The class of drugs known as antidepressants is used primarily to treat clinical depression (also called major depression).
See the following for causes, symptoms, diagnosis and treatment of depression:
The goal of antidepressants is to elevate the mood of patients who are clinically depressed by chemically affecting neurotransmitters in the brain. In addition to treatment for depression, certain antidepressants are sometimes prescribed as a primary treatment for chronic pain, anxiety disorders, and/or sleep disorders or insomnia.
The main classes of antidepressants include:
Selective Serotonin Reuptake Inhibitors (SSRIs)
This represents a newer class of antidepressants and currently SSRI’s are the most commonly prescribed forms of antidepressants used to treat depression and closely related disorders such as chronic pain. SSRI’s are designed to keep serotonin, a neurotransmitter in the brain that affects mood, in the brain longer, which in turn can alleviate the symptoms of depression.
SSRI’s have relatively fewer side effects than other classes of antidepressants. Some of the side effects that can be caused by SSRIs include dry mouth, nausea, nervousness, insomnia, sexual problems and headache.
Examples of commonly prescribed SSRI’s include:
- Citalopram (e.g. brand name Celexa)
- Escitalopram (e.g. brand name Lexapro)
- Fluoxetine (e.g. brand name Prozac)
- Paroxetine (e.g. brand names Paxil, Pexeva)
- Sertraline (e.g. brand name Zoloft)
This is an older class of antidepressant drug that typically has significant side effects, and therefore are used less often than SSRI’s to treat depression. Undesirable side effects from tricyclic antidepressants may include blurred vision, weight gain, sleepiness, and more. These types of antidepressant medications are sometimes prescribed in low doses for patients who need help sleeping or for treatment of chronic pain. Tricyclic antidepressants taken as sleep-aids are not addictive and do not change a patient’s sleep cycles, and therefore may be taken on a long-term basis. Initially, most patients feel groggy the morning after taking a tricyclic, but this "hangover" effect typically goes away quickly. Tricyclic medications also seem to diminish pain if taken on a regular basis, although the mechanism for this pain relieving effect is not known.
Side effects caused by tricyclic antidepressants these medicines include: dry mouth, blurred vision, constipation, difficulty urinating, worsening of glaucoma, impaired thinking and tiredness, as well as possibly affecting one’s blood pressure and heart rate.
Types of tricyclic antidepressants prescribed include:
- Amitriptyline (e.g. brand name Amitril, Elavil)
- Desipramine (e.g. brand name Norpramin)
- Imipramine (e.g. brand name Tofranil)
- Nortriptyline (e.g. brand name Aventyl, Pamelor)
Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs)
Some common side effects caused by these medicines include nausea and loss of appetite, anxiety and nervousness, headache, insomnia and tiredness. Dry mouth, constipation, weight loss, sexual problems, increased heart rate and increased cholesterol levels can also occur.
Types of SNRI antidepressants sometimes prescribed include:
- Venlafaxine (e.g. brand name Effexor)
- Duloxetine (e.g. brand name Cymbalta)
Norepinephrine and Dopamine Reuptake Inhibitors (NDRIs)
Side effects for people taking NDRIs may include: agitation, nausea, headache, loss of appetite, insomnia, and risk of increased blood pressure.
- Bupropion (e.g. brand name Wellbutrin, Wellbutrin XR, Zyban)
Combined Reuptake Inhibitors and Receptor Blockers
Side effects of this type of antidepressants may include: drowsiness, dry mouth, nausea and/or dizziness. This type of antidepressant should not be taken by anyone with liver problems, and there are a number of other potential side effects and complications that should be discussed with the treating physician.
- Trazodone (e.g. brand name Desyrel)
- Nefazodone (e.g. brand name Serzone)
- Maprotiline (no brand name; generic form only)
- Mirtazpine (e.g. brand name Remeron)
Monoamine Oxidase Inhibitors (MAO Inhibitors, or MAOI’s)
This is an older class of antidepressant drug and not usually used for treatment of depression or other disorders anymore. They may be used selectively to treat certain patients with certain types of depression.
These antidepressants require dietary restrictions and include significant possible side effects, such as drowsiness, dizziness, headaches, weakness, trembling, high blood pressure, and more. Taking an MAOI antidepressant while taking another form of antidepressant or certain other medications (including some over-the-counter medicines) can cause significant harm. Patients taking an MAOI should clearly understand what food, beverages and medications to avoid before taking the drug.
Examples of MAO inhibitors include:
- Isocarboxazid (e.g. brand name Marplan)
- Phenelzine (e.g. brand name Nardil)
- Tranlcypromine (e.g. brand name Parnate)
Antidepressants also Used to Treat Pain, Sleep Disorders, Anxiety
In addition to treatment of depression, antidepressant drugs are also sometimes used to treat additional health problems (whether they occur alone or in combination with depression), such as:
- Anxiety disorders
- Chronic pain
- Sleep disorders
- Any combination of the above
Any form of chronic pain is known to cause depression, and depression makes it more difficult to deal with pain. Therefore, it is important for pain and depression to be treated simultaneously for the treatment to be successful.
Potential Risks, Side Effects
Antidepressants are often accompanied by a range of undesirable side effects and the efficacy of each type of antidepressant varies from patient to patient. Antidepressants may have serious (potentially fatal) drug interactions with certain other types of medications, so patients should have a careful discussion with their physician before taking antidepressants.