Chronic pain is a complex medical condition that affects around 20 percent of the world’s population.

According to the American Academy of Pain Medicine, it is the most common cause of long-term disability in the United States, with estimated costs exceeding $560-$635 billion annually in the US alone. Antidepressants, typically used to treat depression, have been found to be effective in relieving chronic pain. This article will provide a comprehensive review of the use of antidepressants for chronic pain.

: Types of Antidepressants

Antidepressants are classified into different categories based on their mechanism of action. The most commonly used ones for chronic pain include:.

Tricyclic antidepressants (TCAs)
Selective serotonin reuptake inhibitors (SSRIs)
Serotonin-norepinephrine reuptake inhibitors (SNRIs)
Monoamine oxidase inhibitors (MAOIs)
Norepinephrine dopamine reuptake inhibitors (NDRIs)

: Tricyclic Antidepressants (TCAs)

TCAs are one of the oldest types of antidepressants and have been used for the treatment of chronic pain since the 1970s.

They work by blocking the reuptake of serotonin and norepinephrine, which increases the level of these neurotransmitters in the brain. This results in a reduction in pain perception. TCAs commonly used for chronic pain include:.

Amitriptyline
Nortriptyline
Imipramine

: Selective Serotonin Reuptake Inhibitors (SSRIs)

SSRIs work by increasing the level of serotonin in the brain. They are commonly used to treat depression but have also been found to be effective for chronic pain. SSRIs that are commonly used for chronic pain include:.

Fluoxetine
Paroxetine
Sertraline

: Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)

SNRIs are newer antidepressants that work by blocking the reuptake of both serotonin and norepinephrine. They are commonly used for the treatment of depression, anxiety, and chronic pain. SNRIs that are commonly used for chronic pain include:.

Duloxetine
Venlafaxine

: Monoamine Oxidase Inhibitors (MAOIs)

MAOIs work by increasing the level of serotonin, norepinephrine, and dopamine in the brain. They are not commonly used for chronic pain due to their potential side effects and interactions with other medications.

MAOIs that are commonly used for chronic pain include:.

Phenelzine
Tranylcypromine

: Norepinephrine Dopamine Reuptake Inhibitors (NDRIs)

NDRIs work by blocking the reuptake of both norepinephrine and dopamine. They are not commonly used for chronic pain due to their potential side effects and interactions with other medications. NDRI that is commonly used for chronic pain includes:.

Bupropion

: Effectiveness of Antidepressants for Chronic Pain

Antidepressants have been found to be effective in relieving chronic pain. Studies have shown that they can reduce pain intensity, improve physical functioning, and improve quality of life.

Antidepressants are most effective for chronic pain that is neuropathic in origin, such as diabetic neuropathy, postherpetic neuralgia, and complex regional pain syndrome (CRPS). They may also be effective for chronic pain that is non-neuropathic in origin, such as fibromyalgia, chronic low back pain, and osteoarthritis.

: Side Effects of Antidepressants for Chronic Pain

Antidepressants are generally safe when used as prescribed. However, they do have potential side effects. Common side effects include dry mouth, constipation, blurred vision, and drowsiness.

TCAs are more likely to cause side effects than other antidepressants. Some antidepressants may also interact with other medications, so it is important to inform your doctor of all medications you are taking.

: Conclusion

Antidepressants have been found to be effective in relieving chronic pain, particularly neuropathic pain. TCAs, SSRIs, SNRIs, MAOIs, and NDRIs are the main types of antidepressants used for chronic pain.

While they are generally safe when used as prescribed, they may have potential side effects and interactions with other medications. As with any medication, it is important to consult with your doctor before starting any antidepressant medication for chronic pain.