Validation therapy was developed by Naomi Feil for older people with cognitive impairments and dementia. Feil's own approach classifies individuals with cognitive impairment as having one of four stages in a continuum of dementia. These stages are:

• Mal orientation
• Time confusion
• Repetitive motion
• Vegetative state

The basic principle of the therapy is the concept of validation or the reciprocated communication of respect which communicates that the other's opinions are acknowledged, respected, heard, and (regardless whether or not the listener actually agrees with the content), they are being treated with genuine respect as a legitimate expression of their feelings, rather than marginalized or dismissed.

Criticism argue that there is insufficient evidence from randomized trials to allow any conclusion about the efficacy of validation therapy for people with dementia or cognitive impairment. ^[1]