Phantom Boarder Symptom in Dementia

Objective: Phantom boarder symptom (PBS), which has been labelled a misidentification and is commonly observed in cases of Alzheimer's disease, is the perceptual dysfunction where it is imagined that there are people in the home. It may also be encountered in cases of vascular dementia and other variants of this cognitive dysfunction. This study was undertaken to investigate PBS frequency and characteristics for a sample of dementia inpatients, and to determine the strength of the association with other psychotic symptoms.

Methods: The sample population consisted of 240 dementia patients admitted to our geropsychiatric ward. Patients with and without PBS were compared in terms of general characteristics and psychotic symptoms.

Results: Of the 240 dementia patients, PBS was identified in 56 (23.3%). There were no significant gender differences between the PBS and non-PBS groups. Means for age and onset-age were higher for the PBS group, and the prevalence of hallucinations and other misidentifications was greater compared to the non-PBS analog. Occurrence of PBS was not significantly associated with delusions or physical aggression.

Conclusions: PBS is a common symptom in dementia of various etiologies. Our association findings suggest that it may be more productive to classify PBS as a type of misidentification, instead of as a delusion.