Measuring depression and anxiety in autistic college students: A psychometric evaluation of the PHQ-9 and GAD-7.

Lay abstract: Anxiety, depression, and suicidality are major concerns among college students, though less is known about these constructs in autistic college students. Given the rising number of autistic individuals entering college, adequate screening and diagnosis of mental health difficulties is necessary to provide care to this population. For example, despite widespread usage of the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), it is unknown if the two instruments accurately measure depression and anxiety the same way between non-autistic and autistic individuals. Thus, the current study was the first to examine how these instruments measure depression and anxiety symptoms in autistic versus non-autistic college students. Utilizing tests of construct measurement in a sample of autistic (n = 477) and non-autistic (n = 429) university students aged 18-29, results showed that while the GAD-7 and PHQ-9 appear to be accurately capturing anxiety and depression in autistic college students, the PHQ-9 item assessing suicidality was found to be measuring different things. This indicates that autistic college students are not interpreting this question the way non-autistic students are, and thus, the measure is failing to capture suicidality in autistic people. Future investigators should continue to assess the appropriateness of using common screening measures, originally created by non-autistic people, in autistic populations.