This dataset contains 14 days of ambulatory assessment (AA) depression symptoms and mood ratings with timestamps, a retrospective Patient Health Questionnaire (PHQ-9) assessment and the demographic variables age and gender. The AA was conducted with users of the mobile mental health / depression screening app "Moodpath". ICD-10 depression symptoms were assessed with the following questions: ICD-10 symptom 1: "depressed mood" q1 = Are you feeling depressed? q2 = Are you feeling hopeless? ICD-10 symptom 2: "loss of interest and enjoyment" q3 = Do you feel like you are not interested in anything right now? q4 = Do you have less pleasure in doing things you usually enjoy? ICD-10 symptom 3: "increased fatigability" q5 = Do you currently have considerably less energy? q6 = Are your everyday tasks making you very tired currently? ICD-10 symptom 4: "reduced concentration and attention" q11 = Is it hard for you to make decisions currently? q12 = Is it hard for you to concentrate currently? ICD-10 symptom 5: "reduced self-esteem and self-confidence" q7 = Is your self-confidence clearly lower than usual? q8 = Are you feeling up to your tasks? ICD-10 symptom 6: "ideas of guilt and unworthiness" q9 = Are you blaming yourself currently? q10 = Do you think you are worth less than others right now? ICD-10 symptom 7: "bleak and pessimistic views of the future" q46 = Are you thinking that you will be doing well in the future? q47 = Are you looking hopefully into the future? ICD-10 symptom 8: "ideas or acts of self-harm or suicide" q16 = Are you thinking about death more often than usual? ICD-10 symptom 9: "disturbed sleep" q13 = Did you sleep badly last night? ICD-10 symptom 10: "diminished appetite" q14 = Do you have less or no appetite today?