Quitting smoking can lead to depression, but for people who have no history of depression, quitting smoking is more likely to cause depressive symptoms than depression. In other words, the depressive symptoms may be relieved over time, and most of them do not need medication. Why is quitting smoking depressed? In fact, it is not only quitting smoking, but also depressive symptoms will occur during the process of quitting many drugs, because most drug addiction involves reward pathways in the brain. The main addictive substance of tobacco is nicotine. Nicotine can combine with specific receptors, increase the amount of neurotransmitters, make neurons in reward centers in the brain secrete more dopamine, produce happiness and relaxation, and eventually lead to addiction. Read More …