Psychiatric Disorders and Pain

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The association between psychiatric disorders, most notably depression and anxiety, and pain is well established. However, mental health professionals, and especially psychiatrists, are still often excluded from treating patients with pain as many of our non-psychiatrist physician colleagues still often believe that there is little for them to do in the care of patients with pain unless it is clearly secondary to a psychiatric disorder. The results of two new studies highlight the importance of addressing mental health problems in patients with pain.

Total knee arthroplasty

The first study examined the effects of MDD on the outcomes for 260 patients who underwent total knee arthroplasty (TKA).¹ Patients completed baseline measures before the surgery that included the Patient Health Questionnaire to evaluate the presence of MDD and others to evaluate pain, level of functioning, and overall quality of life. The testing was repeated at a year following the surgery.

The patients were divided into four groups:

1) Those who didn’t suffer from MDD either at baseline or follow-up

2) Those who suffered MDD at baseline but not at follow-up

3) Those who didn’t suffer MDD at baseline but did at follow-up

4) Those who suffered MDD both at baseline and follow-up

At baseline there were no significant differences between the groups with regard to knee function. However, there were significant differences between them at one-year follow-up. Patient with MDD at both baseline and follow-up were found to have significantly less net improvement than patients in the other three groups. Patients who did not have MDD at baseline but did at follow-up also had less improvement than patients who never had MDD or those with MDD that had resolved by follow-up. Patients in the latter two groups had similar levels of improvement.

Visser and colleagues conclude that patients with MDD can still benefit from TKA. They emphasize that the presence of the psychiatric disorder is not a contraindication to the surgery, but it is important to at least begin to treat symptoms before patients undergo TKA. Moreover, it is important to monitor the mental health of patients who have undergone the surgery to determine whether depression is developing and needs to be treated. Also noted was the difficulty in determining whether the psychiatric disorder caused the reduction in benefits from the surgery or if the reason for continuing or new-onset depression was the lower level of improvement following the surgery.

Chronic low back pain

The second study comprised 284 patients with chronic low back pain (CLBP) with or without radiculopathy who were evaluated on their first visit to chronic pain clinics in Portugal.² The instruments used to evaluate patients included the Hospital Anxiety and Depression Scale (HADS), Brief Pain Inventory, and the Shortened Treatment Outcomes in Pain Survey. The latter two were again used at one-year follow-up to gauge the levels of pain and physical functioning.

During the year, the patients underwent what was described as “the usual multidisciplinary approach” to CLBP. Although the article does not include what was meant by this, it notes that among the services provided by the clinics were “general medical therapy, invasive approaches, physical therapy, and psychological assessment and/or cognitive behavioral therapy.”

At baseline, 51.4% of patients had depression and anxiety symptoms on the HADS while 21.5% had only anxiety, 6.7% only depression, and 20.4% neither. Study findings indicate that patients who suffered from both depression and anxiety symptoms at baseline had significantly worse outcomes with pain severity and disability at the one-year follow-up. The presence of either depression or anxiety alone at baseline also affected both of these measures but at a lesser level.

The researchers concluded that depression and anxiety symptoms at the onset of treatment of CLBP were predictive of treatment outcomes even at the pain clinics where it was expected that psychological issues would be addressed.

Conclusion

Both studies highlight the potentially significant impact the presence of psychiatric disorders and/or their symptoms can have on response to treatments for chronic pain. In patients with chronic pain, the presence of depression or anxiety is often discounted as being secondary to the pain and therefore expected to resolve once the pain improves. Furthermore, because of this, once treatments for the pain are instituted, the psychiatric disorders may be ignored.

Patients with CLBP may be expected to be offered some psychologically based treatments at a pain clinic, but that is not always guaranteed. Moreover, it is much less likely that someone undergoing a TKA would be offered similar services. Even if that person was in treatment for MDD, it is quite possible that the issue of pain may not come up during treatment because patients and psychiatrists may think that knee pain and the response to surgery may have little connection with one’s mental state. Even if MDD is identified prior to surgery, it may be overlooked as a possible factor in the level of a patient’s benefits as a result of the TKA.

These studies demonstrate that for many patients with chronic pain conditions and even those who undergo appropriate surgical therapies such as TKAs, the assessment of mental health at the onset and throughout treatment is of vital importance. Without the active involvement of mental health professionals including psychiatrists in the care of patients with pain, the effectiveness of treatment may be markedly reduced.

Disclosures:

Dr King is in private practice in Philadelphia.

References:

1. Visser MA, Howard KJ, Elli HB. The influence of major depressive disorder at both the preoperative and postoperative evaluations for total knee arthroplasty outcomes. Pain Medicine. 2019;20:826-833.

2. Oliveira DS, Mendonça LVF, Sampaio RSM, et al. The impact of anxiety and depression on the outcomes of chronic low back pain multidisciplinary pain management: a multicenter prospective cohort study in pain clinics with one-year follow-up. Pain Medicine. 2019;20:736-746.