Interested readers will find this booklet useful for screening family and friends, in regard to the common complaints of age-associated decline in memory and thinking. Dr Johnston is quite right in stating that many patients with Alzheimer's disease go undiagnosed and untreated until moderate stages of the disease, and effective treatments, both pharmacologic and non pharmacologic, are often delayed.

Much remains to be learned about the causes of Alzheimer's disease. We have made a good start and there is cautious optimism that prevention, e.g. delaying the emergence of symptoms by 5 to 10 years, will be possible. For the persons who already have dementia and their families, much can be done to help. Please consult your family doctor if the symptoms and signs such as an abnormal clock test are present in your family member or friend. Most will be found to have other causes of memory and thinking impairment, but some will be in the early stages of Alzheimer's disease, and treatments can be initiated.

Serge Gauthier, MD, FRCPC. Neurologist