Being depressed means feeling negative emotions more intensely and longer than others. This condition prevents a person from fulfilling family, professional and social obligations. Depression is considered “major” if it significantly interferes with normal functioning and lasts more than two weeks. It is seasonal if it always occurs at the same time during the year, often at the beginning of winter. It is postnatal in women if it occurs within six months of delivery. Bipolar disorders, meanwhile, manifest themselves as depressive episodes interspersed with energized and elated behaviour (manic episodes).
Symptoms of depression include fatigue, lack of energy (or severe agitation in bipolar individuals), insomnia or hypersomnia, changes in appetite, decreased libido and the onset of discomforts such as headaches, backaches or stomach aches. In addition, there are psychological symptoms such as great sadness, loss of interest in one’s usual activities, lower self-esteem accompanied by feelings of guilt or failure, difficulty concentrating and making decisions, and, in many cases, suicidal thoughts. There is no laboratory test that can diagnose depression.