Peak-end bias in retrospective recall of depressive symptoms on the PHQ-9

Mental health care is built around patient recall and report of clinical symptoms. However, memories of events and experiences rely on cognitive heuristics that influence our recall. The peak-end bias, which refers to the tendency for the most intense and proximate aspects of an experience to disproportionately influence our memory, has been understudied in the context of mental health symptoms and may unduly influence self-reported symptoms, even in the context of standardized assessments. To determine whether the peak-end bias applies to the report of depressive symptoms on the standardized Patient Health Questionnaire-9 (PHQ-9) assessment, we compared two scores from daily mood assessments collected over a 2-week period from 4,322 medical interns (56% women; 60% non-Hispanic White). The peak-end-mood score, which averaged the single lowest and most recent mood scores over 2 weeks had a significantly stronger correlation with the PHQ-9 than the mean-mood score, which averaged all mood scores during the 2 weeks. Likelihood ratio tests and fit statistics provided further support that the peak-end-mood score was a significantly better predictor of depression than the mean-mood score. Results were consistent when limiting the sample to those with mild-to-severe depressive symptoms, and when only examining the two primary mood items as the dependent variable. These findings provide evidence for a modest peak-end recall bias for mood and depressive symptoms. There may be benefits to implementing intermittent assessment strategies to support clinical decision-making. (PsycInfo Database Record (c) 2023 APA, all rights reserved).