Endometriosis affects around 1 in 10 women. It is a condition where endometrial-like cells, grow outside of the uterus not just limited to surrounding areas such as the ovaries, fallopian tubes and the bowels, but beyond to other organs and tissues including the lungs, brain and skin, although this is rarer. Endometrial-like deposits cause an inflammatory reaction within the body which can result in the formation of adhesions, pain and other symptoms such as cramping, fatigue and bowel symptoms. 64% of those with endometriosis report experiencing pelvic pain which can be extremely debilitating stopping people from being able to work, socialise and feel part of society.
In some cases, surgery helps reduce pain but in 20% of cases it does not and for some people, pain can return. In the broader pain research, the experience of physical pain is established to be the product of a combination of “biological” neurotransmission, called nociception, in addition to a wider psychological and social experience. It is therefore understood as a biopsychosocial experience, as perception, emotion and social context can influence the degree, duration and intensity of pain experiences.
In the context of endometriosis, less is known about the role of psychological and social factors. A clear social factor that has more recently gained some awareness, is the experience of dismissal, delayed and incorrect diagnoses. In the absence of adequate investigation and support, women are left to deal with symptoms on their own often at a significant psychological and physical burden.
My colleagues and I sought to explore the role of psychological and social factors in the experience of endometriosis [1]. We were specifically interested in health-related experiences i.e. pain, and physical functioning. To do this, we systematically collected all research papers looking at the association between psychological and social factors and pain or health-related quality of life.
In total, 27 studies involving 5,419 participants were collected. Key things we noted were that a lot of the research was cross-sectional, meaning that it could not accurately demonstrate the direction of the relationship between psychological experiences and physical outcomes as they were measured at the same time point. To get a better idea of this, more prospective research is needed to see whether one influences the other over time. The other glaring omission in studies to date is that there are no studies looking at the impact of social context and experiences on outcomes in endometriosis. Given that dismissal and disbelief are huge issues, it is surprising that no research has sought to quantify this as yet. We found a few studies assessing the association between being in a relationship and health-related quality of life in endometriosis. These studies suggested that being in a stable and supportive relationship positively impacted psychological wellbeing but had no impact on physical outcomes.
Endometriosis, pain and a person’s ability to live a fulfilling life
In the review, we were focused on physiological outcomes and the association with psychological and social factors. We wanted ideally to include papers that looked at physiological markers of disease severity including biomarkers, if available (e.g. inflammation, adhesions, etc) but there were no such studies. What we found instead was that studies reported on pain severity and “health-related quality of life” (HRQoL). Health-related quality of life is a multidimensional concept broadly assessing the extent to which a person perceives their health to impact on their functioning. Functioning is generally divided up into different constructs including physical functioning, social functioning and psychological/emotional or mental functioning. Overall, a measure of HRQoL is intended to measure how health impact on a person’s ability to live a fulfilling life.
Example items measuring physical function from a standard HRQoL include:
Have you had to cut down the amount of time you spent on work or other activities due to your physical health?
Have you accomplished less than you would like due to physical health
How much bodily pain have you had during the past 4 weeks? With options none, very mild, mild, moderate, severe and very severe.
Our results therefore focussed on these outcomes in endometriosis and conceptualising the link between them and psychological factors.
Mental health & physical outcomes in endometriosis
Six studies explored the association between depression and pain and depression and HRQoL. Interestingly, while 3 studies found that depression was associated with greater pain, 3 did not find this association. We discussed the fact that it may not be as simple as the more depressed you are, the worse your pain will be. We know from chronic pain literature that there are multiple other variables that will impact pain experience including protective factors like social support and the presence of exacerbating factors like a threatening social environment or lack of access to healthcare. Perhaps unsurprisingly, all studies looking at the relationship between depression and HRQoL found significant medium to large associations. This would indicate that the more depressed, the more negatively impacted by health people were and the more health issues interrupted their functioning.
Seven studies looked at the relationship between anxiety and pain. Six of these found that the worse anxiety, the worse pain (and/or vice versa as we cannot infer causality). Five studies explored anxiety and HRQoL and once again, all demonstrated significant medium to large effect sizes. That is to say, the more anxious, the more people felt their physical, social and emotional functioning was impaired by endometriosis. Stress was also associated with worse HRQoL including pain-specific domains and physical functioning.
Thought processes and pain in endometriosis
The experience of pain can set off a truckload of worries and fears as people commonly worry that the pain will not go away or will get worse. Researchers have developed measures for these thought processes which involve predicting ahead to a feared worst-case scenario. Unhelpfully (in my opinion) this measure has been termed “pain catastrophising”. Such measures have demonstrated that these fearful thought processes influence pain severity later down the line. This was also demonstrated in the context of endometriosis by one study included in the review. Two other studies measuring the role of these thought processes also found that there was a significant association with pain.
Clinically, this association makes sense. A previous blog post introduced the concept of neuroception: the neural communication of an experience being safe or threatening. If we add layers to this neural communication through our conscious thought processes, we communicate with the body that we are in more danger. The body’s go-to response to threat is often to mobilise, leading to hyperarousal of the nervous system, which can consequently impact on pain processing.
The review also found that ruminating and self-blame were associated with worse pain. Conversely, the perception of being able to cope and feeling acceptance was associated with better health-related quality of life.
Emotions, pain and ability to function in endometriosis
One study demonstrated that people who had more difficulties in describing emotions and feelings tended to have greater pelvic pain intensity and worse physical, social, emotional and mental functioning. Another study showed that those with difficulties regulating emotions also rated worse HRQoL.
Can personality characteristics affect pain in endometriosis?
Fewer studies assessed the role of personality. Of the two that did, one demonstrated that people who tended to be worried and sensitive to criticism had higher ratings of pelvic pain. In contrast, those who tended to be self-directed with the belief that they largely are able to solve their own problems and exert control had less pain. Taken with the findings of studies assessing cognitive processes, it seems that perceived control and views of one’s self may play an important role in buffering pain experience.
I have endometriosis, what should I make of this?
The review demonstrates a close relationship between physiological experiences such as pain and the ability to physically function and psychological experience. Although most studies cannot infer that psychological experience exacerbates physiological symptoms or functioning, there is some preliminary evidence that suggests this is worthwhile exploring. Symptoms in endometriosis can take a big toll on wellbeing. This is something that needs addressing whether it ultimately influences pain or not. Providing psychological support can help ameliorate the degree of burden that women currently face on their own or with limited support. It seems noteworthy that despite the statistics showing long diagnostic delays, there are no studies assessing the impact of this on health outcomes in endometriosis.
The review reflects how burdensome endometriosis is and is persuasive evidence that more needs to be done to support people with this condition. After all one in ten is a significant proportion of women.
If you’d like to read the review, you can do so here.
References
[1] Kalfas, M., Chisari, C., & Windgassen, S. (2022). Psychosocial factors associated with pain and health‐related quality of life in Endometriosis: a systematic review. European Journal of Pain