Direction of the relationship between methamphetamine use and positive psychotic symptoms in regular methamphetamine users: evidence from a prospective cohort study

Leanne Hides; Gary Chan; Sharon Dawe; Rebecca McKetin; David J Kavanagh; Ross McD Young; Maree Teesson; John B Saunders

doi:10.1192/bjp.2019.263

Direction of the relationship between methamphetamine use and positive psychotic symptoms in regular methamphetamine users: evidence from a prospective cohort study

Br J Psychiatry. 2021 Jul;219(1):361-367. doi: 10.1192/bjp.2019.263.

Authors

Leanne Hides¹, Gary Chan², Sharon Dawe³, Rebecca McKetin⁴, David J Kavanagh⁵, Ross McD Young⁶, Maree Teesson⁷, John B Saunders⁸

Affiliations

¹ Professor in Clinical Psychology, Lives Lived Well Chair of Alcohol, Drugs and Mental Health, Centre for Youth Substance Abuse Research, School of Psychology, The University of Queensland, Australia.
² Research Fellow, Centre for Youth Substance Abuse Research, School of Psychology, The University of Queensland, Australia.
³ Professor in Clinical Psychology, School of Applied Psychology, Griffith University, Australia.
⁴ Associate Professor, National Drug and Alcohol Research Centre, University of New South Wales, Australia.
⁵ Research Capacity-Building Professor, Centre for Children's Health Research, Institute of Health and Biomedical Innovation, School of Psychology and Counselling, Queensland University of Technology (QUT), Australia.
⁶ Executive Dean, Faculty of Health, Centre for Children's Health Research, Institute of Health and Biomedical Innovation, School of Psychology and Counselling, Queensland University of Technology (QUT), Australia.
⁷ Professor and Director of the Matilda Centre for Research in Mental Health and Substance Use, University of Sydney, Australia.
⁸ Professor and Consultant Physician in Internal Medicine and Addiction Medicine, Centre for Youth Substance Abuse Research, School of Psychology, The University of Queensland; and Disciplines of Psychiatry and Addiction Medicine, Faculty of Medicine, University of Sydney, Australia.

PMID: 31950892
DOI: 10.1192/bjp.2019.263

Abstract

Background: Methamphetamine has been consistently associated with positive psychotic symptoms, but little is known about whether the reverse also occurs.

Aims: This study determined whether the relationship between methamphetamine use and positive psychotic symptoms is bidirectional over 12 months. The impact of lifetime psychotic disorders and methamphetamine dependence on these relationships was also examined.

Method: A total of 201 regular (at least monthly) primary methamphetamine users were recruited from free needle and syringe programmes in three Australian cities. Data on the frequency of methamphetamine and other drug use (from Timeline Followback inteviews) and the severity of positive psychotic symptoms (using the Brief Psychiatric Rating Scale) in the past 2 weeks were collected in 12 contiguous monthly face-to-face interviews (mean of 9.14/11 (s.d. = 3.16) follow-ups completed). Diagnoses were derived using the Psychiatric Research Interview for DSM-IV Substance and Mental Disorders.

Results: The mean age of participants was 31.71 years (s.d. = 8.19) and 39% (n = 77) were women. At baseline 55% (n = 110) were dependent on methamphetamine and 51% (n = 102) had a lifetime psychotic disorder. Cross-lagged dynamic panel models found a significant bidirectional relationship between psychotic symptoms and methamphetamine use (Comparative Fit Index (CFI) = 0.94, standardised root mean square residual (SRMR) = 0.05, root mean square error of approximation (RMSEA) = 0.05, 95% CI 0.04-0.06). The magnitude of the relationship in each direction was similar, and the presence of methamphetamine dependence or a lifetime psychotic disorder did not have an impact on results.

Conclusions: A dynamic, bidirectional relationship between methamphetamine and psychotic symptoms of similar magnitude in each direction was found over 1 year. This suggests integrated treatments that target methamphetamine, psychotic symptoms and their interrelationship may be of most benefit.

Keywords: Psychotic symptom; bidirectional; methamphetamine; prospective; psychosis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Amphetamine-Related Disorders* / complications
Amphetamine-Related Disorders* / diagnosis
Amphetamine-Related Disorders* / epidemiology
Australia / epidemiology
Female
Humans
Methamphetamine* / adverse effects
Prospective Studies
Psychoses, Substance-Induced* / epidemiology
Psychoses, Substance-Induced* / etiology
Psychotic Disorders* / psychology

Substances

Methamphetamine