An empirical investigation of psychosis proneness among amphetamine users: Current and predictive validity
NDARC Staff
Rebecca McKetin and Maree Teesson
Other Investigators
Sharon Dawe (Griffith University), David Kavanagh (University of Queensland), Ross Young (Queensland University of Technology), and John Saunders (University of Queensland)
Rationale
Methamphetamine can cause psychotic symptoms in some people, but currently there are sparse data on the relationship between methamphetamine use and psychotic symptoms.
Aims
This project was conducted through Griffith University in collaboration with the National Drug and Alcohol Research Centre. The project aimed to investigate:
- the relationship between dose, pattern and duration of amphetamine use and emergent psychotic symptoms
- the relative contribution of amphetamine dose, schizotypal features and family history of schizophrenia on the increase of positive psychotic symptoms
- the progression of psychotic symptoms over time, and specifically what is the evidence for the development of sensitisation to amphetamine such that smaller doses precede an increase in psychotic symptoms
Design and Method
A cohort of 158 methamphetamine users were recruited from needle and syringe exchange programs in inner Brisbane, Melbourne and Sydney. The cohort underwent a detailed assessment of psychosis and drug use history at baseline using the PRISM (Psychiatric Research Interview for Substance and Mental Disorders), and was then followed up at one-month intervals over one year. Follow-up interviews included assessment of drug use (Timeline Follow Back) and positive psychotic symptoms (Brief Psychiatric Rating Scale) in the past 30 days. Traits measures of psychosis included the Oxford-Liverpool Inventory of Feelings and Experiences.
Benefits
The data from this project will help understand the relationship between methamphetamine use and psychotic symptoms.
Output
Data collection for this project is complete. Data analysis and reporting will commence soon.
Funding
National Health and Medical Research Council