Antidepressants are designed to do just what their name implies: reverse the feelings of depression that a person is suffering.
And, there are almost as many antidepressants on the market as there are people who are depressed.
A Brief Discussion of Depression
Depression can occur for physical reasons as well as those caused by emotional or mental distress. For example, depression can occur as a result of a person suffering from chronic pain. The pain does not necessarily have to be all that severe or even debilitating (making it extremely hard or impossible for a person to carry on even the easiest of tasks).
Pain that is between a 4 and 7 on a scale of 1 to 10 (this is how most health care professionals determine the amount of pain one is feeling) that is constant and only minimally relieved or relief lasts for only a few hours can cause a person to be as depressed. Chronic pain has a "wearing down" effect on a person's mind and body; both of which can cause depression.
Further, studies are revealing that some types of depression are caused by chemical imbalances in the brain. In this instance, it can be said that the propensity for depression is "hard wired" into a person's brain. Of course, as with other things of this nature, this does not mean that a person is destined to become depressed. However, many do, and the chemical imbalance is why.
Depression is, of course, also caused by traumatic experiences in a person's life, such as death, divorce, or catastrophic illness suffered either by the person or a family member. Sometimes, though, this type of depression can be short lived, especially if a chemical imbalance does not exist and because therapy and other things can help alleviate the symptoms.