This application allows users to us the PHQ-9 self-questionnaire to quickly self-test whether they might have major depression. Additionally it provides users with a severity score of their depressive symptoms. This involves nine easy to answer questions. Depression is one of the most prevalent and treatable mental disorders. Diagnosis of depression is based on the presence of certain symptoms that significantly impair function for a certain duration. These symptoms are described in the DSM-IV, the diagnostic manual for mental disorders. The PHQ-9 test consists of the actual nine criteria on which the diagnosis of DSM-IV depressive disorders is based. The diagnostic validity of the PHQ-9 is fully evidence based [1, 2]. The test has comparable sensitivity and specificity to many other extensive depression measures. Please note: This self-test is meant to give you insight in your mood state. This test is explicitly not suitable for diagnosis. This test cannot replace professional help. When in doubt, please always contact your general practitioner. No rights can be derived from the results of this test. Key words: depression, test, tracking, track, graph, psychiatry, disorder, major depression, stress, emotion, mood, happy, happiness, sad, down  Spitzer RL et al., Validation and utility of a self-report version of PRIME-MD: the PHQ primary care study. Primary Care Evaluation of Mental Disorders. Patient Health Questionnaire.JAMA. 1999 Nov 10;282(18):1737-44.  J Kroenke K et al. The PHQ-9: validity of a brief depression severity measure. Gen Intern Med. 2001 Sep;16(9):606-13.