Trajectories of loneliness during COVID‐19 pandemic and associations with mental health and substance use.

We examined patterns of longitudinal trajectories of loneliness during the COVID‐19 pandemic using six time points (January 2020 [pre‐pandemic] to March/April 2021) and whether trajectories were associated with psychological distress (depression/anxiety) and substance use (alcohol/cannabis) outcomes in Spring 2021. Participants were 644 young adults who completed online assessments. Outcomes were regressed on most‐likely loneliness trajectory adjusting for pre‐pandemic measures. Three loneliness trajectories varied from consistently lower to consistently higher. Pre‐pandemic social support was associated with lower odds of a higher loneliness trajectory. Higher loneliness trajectories were associated with greater odds of past‐month cannabis use compared to Low trajectories, but not significantly associated with depression, anxiety, or alcohol use in Spring 2021. Interventions addressing co‐occurring loneliness and cannabis use are needed. [ABSTRACT FROM AUTHOR]