Prior research indicates rising methamphetamine use and harms in the U.S., potentially related to increases in methamphetamine injection. To date, research on trends and correlates of methamphetamine injection is limited.

Analysis of trends and correlates of methamphetamine injection among treatment admissions among persons aged ≥ 12 whose primary substance of use at admission is methamphetamine. Data are from the Treatment Episode Data Set. Analyses includes descriptive statistics, trend analyses, and multilevel multivariable logistic regression.

Primary methamphetamine treatment admissions increased from 138,379 in 2010 to 201,021 in 2019. Among primary methamphetamine admissions, injection as the usual route of use increased from 24,821 (18.0 % of admissions) in 2010 to 55,951 (28.2 % of admissions) in 2019. Characteristics associated with increased adjusted odds of reporting methamphetamine injection included: males (aOR = 1.13, 95 % CI = 1.10–1.15); admission age 25–34 years (aOR = 1.23, 95 % CI = 1.19–1.28) and 35–44 years (aOR = 1.12, 95 % CI = 1.08–1.17) compared to age 18–24; dependent living (aOR = 1.33, 95 % CI = 1.29–1.37) and homelessness (aOR = 1.58, 95 % CI = 1.54–1.63) compared to independent living; part-time employment (aOR = 1.08, 95 % CI = 1.02–1.14), unemployment (aOR = 1.39, 95 % CI = 1.34–1.44) and not in labor force (aOR = 1.43, 95 % CI = 1.37–1.49) compared to full-time employment; one to ≥ four prior treatment admissions (aORs ranging from 1.19 to 1.94) compared to no prior admissions; also reporting use of cocaine (aOR = 1.10, 95 % CI = 1.05–1.16), heroin (aOR = 3.52, 95 % CI = 3.40–3.66), prescription opioids (aOR = 1.61, 95 % CI = 1.54–1.67), or benzodiazepines (aOR = 1.42, 95 % CI = 1.32–1.52) at treatment admission.

Findings lend further evidence to a resurgence of methamphetamine use that is intertwined with the ongoing opioid crisis in the U.S. Efforts to expand evidence-based prevention, treatment, and response efforts, particularly to populations at highest risk, are urgently needed.