Depression is a mental disorder, the main symptoms of which are reduced - depressed, depressed, dreary, anxious, fearful or indifferent mood and a decrease or loss of the ability to enjoy. Depression can result from a side effect of many drugs - the so-called iatrogenic or pharmacogenic depression. Most often, such depression quickly goes away on its own or heals after the withdrawal of the corresponding drug. The cause of depression in some cases is the abuse of sedatives or hypnotics, alcohol, cocaine and other psychostimulants, opiates