Abstract: The present invention relates to a method of diagnosing, tracking, and rating depressive symptoms in order to predict responses to specific treatments and guide further adjustments and interventions to treatments. The present invention permits rapid and meaningful depressive symptom severity ratings even when conventional or verbal symptom descriptions are difficult or impossible. The present invention further provides a means for detecting and quantifying intense emotional pain, including depression subtypes and major depressions with psychotic features. The present invention also provides a means of quantitative comparisons for the results of successive treatment trials. The present invention covers the whole range of depression symptom diagnosis and requires no literacy or minimal mental capacities from the patients. Furthermore, the present invention minimizes bias in order to avoid over or under diagnosis and treatments.