Antidepressants are medications commonly prescribed to treat major depressive disorder and other types of clinical depression. They can also help manage depressive symptoms associated with other mental health conditions, such as PTSD or personality disorders. Beyond treating depression, antidepressants are often prescribed for conditions like anxiety disorders, chronic pain, and eating disorders.
Major Classes of Antidepressant MedicationsAntidepressants are categorized into several main groups:
- Selective serotonin reuptake inhibitors (SSRIs)
- Tricyclic antidepressants (TCAs)
- Monoamine oxidase inhibitors (MAOIs)
- Atypical antidepressants
Selective Serotonin Reuptake Inhibitors (SSRIs)SSRIs are among the newer and most widely prescribed antidepressants today. They work primarily by inhibiting the reabsorption (reuptake) of serotonin in the brain, increasing its availability. Elevated serotonin levels are believed to help relieve symptoms of depression.
Common SSRIs include:
- Prozac
- Paxil
- Zoloft
- Lexapro
- Celexa
- Luvox
While SSRIs typically have fewer severe side effects compared to older antidepressants, they can still cause side effects, such as:
- Anxiety or restlessness
- Nausea
- Decreased sexual interest
- Fatigue or drowsiness
- Sleep difficulties (insomnia)
- Dizziness
- Weight fluctuations (gain or loss)
- Dry mouth
- Digestive issues (diarrhea or constipation)
- Sweating
- Headaches
In some cases, SSRIs may increase the risk of suicidal thoughts, particularly among younger patients. They might also cause agitation, hostility, or increased risk of falls and bone fractures in older adults.
Tricyclic Antidepressants (TCAs)Tricyclic antidepressants are older medications with a broader mechanism of action compared to SSRIs. They were initially developed to provide a safer alternative to MAOIs, which have severe side effects.
TCAs increase the levels of neurotransmitters like serotonin and norepinephrine by blocking their reabsorption. Some TCAs also affect dopamine levels.
Common tricyclic antidepressants include:
- Elavil
- Anafranil
- Pamelor
- Norpramin
- Tofranil
Although TCAs are generally as effective as SSRIs in relieving depression, their side effects are often more severe. These can include:
- Irregular heartbeat or increased heart rate
- Constipation
- Confusion and disorientation
- Nausea
- Difficulty urinating
- Dizziness and impaired balance
- Dry mouth
- Vision disturbances
- Decreased sexual interest
- Weight gain
Due to these side effects, doctors often prefer SSRIs over TCAs.
Monoamine Oxidase Inhibitors (MAOIs)MAOIs are the oldest type of antidepressant medications. They work by blocking the enzyme monoamine oxidase, which breaks down neurotransmitters in the brain, thereby elevating neurotransmitter levels to help ease depressive symptoms. Due to their significant side effects and dietary restrictions, MAOIs are not typically the first treatment choice.
Commonly prescribed MAOIs include:
- Nardil
- Parnate
- Emsam
- Marplan
MAOIs can dangerously interact with foods, drinks, or medications containing the amino acid tyramine, potentially causing extremely high blood pressure, stroke, or heart attacks. Patients on MAOIs must carefully monitor their diets and medications.
Other side effects of MAOIs may include:
- Dizziness
- Sleep issues (insomnia)
- Weight gain
- Headaches
- Drowsiness
- Sexual dysfunction