Validation therapy was developed by Naomi Feil for older people with cognitive impairments and dementia

Dementia

Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

. 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
  Orientation (mental)
  Orientation is a function of the mind involving awareness of three dimensions: time, place and person. Problems with orientation lead to disorientation, and can be due to various conditions, from delirium to intoxication...
  
  
• Time Confusion
  Mental confusion
  Confusion of a pathological degree usually refers to loss of orientation sometimes accompanied by disordered consciousness and often memory Confusion (from Latin confusĭo, -ōnis, noun of action from confundere "to pour together", also "to confuse") of a pathological degree usually refers to loss...
  
  
• Repetitive Motion
  Stereotypy
  A stereotypy is a repetitive or ritualistic movement, posture, or utterance, found in people with mental retardation, autism spectrum disorders, tardive dyskinesia and stereotypic movement disorder. Stereotypies may be simple movements such as body rocking, or complex, such as self-caressing,...
  
  
• Vegetative state.

The basic principle of the therapy is the concept of validation

Compliance (psychology)

Compliance refers to a response — specifically, a submission — made in reaction to a request. The request may be explicit or implicit . The target may or may not recognize that he or she is being urged to act in a particular way.Social psychology is centered on the idea of social influence...

 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.

Validation therapy uses different specific techniques, and it has attracted criticism from researchers who dispute the evidence for some of the beliefs and values of validation therapy, and the appropriateness of the techniques; as there are not enough quality evidences proving the efficacy

Efficacy

Efficacy is the capacity to produce an effect. It has different specific meanings in different fields. In medicine, it is the ability of an intervention or drug to reproduce a desired effect in expert hands and under ideal circumstances.- Healthcare :...

of such method for people with dementia.