Antidepressant medications are widely used in treating psychiatric and neurologic disorders. Most of these medications are believed to work by slowing the removal of certain chemicals, called neurotransmitters, from the brain. Serotonin and norepinephrine are the neurotransmitters most commonly targeted by these medications. Neurotransmitters are needed for normal brain function and are involved in the control of mood and in other responses and functions, such as eating, sleep, pain, and thinking.
Antidepressants help people with depression by making these natural chemicals more available to the brain. By restoring the brain's chemical balance, antidepressants help relieve the symptoms of depression.
In addition to their role in fighting depression, several have also been shown to be effective with other types of neurologically-based symptoms.
Types of Antidepressants
Commonly used tricyclic antidepressants:
- amitriptyline (Elavil®)
- desipramine (Norpramin®)
- imipramine (Tofranil®)
- nortriptyline (Pamelor®)
Tricyclic antidepressants have been in use since the 1960’s. While very effective in relieving the symptoms of depression, they tend to produce more side effects than the newer family of antidepressants known as the selective serotonin reuptake inhibitors (SSRIs).
Commonly used SSRI antidepressants:
- fluoxetine (Prozac®)
- sertraline (Zoloft®)
- fluvoxamine (Luvox®)
- paroxetine (Paxil®)
- citalopram (Celexa®)
- escitalopram (Lexapro®)
In the late 1990s, another group of medications, known as selective serotonin and norepinephrine reuptake inhibitors (SSRNIs) became available.
Commonly used SSRNI antidepressants:
- venlafaxine (Effexor® )
- nefazodone (Serzone®)
Two additional antidepressants that are chemically unrelated to the others:
- bupropion (Wellbutrin®)
- mirtazepine (Remeron®)
Antidepressants May Also Help to Control Other MS-Related Symptoms
Because some of the tricyclic agents have anticholinergic properties that can cause people to retain urine, they are sometimes used in low doses to help control bladder incontinence. They are also used to help manage certain types of pain. Some of the antidepressants (e.g., fluoxetine) may also be helpful in reducing MS-related fatigue. Amitriptyline, desipramine, and fluoxetine have been shown in small clinical studies to help alleviate the uncontrollable laughing or crying (known as pseudobulbar affect) that is occasionally seen in people with MS.
The most common side effects of the tricyclic antidepressants include dry mouth, constipation, urinary retention (which can be beneficial for some people with MS-related frequency and urgency), sexual problems, blurred vision, dizziness, drowsiness, and increased heart rate.
The most common side effects of the newer antidepressants include sexual problems, headache, nausea, insomnia, jittery feelings.