Testing Invariance of Measures of Internalizing Symptoms Before and After a Major Life Stressor: The Impact of COVID-19 in an Adolescent and Young Adult Sample.

There are reports of increases in levels of internalizing psychopathology during the COVID-19 pandemic. However, these studies presume that measurement properties of these constructs remained unchanged from before the pandemic. In this study, we examined longitudinal measurement invariance of assessments of depression, anxiety, and intolerance of uncertainty (IU) in adolescents and young adults from ongoing longitudinal studies. We found consistent support for configural and metric invariance across all constructs, but scalar invariance was unsupported for depression and IU. Thus, it is necessary to interpret pandemic-associated mean-level changes in depression and IU cautiously. In contrast, mean-level comparisons of panic, generalized, and social anxiety symptoms were not compromised. These findings are limited to the specific measures examined and the developmental period of the sample. We acknowledge that there is tremendous distress accompanying disruptions due to the COVID-19 outbreak. However, for some instruments, comparisons of symptom levels before and during the pandemic may be limited.