Drug Treatment Guidelines
Major Classes of Antidepressants and General Treatment Guidelines
Major classes of antidepressants include:
- Selective serotonin-reuptake inhibitors (SSRIs). These drugs have become the standard antidepressants. They target the brain chemical (neurotransmitter) serotonin. They can be effective and usually have moderate side effects.
- Other neurotransmitter inhibitors. These drugs target neurotransmitters other than or in addition to serotonin, such as norepinephrine. Many are proving to be effective in patients who do not respond to standard antidepressants or in specific patients, such as smokers who want to quit or patients with chronic pain.
- Tricyclic antidepressants (TCAs). These drugs are effective but can have severe adverse effects, particularly in older people.
- Monoamine oxidase inhibitors (MAOIs). These drugs include newer selective MAOIs. MAOIs are the most effective antidepressants for atypical depression, but have some severe side effects and require restrictive dietary rules and care to avoid drug interactions.
All of these drugs appear to work equally well, although they may vary in terms of side effects. Your doctor will select an antidepressant based on side effects, cost, and your personal preference.
Approach and Duration of Initial Treatment. The guidelines for the duration of an initial antidepressant regimen are generally:
- Patients should start at a low dose, which is increased over a period of 5 - 10 days.
- Patients should see their doctor every 1- 2 weeks until substantial improvement occurs. It may take 4 - 8 weeks before a patient experiences the effects of any antidepressant.
- Side effects usually diminish within 1 - 4 weeks. (Exceptions may be weight gain and sexual dysfunction.)
- If no improvement occurs within 6- 8 weeks of starting drug treatment, the doctor may either increase the dosage or switch to an alternative drug. More than 80% of patients respond to some antidepressant, although specific drugs are helpful for only about half of patients. This suggests that if one medication fails, another has a good chance of being helpful. In general, the fewer drug treatment strategies required, the better a patient's chances of recovering completely from depression. Patients who become symptom-free have the best chance for complete recovery compared to patients whose symptoms merely improve.
- In general, patients should continue taking antidepressants for at least 4 - 9 months after symptom relief to help prevent relapse. Patients who have had at least 2 episodes of depression may need to continue drug treatment for longer than 9 months. (Patients who improve within 2 weeks of taking medications may not require lengthy treatment.)
Review Date: 01/27/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.