The effects of loneliness and psychological flexibility on veterans' substance use and physical and mental health functioning during the COVID-19 pandemic.

During the COVID-19 pandemic, social isolation was a common experience as people were trying to keep themselves and others safe from infection. Veterans with problematic substance use are at particular risk of the consequences of social isolation. This study evaluated the nature of social interactions during the COVID-19 pandemic and the effects of loneliness and psychological flexibility on self-reported substance use and physical and mental health functioning among U.S. veterans who reported problematic substance use. Data from 409 veterans with self-reported substance use concerns were obtained via a cross-sectional online survey. Results showed that many veterans who engaged in problematic substance use during the COVID-19 pandemic reported a number of social supports during this period and frequent communication with others, but still felt lonelier during the pandemic. In regression analyses, higher levels of loneliness were associated with more negative impacts of the pandemic, greater substance use, and poorer physical and mental health functioning. Psychological flexibility demonstrated significant unique variance in explaining mental health functioning during the pandemic after accounting for loneliness, but not for substance use or physical functioning. For veterans with high levels of loneliness, high levels of psychological flexibility were associated with a lower negative impact on quality of life due to the pandemic, but for veterans with low levels of loneliness, differing levels of psychological flexibility were not significantly associated with the negative impact of COVID-19. Overall, loneliness and psychological flexibility appear to be highly associated with the negative impact of COVID-19 on veterans with problematic substance use.