How many times have you had a patient come in for a check-up voicing vague symptoms of pain like headaches, chronic joint or back pain, or muscle fatigue? Pain is more than just a somatic symptom — it is often a leading and often missed indicator of depression. Most patients with depression visit their primary care physician (PCP) before seeking mental healthcare. Unfortunately, these days, this clinical scenario has likely happened to you too many times to count.
The pain-depression dyad. Half of primary care visits are for somatic symptoms associated with depression or anxiety — it’s no wonder why 79% of antidepressants are prescribed by PCPs. It’s not always obvious when symptoms of pain stem from an underlying mental health condition. However, one should suspect depression may be an issue whenever a patient voices symptoms of pain — roughly 75% of primary care patients with depression report suffering some sort of physical pain.
As early as the 1970s, researchers found that pain and depression share the same neuromodulatory pathways. The brain normally moderates painful physical stimuli with serotonin and norepinephrine. Thus, when conditions like depression abnormally affect one’s ability to regulate these neurotransmitters, one can easily start experience symptoms of pain. Conversely, it comes as no surprise that targeting serotonergic and noradrenergic levels with reuptake inhibitors results in symptom relief of pain in addition to treating depression.
Additional studies have found that pain and depression share very similar pathologic findings and biological marker signatures from altered neuromodulation, pro-inflammatory cytokines, abnormal melatonin levels, neurotransmitter disturbances, increased oxidative stress, and stress susceptibility. It’s likely that these shared factors in pain sensitivity, stress response, and mood regulation can trigger and exacerbate pain symptoms when someone is also experiencing depression.
Antidepressants and pain. Some widely prescribed antidepressants are serotonin-norepinephrine reuptake inhibitors (SNRIs) (e.g., venlafaxine, duloxetine). By resetting serotonin and norepinephrine levels within the brain, SNRIs are popular as they are known to be effective for both pain and depression.
An analysis of 31 randomized clinical studies found venlafaxine, as a dual-action antidepressant, to be most effective for eliminating pain symptoms of depression. It was shown to be superior to SSRI antidepressants in leading to full remission of somatic pain symptoms. While tricyclic antidepressants are the most researched treatment for pain and reliably mitigate the symptoms, they can have significant complications (weight gain, hypotension, cardiovascular effects) — venlafaxine has far fewer side effects. Bupropion, also a dual-action antidepressant, is the only antidepressant approved by the FDA for treatment of neuropathic pain — it too can reduce symptoms of pain in depression patients.
How can you recognize pain as a symptom of depression in your patients? The most efficient way to recognize when somatic pain symptoms are related to depression is by conducting a straightforward screening. The U.S. Preventive Services Task Force has officially recommended depression screening for over a decade: It’s a critical first step for early intervention, and it’s covered by private insurance and Medicare, so you can bill for it.
Start with the clinically validated, two-question PHQ-2 as a first step. Though your patients may not recognize or self-report depression, studies have shown people will answer questions about depression symptoms when asked. If a patient screens positive, you can then use the PHQ-9 to evaluate if they meet the criteria for clinical depression. Screening may take a few minutes in your appointments — but it will save your practice significant time in the long run.
You don’t have to do this alone — connect patients to a mental health provider. Some patients may respond best to psychotherapy in combination with antidepressants, while others may need therapy alone. Connecting a patient to a mental health provider can help you to determine the best treatment course for that person’s individual needs. Working together, you can efficiently and effectively treat depression, reduce repeat primary care visits, and improve patients’ overall health.