Apathy Associated With Alzheimer's Disease

Sunnybrook Health Sciences Centre

Status and phase

Completed

Phase 4

Conditions

Alzheimer Disease

Dementia

Treatments

Drug: Dextroamphetamine

Drug: Methylphenidate

Study type

Interventional

Funder types

Other

Identifiers

NCT00254033

065-2003

AHAF Grant Number: A2003-236

Details and patient eligibility

About

Apathy, or lack of motivation, affects up to 80% of Alzheimer's disease (AD) patients. These amotivational symptoms increase patient reliance on caregivers, increase caregiver burden and distress, and increase the risk of patient institutionalization. Only 50% of patients with apathy respond to current treatment with cholinesterase inhibitors. The mechanism of apathy in AD is unknown hampering rational treatment. Our proposed pilot study will provide initial data required to develop an amphetamine challenge paradigm to probe the brain reward system. These results will be used to develop a larger study evaluating the role of the brain reward system in apathy in AD and link this information with pharmacologic treatment. AD is a complex neurobiological illness that needs to be understood at several levels to optimize treatment. At a neurochemical level, one has to identify the neurotransmitter abnormalities that accompany the clinical symptoms. The neurochemical level of analysis provides the link between pathology and symptoms and, for now, is the only avenue for biological therapies. Next, one has to translate knowledge of neurochemical abnormalities to practical treatments for the symptoms of AD. This pilot will allow us to develop a study that can address both of these goals. Furthermore, the larger study will further define the emerging concept of apathy as a syndrome and has broader implications for apathy in many other neuropsychiatric diseases.

Sex

All

Ages

55+ years old

Volunteers

No Healthy Volunteers

Inclusion criteria

age > 55 years
meet DSM-IV criteria for primary degenerative dementia
meet NINCDS-ARDA criteria for probable Alzheimer's Disease of at least one year's duration
mild to moderate cognitive impairment (Global Deterioration Scale GDS <6, Mini-Mental State Examination >10
on a stable dose of a cholinesterase inhibitor for at least 3 months
apathetic group only: Neuropsychiatric Inventory (NPI) Apathy subscale score >=2

Exclusion criteria

abnormal biochemical screening: blood cell count, vitamin B12, thyroid function tests, and syphilis screening tests
significant medical illness or other medical/neurological conditions which diminish cognitive function
evidence of seizure disorder
an Hachinski ischemic score >3 indicating vascular dementia
a brain computed tomographic (CT) scan revealing focal lesions, or inconsistent with AD
electrocardiographic, laboratory or physical evidence of significant cardiovascular disease
presence of premorbid or current psychiatric diagnosis including: major depression, schizophrenia, psychotic symptoms of a severity likely to provoke violent or dangerous behaviour (i.e., command hallucinations to harm people or persecutory delusions that provoke violent reactions)
current or past psychoactive substance abuse or dependence (including alcohol, excluding nicotine)
contraindications to receiving dextroamphetamine or methylphenidate
have had administration of a depot neuroleptic injection within one treatment cycle of the first visit