Depression was always considered as a mood disorder characterised by feelings of sadness, low self-esteem and aversion to activity that can affect a person’s thoughts, behavior, feelings and sense of well-being. While clinical depression was a more severe form of depression marked by persistent low mood throughout the day. However, a team of researchers from the University of Granada (UGR) have proved scientifically for the first time that depression is more than a mental disorder. It causes important alterations of the oxidative stress, and hence should be considered as a systemic disease (something that affects a number of organs and tissues), since it affects the whole organism. Their work was published in the renowned Journal of Clinical Psychiatry.