G1. There is evidence of each of the following:

1. A decline in memory, which is most evident in the learning of new information, although, in more severe cases, the recall of previously learned information may also be affected. The impairment applies to both verbal and nonverbal material. The decline should be objectively verified by obtaining a reliable history from an informant, supplemented, if possible, by neuropsychological tests or quantified cognitive assessments. The severity of the decline, with mild impairment as the threshold for diagnosis, should be assessed as follows:
   Mild. The degree of memory loss is sufficient to interfere with everyday activities, though not so severe as to be incompatible with independent living. The main function affected is the learing of new material. For example, the individual has difficulty in registering, storing, and recalling elements involved in daily living, such as where belongings have been put, social arrangements, or information recently imparted by family members.
   Moderate. The degree of memory loss represents a serious handicap to independent living. Only highly learned or very familiar material is retained. New information is retained only occasionally and very briefly. Individuals are unable to recall basic information about their own local geography, what they have recently been doing, or the names of familiar people.
   Severe. The degree of memory loss is characterized by the complete inability to retain new information. Only fragments of previously learned information remain. The individual fails to recognize even close relatives.
2. A decline in other cognitive abilities characterized by deterioration in judgment and thinking, such as planning and organizing, and in the general processing of information. Evidence for this should ideally be obtained from an informant and supplemented, if possible, by neuropsychological tests or quantified objective assessments. Deterioration from a previously higher level of performance should be established. The severity of the decline, with mild impairment as the threshold for diagnosis, should be assessed as follows:
   Mild. The decline in cognitive abilities causes impaired performance in daily living, but not to a degree that makes the individual dependent on others. Complicated daily tasks or recreational activities cannot be undertaken.
   Moderate. The decline in cognitive abilities makes the individual unable to function without the assistance of another in daily living, including shopping and handling money. Within the home, only simple chores can be performed. Activities are increasingly restricted and poorly sustained.
   Severe. The decline is characterized by an absence, or virtual absence, of intelligible ideation.

The overall severity of the dementia is best expressed as the level of decline in memory or other cognitive abilities, whichever is the more severe (e.g., mild decline in memory and moderate decline in cognitive abilities indicate a dementia of moderate severity).
G2. Awareness of the environment (i.e., absence of clouding of consciousness [as defined in delirium, not induced by alcohol and other psychoactive substances. Criterion A]) is preserved during a period sufficiently long to allow the unequivocal demonstration of the symptoms in Criterion G1. When there are superimposed episodes of delirium, the diagnosis of dementia should be deferred.
G3. There is a decline in emotional control or motivation, or a change in social behavior manifest as at least one of the following:

1. emotional lability
2. irritability
3. apathy
4. coarsening of social behavior

G4. For a confident clinical diagnosis, the symptoms in criterion G1 should have been present for at least 6 months; if the period since the manifest onset is shorter, the diagnosis can be only tentative.
Comments
The diagnosis is further supported by evidence of damage to other higher cortical functions, such as aphasia, agnosia, apraxia.
Judgment about independent living or the development of dependence (upon others) should take account of the cultural expectation and context.
Dementia is specified here as having a minimum duration of 6 months to avoid confusion with reversible states with identical behavioral syndromes, such as traumatic subdural hemorrhage, normal pressure hydrocephalus, and diffuse or focal brain injury.
A fifth character may be used to indicate the presence of additional symptoms: Dementia in Alzheimer's disease, vascular dementia, dementia in diseases classified elsewhere, unspecified dementia, as follows:
   Without additional symptoms
   With other symptoms, predominantly delusional
   With other symptoms, predominantly hallucinatory
   With other symptoms, predominantly depressive
   With other mixed symptoms
A sixth character may be used to indicate the severity of the dementia:
   Mild
   Moderate
   Severe
As mentioned above, the overall severity of the dementia depends on the level of memory or intellectual impairment, whichever is the more severe.