Specificity of trait anxiety in anxiety and depression: Meta-analysis of the State-Trait Anxiety Inventory.

The State-Trait Anxiety Inventory - Trait version (STAI-T) was developed to measure an individual's tendency to experience anxiety, but it may lack discriminant evidence of validity based on strong observed relationships with measures of depression. The present series of meta-analyses compares STAI-T scores among individuals with depressive disorders, anxiety disorders, and nonclinical comparison groups, as well as correlations with measures of anxiety and depressive symptom severity, in order to further examine discriminant and convergent validity. A total of 388 published studies (N = 31,021) were included in the analyses. Individuals with an anxiety disorder and those with a depressive disorder displayed significantly elevated scores on the STAI-T compared to nonclinical comparison groups. Furthermore, anxiety and depressive symptom severity were similarly strongly correlated with the STAI-T (mean r = .59 - .61). However, individuals with a depressive disorder had significantly higher STAI-T scores than individuals with an anxiety disorder (Hedges's g = 0.27). Given these findings, along with previous factor analyses that have observed a depression factor on the STAI-T, describing the scale as a measure of 'trait anxiety' may be a misnomer. It is proposed that the STAI-T be considered a non-specific measure of negative affectivity rather than trait anxiety per se.