The cognitive deficits above each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning. The decline in mental functioning begins gradually and worsens steadily. I disorder such as a Depressive Disorder or Schizophrenia.
Some disorders have similar or even overlapping symptoms.
The clinician, therefore, in his diagnostic attempt has to differentiate against the following disorders which need to be ruled out to establish a precise diagnosis. Alzheimer's Disease is defined by the National Institute on Ageing as progressive, irreversible declines in memory, performance of routine tasks, time and space orientation, language and communication skills, abstract thinking, and the ability to learn and carry out mathematical calculations. Other symptoms include personality changes and impaired judgement. Although a direct cause of Alzheimer's is not known certain common factors are found in the clinical picture of suffers. Use of medications to treat cognitive decline and memory loss.