FRIDAY, Jan. 2, 2026 (HealthDay News) -- There is widespread misinterpretation of the instructions for responding to the Patient Health Questionnaire (PHQ), which is used to measure severity of depression, according to a study published online Dec. 17 in JAMA Psychiatry.Margarita Panayiotou, Ph.D., from the University of Manchester in the United Kingdom, and colleagues examined how participants responded to the PHQ in a general population sample collected via Amazon Mechanical Turk (MTurk; 503 participants) and a clinical sample with medium to high depression from the Operationalizing Digital PhenoTyping in the Measurement of Anhedonia (OPTIMA) study (349 participants). Participants' interpretation of instructions was assessed via three questions after completing the PHQ-8: how they would respond to the PHQ sleep item in a hypothetical scenario where they overslept nearly every day and were comfortable with doing so; whether they had based their PHQ responses on symptom frequency, bothersomeness of symptoms, or both; and how they would respond to PHQ in the future.The researchers found that in the hypothetical oversleeping scenario, only 54.7 and 15.5 percent of participants from MTurk and OPTIMA, respectively, interpreted the PHQ as instructed according to the frequency with which the problem bothered them. Only 21.3 and 11.7 percent of participants from MTurk and OPTIMA, respectively, interpreted the instructions as instructed, and 22.3 and 9.9 percent reported that they would do so in the future. The validity of the PHQ-8 varied depending on how participants interpreted its instructions."Most of the time when we use these questionnaires we want to know about symptoms of depression, so the 'bothered by' part really matters," lead author Zachary Cohen, Ph.D., from the University of Arizona in Tucson, said in a statement.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter