functional abilities is important to determine a standard to which future functional deficits can be compared. It will also provide realistic treatment planning information and allow early supportive interventions to be initiated (Ham, 1997). Assessment of a patient's living environment can identify environmental supports that may be needed to maximize function, ensure safety, and minimize caregiver stress.

Assessment of Cognitive Status

The cognitive status of the patient should be assessed and documented using a valid and reliable instrument, such as the Mini-Mental Status Examination (MMSE) (Folstein et al., 1975). The MMSE can also be a useful predictor of ADL and IADL impairment in patients diagnosed with dementia (Ford et al., 1996). The MMSE is sensitive to formal education level and primary language of the patient (Crum et al., 1993; Taussig et al., 1996; Small et al., 1997). Valid bedside executive instruments, such as the Executive Interview and an executive clock-drawing task, are better than MMSE in detecting executive impairment (Royall et al., 1992; Royall et al., 1998).

Neuropsychological testing is also helpful for discerning cognitive functioning deficits of AD and other neurological/psychological disorders (Cammermeyer and Prendergast, 1997; Ritchie, 1997).

Assessment of Other Medical Conditions

Assessment of the patient's medical condition should include obtaining information about the client through structured interviews with the patient and a reliable informant and office-based clinical assessment (Small et al., 1997). Specific concerns include infectious disease, nutritional/feeding difficulties, bowel/urinary disorders, mobility problems, cardiovascular disease, pulmonary conditions, endocrine disease, coexisting neurological disorders, and decubitus ulcerations (Ham, 1997; Fabiszewski, 1988).

Standard laboratory tests for a work-up of dementia are directed toward identifying medical illnesses that can cause or contribute to cognitive symptoms. The consensus of many reviews supports the performance of a complete blood count, basic blood chemistries, thyroid function tests, and a vitamin B12 level (Knopman et al., 2001; Small et al., 1997). Imaging studies (computed tomography or magnetic resonance imaging [MRI]) may identify conditions other than neurodegeneration that could explain or contribute to the dementia symptoms. Anatomic imaging reveals clinically unexpected lesions in up to 5% of patients (Chui and Zhang, 1997; Knopman et al., 2001). However, the greatest promise of MRI may lie in its ability to quantitate the degree of brain atrophy.

Assessment of Behavioral Problems

The majority of AD patients experience some form of behavioral problems during the course of the disease (Small, et al., 1997; American Psychiatric Association, 1997). The patient should be carefully evaluated for general medical, psychiatric, or psychosocial problems that may underlie the disturbance (American Psychiatric Association, 1997). Patterns in the behavior's frequency, duration, potential triggers, and consequences should be documented. Challenging behaviors have differing causes, emerge at different points in the disease process, and present in a variety of manifestations (Cherry, 1997; Bolger, et al., 1994).

Psychotic symptoms are less common than the behavioral disturbances identified above; however, there is increased prevalence of psychotic symptoms as the disease progresses into the later stages (Hirono, et al., 1998). Delusions, paranoia and hallucinations are common and are of great concern since these symptoms are often linked to aggressive, combative behaviors (Gilley, et al., 1997; Small, et al., 1997; Koltra, et al., 1995). The Columbia University Scale for Psychopathology in AD is a brief and effective instrument to assess psychotic symptoms (Devanand, 1997).

Depression is underrecognised in older persons, and depression is a common disorder in AD patients (American Psychiatric Association, 1997; German, et al., 1985). Since administering assessment tests for depression to AD patients is often challenging (Warshaw, et al., 1995), gathering data from family members becomes especially important (Jones and Reifler, 1994).

Regular Reassessments

Longitudinal monitoring of therapies and regular health maintenance checkups are considered essential (Small, et al., 1997), and ongoing care should include medication review, treatment and monitoring of other medical conditions, treatment of dementia by available medications if appropriate, monitoring of disease progression, and referral to appropriate specialists (American Psychiatric Association, 1997).

Frequency of visits is determined by a number of factors including patient's clinical status, likely rate of change, current treatment plan, need for any specific monitoring of treatment effects, and reliability of skill of patients' caregivers (American Psychiatric Association, 1997). It is generally necessary to see patients in routine follow-up every six months, or sooner as indicated (American Psychiatric Association, 1997; Small, et al., 1997). More frequent visits (once or twice a week) may be required in the short-term for patients with complex or potentially dangerous symptoms, or during administration of specific therapies (American Psychiatric Association, 1997). Regular appointments will also monitor dementia-associated behaviors such as sleep disorders and agitation (Warshaw, et al., 1995), the development and evolution of cognitive and non-cognitive psychiatric symptoms and their response to intervention (American Psychiatric Association, 1997), provide regular patient surveillance of cognitive and functional status, and provide a forum for health promotion and maintenance activities (Small, et al., 1997).

Back Next HON Code Creative Commons License

Other features in PsyPlexus:

Directory of free articles for mental health professionals
Mental Health Reviews
Free-access review articles on mental health
Psychopharmacology Tips
Blog with tips on medicines for the mind
Mental Health Papyrus
Latest headlines from journals on mental health
PsyPlexus Newsletter
Features new additions to the site and useful tips
Page to search resources on mental health
Free Journals
Directory of free and open-access journals
PsyPlexus Directory
Selected websites on mental health
About Us Contact Us Ads Policy Privacy Policy