The relationship of DUP, DUI, negative symptom severity and functional outcome among people with psychosis in Hong Kong

Abstract

Empirical studies had demonstrated inconsistencies between duration of untreated psychosis (DUP) and outcome measures including negative symptoms severity and functional outcome. Therefore, this study aimed to investigate how either the construct of duration of untreated psychosis (DUP) or duration of untreated illness (DUI) acted on associating and predicting negative symptoms, its sub-domains and functional outcome among psychotic population in Hong Kong.

Totally three hundred and forty five subjects were recruited from in-patient and out-patient setting in hospitals under hospital authority. DUP and DUI were assessed by semi-interviewed with subjects, their family members and other significant others. And the Scale of Assessment of Negative Symptoms (SANS) and Social and Occupational Functioning Assessment Scale (SOFAS) were adopted as assessment tools to measure negative symptoms severity and functioning of individual respectively. Regression models were used to analyse how DUI and DUP differed in associating and predicting different variables.

Results showed that DUI took a more significant role in associating and predicting negative symptoms and functional outcome in which it demonstrated stronger positive correlation with negative symptoms and stronger negative correlation with functional outcome. DUI was also found to act as a potential predictor for both negative symptom severity and functional outcome. At the same time, among all sub-domains, anhedonia showed mild positive correlation with both DUI and DUP while other four didn’t show similar association.

The results provided increased insight that DUI might play a more significant role in determining the development of negative symptoms and functional outcome than DUP. Yet, limitations on various aspects had been addressed in this study such as the high level of heterogeneity of our sample and potential confounders which partially correlated with the outcome parameter. Also, no causal relationship had been yield between DUI / DUP and outcome variables. Further investigation was suggested on dividing the sample into sub-group to draw information regarding the characteristics of associations. Meanwhile, better control on potential confounding variables might help generating clearer picture on how independent variables associated with each other.