Note from Brianna: Hey guys! If you have struggled with chronic pain, you have most likely had a doctor prescribe you an anti-depressant. This is confusing to a lot of people because it feels like the doctor is trying to treat you for depression instead of pain. This can be really frustrating. So here is an explanation for why doctors prescribe antidepressants for chronic pain.

Something I want you guys to understand as you read this blog post is that doctors prescribe treatments that they have seen work on patients. If they are prescribing you an antidepressant instead of an opioid, that means the doctor has seen that antidepressant work on patients with chronic pain before. 

Try to keep in mind that different antidepressants work on different people with different conditions and it takes time to figure out which one may be best for you. I went through several antidepressants before I found the ones that worked best for me and it took over a year to figure it out. 

• There is a lot of debate on the use of antidepressants for the treatment of chronic pain (Bettinger, 2023). There are lots of studies showing that antidepressants are effective for pain relief and other studies showing that antidepressants have a minimal impact on chronic pain conditions. Ultimately, it varies for each person.

• You do not have to have depression for your doctor to prescribe an antidepressant for chronic pain (Solan, 2023)

• They work by acting on chemicals in the brain that assist with pain relief such as serotonin and norepinephrine (Solan, 2023)

• The most commonly prescribed antidepressants are tricyclic antidepressants (especially amitriptyline) (Solan, 2023). 

• Serotonin-norepinephrine reuptake inhibitors (SNRIs) such as duloxetine (cymbalta) have been proven to reduce pain in conditions such as back pain, knee osteoarthritis, postoperative pain, fibromyalgia, and nerve pain (Solan, 2023).

Depression and Chronic Pain

• Depression can make chronic pain worse and last even longer (Bonilla-Jaime et al., 2022)

• Pain makes you feel depressed and being depressed makes your pain feel worse. It’s an endless cycle (Bonilla-Jaime et al., 2022)

• Having chronic pain increases your chances of developing major depression or anxiety (Bonilla-Jaime et al., 2022)

• Two-thirds of people with chronic pain develop mental health problems (Bonilla-Jaime et al., 2022)

• People with chronic pain may feel so overwhelmed by their pain that they start thinking about harming themselves. It is estimated that 20% of people with chronic pain have thoughts about ending their own life (Bonilla-Jaime et al., 2022).

Antidepressants

• They don’t only help with emotional pain, but also physical pain. Antidepressants disrupt signals in the nervous system that cause pain

• Antidepressants all work differently from each other, but the majority of them alter the serotonin and norepinephrine levels within your brain.

• There are also voltage-gated sodium channels that control the flow of signals in your nerves. Antidepressants can block these channels and turn down the intensity of the pain (Bonilla-Jaime et al., 2022).

• Tricyclic antidepressants

• These include amitriptyline, clomipramine, desipramine, doxepin, imipramine, nortriptyline, protriptyline

• They interact with serotonin and norepinephrine and help the body produce more natural painkillers. They also calm down the messengers that send pain signals.

• Selective serotonin reuptake inhibitors

• These include fluoxetine (prozac), citalopram (Celexa), escitalopram (Lexapro), fluvoxamine (Luvox), paroxetine (paxil), sertraline (zoloft), venlafaxine (effexor), and duloxetine (cymbalta).

• They are not as effective as tricyclic antidepressants, but they have been used to treat headaches and migraines (Bonilla-Jaime et al., 2022).

• They are not recommended as the first-line treatment for chronic pain.

• Serotonin norepinephrine reuptake inhibitors

• Duloxetine (cymbalta) has been used to effectively reduce pain in osteoarthritis, chronic low back pain, diabetic peripheral neuropathy, and fibromyalgia (Bonilla-Jaime et al., 2022)

Types of Pain

• Nociceptive Pain is pain provoked by damage to non-neural tissues. Examples include breaking a bone, twisting an ankle, getting a paper cut, appendicitis, abdominal cramps, etc.

• Studies have shown that fluoxetine can be beneficial for nociceptive pain.

• One study showed that when morphine is given with fluoxetine, there is an increase in pain reduction, a reduction in the development of tolerance to morphine, decreases the development of dependence and withdrawal syndrome, and there is an improvement in opioid-induced hyperalgesia (Bonilla-Jaime et al., 2022).

• Chronic inflammation can lead to pain. The release of proinflammatory mediators such as prostaglandins, cytokines, chemokines, proteases, neuropeptides, and growth factors all lead to an increase in inflammation and pain.

• The skin, joints, and intestines are most susceptible to chronic inflammation.

• Atopic dermatitis is a chronic inflammatory condition affecting the skin. It is usually resistant to antihistamines and steroids. Antidepressants such as amitriptyline, doxepin, paroxetine, fluvoxamine, sertraline, and mirtazapine have been effective in reducing the symptoms of atopic dermatitis.

• Neuropathic pain can be defined as pain caused by injury to the nervous system. Some examples include trigeminal neuralgia, carpal tunnel, occipital neuralgia, shingles, etc.

• This type of pain is characterized by a burning or electric sensation.

• Antidepressants can reduce neuropathic pain by as much as 50% (Bonilla-Jaime et al., 2022)

• Tricyclic antidepressants such as amitriptyline, nortriptyline, and desipramine are often first-line drugs for neuropathic pain conditions, headaches, gastrointestinal syndromes, fibromyalgia, pelvic pain, and insomnia. 

• Amitriptyline is known to be as effective as pregabalin, gabapentin, and duloxetine.

Specific Conditions

• Osteoarthritis

• A study of Japanese patients with osteoarthritis showed that duloxetine improved pain, physical, mental, and emotional health of patients (Bonilla-Jaime et al., 2022)

• Chronic low back pain

• Duloxetine was also proven to be effective for chronic low back pain reduction

• Gastrointestinal Disorders

• Antidepressants can have some positive effects on patients with gastrointestinal disorders, but there is not strong evidence suggesting that this happens consistently.

Bonilla-Jaime, H., Sánchez-Salcedo, J. A., Estevez-Cabrera, M. M., Molina-Jiménez, T., Cortes-Altamirano, J. L., & Alfaro-Rodríguez, A. (2022). Depression and Pain: Use of Antidepressants. Current neuropharmacology, 20(2), 384–402. https://doi.org/10.2174/1570159X19666210609161447

Solan, M. (2023, May 1). Which antidepressants are best for treating chronic pain?. Harvard Health. https://www.health.harvard.edu/pain/which-antidepressants-are-best-for-treating-chronic-pain