Depression is the most common form of mental health problem. Most estimates are that twenty percent of people in the US are depressed, with the majority not getting any sort of treatment. Those people with depression who do get treatment usually do so in the forms of psychotherapy, some type of pharmaceutical prescription, or a combination of both. The pharmaceutical types most often prescribed for depression are, naturally enough, in the antidepressant class.

Antidepressants have been in use since the 1950's. The method for antidepressants is to alter the brain chemistry in some specific way, often to maintain levels of a particular chemical. The SSRI antidepressants for example are designed to keep levels of the brain chemical serotonin at certain levels, the thought being that reduced levels of serotonin lead to depression among other dysfunctions. SSRI is shorthand for Selective Serotonin Reuptake Inhibitor. The most well known of the SSRI's without question is Prozac.

Prozac became commercially available in Europe starting 1986 but work on the drug actually started in the 1970's. Contrary to what may be popular opinion, Prozac was not the first SSRI antidepressant but it was the most commercially successful of the initial SSRI's. This was certainly helped by the fact that the first SSRI antidepressant, zimelidine, was banned because it presented serious side effects. Before Prozac came along tricyclic antidepressants were most frequently prescribed for depression, and Prozac was marketed as a drug form dramatically different from the tricyclics.

Specifically, Prozac was said to be more precise in the way it worked and to present fewer side effects than the tricyclic antidepressants. The tricyclic antidepressants had a reputation for having troublesome side effects, including sexual functioning problems, rapid heart beat, and constipation. Though Prozac may have had fewer side effects than the tricyclics, Prozac was not an entirely clean drug when it came to carryover side effects: sexual dysfunction was also an effect seen during Prozac usage. Side effects from using Prozac however mostly were accepted to decrease as usage went on.

Whether Prozac was a miracle drug or not is certainly up for debate, but it did prove to be enormously profitable. There were literally millions of prescriptions written for Prozac, and the drug grossed billions of dollars before its patent expired. There are now a new generation of SSRI's on the market, and similar to Prozac they've proven to be widely prescribed and extremely popular. This gives credibility to the notion that the SSRI's may be the most effective type of antidepressant currently available.