Dementia Services Information and Development Centre


The diagnosis of a dementia is made by a medical doctor – either a General Practitioner or a hospital doctor such as a Geriatrician (specialist in the diagnosis and treatment of physical and chronic health problems of older people), Old Age Psychiatrist (specialist in the diagnosis and treatment of mental health problems in older people) Neurologist (medical specialist in brain disorders) or at a Memory Clinic (specialist service usually hospital based and dealing in the assessment and diagnosis of memory problems.

An internationally agreed set of criteria for diagnosing dementia has been established.  These criteria are laid out in the Diagnostic and Statistical Manual of Mental Disorders (DSM) published by the American Psychiatric Association. This manual is currently in its’ fifth edition, DSM-5.

It is generally accepted that for a diagnosis multiple cognitive deficits must be present these include:

  1. Evidence of short and long term memory impairment and;
  2. At least one of the following:
    - Aphasia (communication problems)
    - Apraxia (the loss or impairment of the ability to execute complex coordinated movements without muscular or sensory impairment)
    - Agnosia (the loss or diminution of the ability to recognise familiar objects or stimuli, usually as a result of brain damage)
    - Impaired Executive Function (this term is often used to explain behaviours and refers to higher level cognitive abilities that enable an individual to successfully engage in independent goal-directed behavior e.g. planning, sequencing, problem solving, decision making)
  3. Disturbances in 1 and 2 result in significant problems with employment and/or social functioning