Prevalence of psychotic symptoms in patients presenting to a geriatric memory clinic in Hong Kong

Abstract

Objective: Neuropsychiatric symptoms are common amongst patients with dementia. However, the prevalence of psychotic symptoms and their associated factors in this group of patients are unclear, in particular the occurrence of hallucinations and delusions. We investigated the prevalence of psychotic symptoms and their associated factors in patients with dementia recruited from the specialist memory clinic. We then documented their prognosis and outcomes during follow-up for over one year. Method: We examined 317 case records of consecutive patients with mild cognitive impairment (31%) and dementia (69%) who attended the Specialist Memory Clinic at Queen Mary Hospital, between April and June 2015. We documented: a) the prevalence of psychotic symptoms; b) potential clinical factors which were related to these psychotic symptoms; and c) the follow-up of psychotic symptoms over the subsequent one year for 288 patients. Results: Among these 317 patients, the mean age was 78.3±8 years and 65% were female. The prevalence of hallucinations and delusions were 11.3% and 21.9%, respectively. Visual hallucination was the most prevalent type of hallucination (83%) while delusion of theft was the most common theme of delusion (75%). 19% of patients had either hallucinations or delusions and 7.1% reported both hallucinations and delusions. Patients with psychotic symptoms were more likely to be older, female and had more severe cognitive impairment. At one-year follow-up, of those who had no psychotic symptom at baseline, 12.7% had developed new psychotic symptoms; 9.2% had either hallucination or delusion, and 3.5% had both symptoms. Of those who had psychotic symptoms at baseline, 48% had no psychotic symptom at follow-up, whilst 21% had either hallucination or delusion, and 21% had both symptoms. Moreover, 21% of the psychotic patients at baseline had been referred to the psychogeriatric outpatient clinic, and 42% had been prescribed antipsychotic medications. Conclusion: Psychotic symptoms are highly prevalent amongst older patients with dementia in the Memory Clinic in Hong Kong, many of them have both hallucinations and delusions, causing significant morbidity. One in eight patients with no psychotic symptoms develops new psychotic symptoms each year.