Depression occurs when the brain is unable to produce sufficient chemical substances to keep the person in a normal state of mind. During this phase, the person is not able to use his or her willpower alone to get out of the state of depression. Negative thinking, lack of interest and inability to feel good are part and parcel of depressive disorders. Medicines help correct the neurochemical imbalance faster. Psychotherapy, in addition to medical therapy, can hasten the process of recovery.