Longitudinal Associations of Anxiety and Depression Among People Who Primarily Smoke Methamphetamine

Author: Zoe Duncan

Theme: Social Science & Policy Research Year: 2022

Methamphetamine users experience anxiety or depression at high rates. Much of the existing
literature is cross-sectional, involving participants recruited from drug treatment services or criminal
justice settings. There is a paucity of research examining associations between methamphetamine
use and anxiety. This study examined longitudinal patterns of anxiety and depression in communityrecruited cohort of methamphetamine smokers.
Data were derived from baseline and 6-monthly follow-up surveys conducted between August 2016
until March 2020. More than 800 participants from metropolitan and non-metropolitan areas of
Victoria were recruited for the prospective ‘VMAX’ study. Outcomes of interest—anxiety and
depression—were measured using the Generalized Anxiety Disorder (GAD)-7, and the Patient Health
Questionnaire (PHQ)-9 instruments. Frequency of methamphetamine use was measured by selfreported number of days per week in the past month. Generalised linear mixed models were used to
examine the association between frequency of methamphetamine use and ‘moderate-to-severe’
PHQ-9 and GAD-7 scores.
More than 60% of participants experienced depression and/or anxiety at baseline, and depression
and anxiety were highly correlated. Results indicated that increasing number of days per week of
methamphetamine use was associated with increased odds of experiencing either moderate-tosevere depression (OR=1.20, p<0.001) or anxiety (OR=1.19, p<0.001) over the course of the study.
Longitudinal associations of depression and anxiety and methamphetamine use emphasize the need
for integrated models of care. Further research is needed to examine longer-term longitudinal
trends and predictors of health service use for mental health issues amongst those experiencing
moderate-to-severe depression and/or anxiety.
Disclosure of Interest Statement:
The VMAX study was established with a grant from the Colonial Foundation and is now funded by
the National Health and Medical Research Council (NHMRC, 1148170). PD is supported by an
NHMRC Senior Research Fellowship. PD has received investigator-driven funding from Gilead
Sciences and Indivior for work unrelated to this study.

Download abstract