Doctors prescribe medications called antidepressants to help relieve symptoms of clinical depression and related conditions, such as social anxiety disorder, seasonal affective disorder, and obsessive-compulsive disorder (OCD). The purpose of these medications is to adjust chemical imbalances in the brain that may account for shifts in behavior and mood. 

Though developed in the 1950s, the use of antidepressants has become increasingly more common over the last 20 years. Today, common antidepressants fall into one of five main categories.

Serotonin and Noradrenaline Reuptake Inhibitors (SNRIs)

Serotonin and noradrenaline reuptake inhibitors are one of the two most commonly prescribed antidepressants. SNRIs treat mood disorders and major depressive disorder (MDD), as well as a variety of other conditions related to a chemical imbalance such as:

  • Anxiety disorders including social anxiety

  • Attention deficit hyperactivity disorder (ADHD)

  • Obsessive-compulsive disorder (OCD)

Likewise, SNRIs can be used to treat chronic pain disorders such as fibromyalgia and neuropathic pain. Once metabolized by your body, SNRIs impact levels of serotonin and norepinephrine. These are two of your brain’s neurotransmitters that play a large role in helping to stabilize mood.

Common medications that are SNRIs include:

  • Desvenlafaxine, such as Pristiq

  • Venlafaxine, such as Effexor

  • Duloxetine, such as Cymbalta

Selective Serotonin Reuptake Inhibitors (SSRIs) 

Selective serotonin reuptake inhibitors are also mostly used in depression treatment. SSRIs work to block the reuptake of serotonin, which allows for a higher concentration of the neurotransmitter to remain in the body. 

An increase in serotonin makes it easier for neurotransmitters to send and receive messages, which can result in stable and more positive moods. SSRIs  “selective” due to their ability to affect only serotonin and not other neurotransmitters. 

Common medications that are SSRIs include:

  • Fluoxetine, such as Prozac or Sarafem

  • Sertraline, such as Zoloft 

  • Citalopram, such as Celexa

  • Paroxetine, such as Paxil

  • Escitalopram, such as Lexapro

  • Fluvoxamine, such as Luvox

A Note About SNRIs and SSRIs

SNRI and SSRI medications are the most commonly prescribed antidepressants, but these drugs are not without side effects, including:

  • Nausea

  • Tremors

  • Dry mouth

  • Weight loss 

  • Trouble sleeping

  • Constipation or diarrhea

  • Anxiety and agitation 

  • Headache and dizziness

  • Abnormal thinking

  • Sexual dysfunction

  • Low sodium

  • Low blood sugar, or hypoglycemia

Note that those under the age of 18 may want to proceed with caution. Those who use SSRIs and SNRIs, especially young people, may experience thoughts of suicide when first beginning the medication. All antidepressants that involve this risk have a black box warning, as required by the Food and Drug Administration (FDA). 

Tricyclic Antidepressants (TCAs)

Tricyclic antidepressants or TCAs treat depression and anxiety disorders as well as chronic pain and fibromyalgia. The name comes from their chemical structure, which features three cylindrical rings. 

Tricyclic antidepressants often lack the cognitive side effects of SSRIs and SNRIs, though they do feature physical side effects, including:

  • Trouble sleeping 

  • Constipation

  • Nausea and vomiting

  • Abdominal cramps

  • Weight loss

  • Sexual dysfunction

  • Irregular heartbeat or arrhythmia

  • Seizures

Common medications that are SSRIs include:

  • Amoxapine-clomipramine, such as Anafranil

  • Doxepin, such as Sinequan

  • Amitriptyline, such as Elavil

  • Nortriptyline, such as Pamelor

  • Trimipramine, such as Surmontil

  • Desipramine, such as Norpramin

  • Imipramine, such as Tofranil 

  • Protriptyline, such as Vivactil

Monoamine Oxidase Inhibitors (MAOIs) 

Monoamine oxidase inhibitors, or MAOIs, are one of the oldest types of antidepressants. They suppress the action of monoamine oxidase, a brain enzyme that breaks down helpful neurotransmitters like serotonin, allowing more to circulate—thus stabilizing moods and decreasing anxiety. 

Before SSRIs and SNRIs came on the market, MAOIs were the go-to antidepressant. Today, they are typically only prescribed if a previous inhibitor has not worked. MAOIs may interact with some foods and medication, leading to side effects like:

  • Nausea

  • Seizures

  • Blurred vision

  • Weight loss or weight gain

  • Diarrhea and constipation

  • Insomnia or drowsiness

  • Headache and dizziness

  • Fainting or feeling faint when standing up

Common medications that are MAOIs include:

  • Isocarboxazid, such as Marplan

  • Tranylcypromine, such as Parnate

  • Phenelzine, such as Nardil

  • Selegiline, such as EMSAM or Eldepryl

Noradrenaline and Specific Serotonergic Antidepressants (NASSAs) 

Noradrenaline and specific serotonergic antidepressants, abbreviated as NASSA, are used to treat depressive, anxiety, and personality disorders. Much like the above medications, NASSAs target neurotransmitters such as serotonin to balance mood. NASSAs generally appear to have slightly fewer side effects, though there may still be some. 

Common side effects of NASSAs include:

  • Dry mouth

  • Weight gain

  • Constipation

  • Blurred vision 

  • Drowsiness and dizziness

Common medications that are MAOIs include:

  • Mianserin, such as Tolvon

  • Mirtazapine, such as Remeron, Avanza, or Zispin

If you’re curious about antidepressants, speak with your Confidant provider to find out what medication may best suit your needs.