The Patient Health Questionnaire is a multiple-choice self-report inventory copyrighted by Pfizer Inc, that is used as a screening and diagnostic tool for mental health disorders of depression, anxiety, alcohol, eating, and somatoform disorders. It is the self-report version of the Primary Care Evaluation of Mental Disorders, a diagnostic tool developed in the mid-1990s by Pfizer Inc. The length of the original assessment limited its feasibility; consequently, a shorter version, consisting of 11 multi-part questions – the Patient Health Questionnaire was developed and validated.