The PHQ-9 consists of 9 items representing the criterion symptoms for DSM 5 major depressive disorder.31 (link) Respondents are asked how much each symptom has bothered them over the past 2 weeks, with response options of “not at all”, “several days”, “more than half the days”, and “nearly every day”, scored as 0, 1, 2, and 3, respectively. The PHQ-9 can be scored as either a continuous variable from 0 to 27 (with higher scores representing more severe depression) or categorically using a diagnostic algorithm for major depressive or other depressive disorder. The GAD-7 has 7 items with response options identical to the PHQ-9 and therefore can be scored as a continuous variable from 0 to 21 (with higher scores representing more severe anxiety). Although originally developed as a measure to detect generalized anxiety disorder32 (link), the operating characteristics of the GAD-7 are nearly as good for the other common anxiety disorders in clinical practice – panic disorder, social anxiety disorder, and posttraumatic stress disorder.23 (link) The PHQ-9 and GAD-7 have strong internal and test-retest reliability as well as construct and factor-structure validity.20 (link) Moreover, both measures have proven sensitive to change when monitoring treatment response.20 (link);33 (link)-36 (link) The PHQ-ADS is the sum of the PHQ-9 and GAD-7 scores and thus can range from 0 to 48, with higher scores indicating higher levels of depression and anxiety symptomatology.