A mental health disorder characterized by persistently depressed mood or loss of interest in activities, causing significant impairment in daily life.
Self-Report Study: A type of survey, questionnaire, or poll in which respondents read the question and select a response by themselves without researcher interference.
Psychometric Test: A psychological test that is designed to measure one's mental capabilities and behavioral style; these tests are intended to measure the innate aspects of an individual such as intellectual potential and personality traits.