THE VALIDITY OF INFORMANT REPORTS IN ASSESSING THE SEVERITY OF DEMENTIA - EVIDENCE FROM THE CAMDEX INTERVIEW

The evaluation of a patient's mental state, overall clinical profile a nd behavioural disturbance in the process of diagnosing dementia requi res at least two sources of information: the patient and the informant . Since the severity of the dementia may interfere with the subjective perception of these disorders, it is important to evaluate the consis tency between these two sources of information and the clinical and ps ychometric evaluation made by the physician. Accordingly, in this stud y five behavioural areas, derived from the semi-structured interview s chedule provided by the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX, i.e., Sleep, Depressed Mood, Everyday Activity, M emory and Global Mental Functioning) have been tested on the patient a nd his/her informant. Eighty dementia patients (mean age = 74 years) a nd their informants participated in the study. The dementia group was subdivided into two levels of severity according to DSM-IIIR criteria: 41 with mild dementia and 39 with moderate dementia, respectively, ma tched for age and schooling. The rating of impairment was found to inc rease along with the severity of dementia in all the above-mentioned a reas, except for sleep. However, the source of information pel se sign ificantly influenced the evaluation of memory functioning. Moreover, t he significant interaction between the two factors considered indicate s that memory functioning is evaluated quite differently by the patien ts and the informants, as only in the assessment made by the latter gr oup did the impairment increase in parallel with severity of dementia. Finally, whereas none of the subjective measures recorded in the pati ents were significantly correlated with their test scores, the correla tions between the informant memory appraisals and patient test results proved to be significant. The present findings confirm the validity o f informant reports in assessing cognitive and memory disorders in ear ly-stage dementia, as well as in distinguishing patients with mild fro m those with moderate dementia.