Antidepressant

Antidepressants are drugs used for the treatment of major depressive disorder and of other conditions, including some anxiety disorders, some chronic pain conditions (off-label use), and to help manage some addictions. Common side-effects of antidepressants include dry mouth, weight gain, dizziness, headaches, and sexual dysfunction. Most types of antidepressants are typically safe to take, but may cause increased thoughts of suicide when taken by children, adolescents, and young adults. A discontinuation syndrome can occur after stopping any antidepressant which resembles recurrent depression. There is some debate in the medical community about how much of the observed effects of antidepressants can be attributed to the placebo effect, but the bulk of the scientific research show that most antidepressants in broad clinical use are more effective than placebo. Between 30% and 50% of individuals treated with a given antidepressant do not show a response. In clinical studies, approximately one-third of patients achieve a full remission, one-third experience a response and one-third are nonresponders. Partial remission is characterized by the presence of poorly defined residual symptoms. These symptoms typically include depressed mood, anxiety, sleep disturbance, fatigue and diminished interest or pleasure. It is currently unclear which factors predict partial remission. However, it is clear that residual symptoms are powerful predictors of relapse, with relapse rates 3–6 times higher in patients with residual symptoms than in those who experience full remission. In addition, antidepressant drugs tend to lose efficacy over the course of treatment. According to data from the Centers for Disease Control and Prevention, less than one-third of Americans taking one antidepressant medication have seen a mental health professional in the previous year. A number of strategies are used in clinical practice to try to overcome these limits and variations. They include switching medication, augmentation, and combination. The American Psychiatric Association 2000 Practice Guideline advises that where no response is achieved following six to eight weeks of treatment with an antidepressant, to switch to an antidepressant in the same class, then to a different class of antidepressant. A 2006 meta-analysis review found wide variation in the findings of prior studies; for patients who had failed to respond to an SSRI antidepressant, between 12% and 86% showed a response to a new drug. However, the more antidepressants an individual had already tried, the less likely they were to benefit from a new antidepressant trial. However, a later meta-analysis found no difference between switching to a new drug and staying on the old medication; although 34% of treatment resistant patients responded when switched to the new drug, 40% responded without being switched. For a partial response, the American Psychiatric Association guidelines suggest augmentation, or adding a drug from a different class. These include lithium and thyroid augmentation, dopamine agonists, sex steroids, NRIs, glucocorticoid-specific agents, or the newer anticonvulsants. A combination strategy involves adding another antidepressant, usually from a different class so as to have effect on other mechanisms. Although this may be used in clinical practice, there is little evidence for the relative efficacy or adverse effects of this strategy. Other tests recently conducted include the use of psychostimulants as an augmentation therapy. Several studies have shown the efficacy of combining modafinil to treatment-resistant patients. It has been used to help combat SSRI-associated fatigue. The therapeutic effects of antidepressants typically do not continue once the course of medication ends. This results in a high rate of relapse. A 2003 meta-analysis of 31 placebo-controlled antidepressant trials, mostly limited to studies covering a period of one year, found that 18% of patients who had responded to an antidepressant relapsed while still taking it, compared to 41% whose antidepressant was switched for a placebo. A gradual loss of therapeutic benefit occurs in a minority of people during the course of treatment. A strategy involving the use of pharmacotherapy in the treatment of the acute episode, followed by psychotherapy in its residual phase, has been suggested by some studies. Antidepressants are used to treat major depressive disorder and of other conditions, including some anxiety disorders, some chronic pain conditions, and to help manage some addictions. Antidepressants are often used in combinations with one another.