Abstract
Objective: To develop a scale measuring good outcome in persons with psychosis using items from the National Study of Low Prevalence (Psychotic) Disorders; to determine a cut-off for delineating good outcome cases from other cases; and to examine factors associated with good outcome using data from the same study.
Method: During the census conducted as part of the Australian National Survey of Mental Health and Wellbeing Study of Low Prevalence Disorders, a total of 5,710 individuals were screened for symptoms of psychosis; 3,800 of these were screened-positive. A random sample of 980 individuals who were screened positive for psychosis were subsequently interviewed. A scale measuring good outcome was developed using items selected from the interview schedule, and its psychometric properties were established using data for the interviewed sample of 980 individuals. A cut-off delineating good outcome cases from other cases was determined. Subsequently the good outcome cases in the sample were compared with the other cases on a number of characteristics in order to assess factors associated with good outcome in psychosis.
Results: We found a significant minority of 185 individuals who met the cut-off for ‘good outcome’. When these individuals were compared with the rest of the sample, we found that both groups had experienced similar levels of symptomatology (including mood disturbance and affective symptoms, hallucinations and delusions) over a lifetime, but the percentage in the ‘good outcome’ group currently experiencing these symptoms was much lower. In addition, differences were observed between the two groups with respect to selected socio-demographic variables, lifestyle factors, premorbid characteristics and the use of treatment services.
Conclusions: Our comparison of the two groups is based on descriptive statistics which do not answer questions of causality such as whether better, initial social circumstances are the cause of good outcome in psychosis, or whether good outcome is a consequence of a disease process that has a ‘milder’ natural history. Further work is required using longitudinal data in order to examine more closely causal relationships between the factors identified and outcome in psychosis.