Abstract
Research on concept creep indicates that the meanings of some psychological concepts have broadened in recent decades. Some mental health-related concepts such as 'trauma', for example, have acquired more expansive meanings and come to refer to a wider range of events and experiences. 'Anxiety' and 'depression' may have undergone similar semantic inflation, driven by rising public attention and awareness. Critics have argued that everyday emotional experiences are increasingly pathologized, so that 'depression' and 'anxiety' have broadened to include sub-clinical experiences of sadness and worry. The possibility that these concepts have expanded to include less severe phenomena (vertical concept creep) was tested by examining changes in the emotional intensity of words in their vicinity (collocates) using two large historical text corpora, one academic and one general. The academic corpus contained >133 million words from psychology article abstracts published 1970-2018, and the general corpus (>500 million words) consisted of diverse text sources from the USA for the same period. We hypothesized that collocates of 'anxiety' and 'depression' would decline in average emotional severity over the study period. Contrary to prediction, the average severity of collocates for both words increased in both corpora, possibly due to growing clinical framing of the two concepts. The study findings therefore do not support a historical decline in the severity of 'anxiety' and 'depression' but do provide evidence for a rise in their pathologization.