Construct Validity of the Perceived Stress Scale 4 in a Norwegian Adult ADHD Community Population.

Stress is a potential risk factor for other serious health concerns. Studies show an association between Attention-Deficit/Hyperactivity Disorder (ADHD) and stress due to impairments in emotional regulation and executive functioning that are typical of the disorder. The Perceived Stress Scale (PSS) is among the most widely used measures of perceived stress, and its four-item version (PSS-4) lacks validation in Norwegian contexts. This study aims to evaluate the construct validity of the PSS-4 in an adult ADHD sample, to facilitate effective and valid measurements of perceived stress in this population. A total of 423 adults with ADHD were recruited through a Norwegian user involvement organization. Confirmatory factor analysis with a two- and a one-factor model was applied. Gradually, more restricted models were evaluated in terms of model fit and compared with each other to test measurement invariance across sexes. Pearson correlations were calculated for the association with related constructs. Our results favored the two-factor model, which demonstrated a good fit, over the one-factor model. Our results indicated that the PSS-4 posits measurement invariance across sexes at the configural, metric, and scalar levels. All correlations aligned with expected directions and strengths. These results indicate that the Norwegian PSS-4 posits good construct and structural validity, and measurement invariance across sexes in this population. In sum, our results support the use of the PSS-4 as a short and valid measure of perceived stress among adults with ADHD.