“Lumping” and “splitting” medically unexplained symptoms: is there a role for a transdiagnostic approach?

Abstract

Medically unexplained syndromes (MUS) are defined as persistent bodily symptoms with functional disability but no explanatory pathology. They are highly prevalent in both primary and secondary care. In a meta-analysis of medically unexplained symptoms (not syndromes) in primary care, the percentage of patients complaining of at least one medically unexplained symptom ranged from 40.2 (95% CI 0.9-79.4%; I2 ¼ 98%) to 49% (95% CI 18-79.8%, I2 ¼ 98%) (Haller et al., 2015). MUS are associated with high levels of distress and do not respond easily to reassurance and simple explanation (Barsky & Borus, 1999). They are seen in all medical specialties. Fibromyalgia (FM) is frequently seen in rheumatology, irritable bowel syndrome (IBS) in gastroenterology, non-cardiac chest pain in cardiology, chronic fatigue syndrome (CFS) in infectious diseases, non-cardiac chest pain and functional palpitations in cardiology, hyperventilation syndrome in respiratory medicine, tension headache in neurology and multiple chemical sensitivity in allergy. These syndromes have mostly been studied in isolation. However, research has observed extensive symptom overlap with more than half of patients with one MUS condition fulfilling diagnostic criteria for at least one other MUS condition (Nimnuan et al., 2001). For this reason, Wessely et al. (1999) suggested advantages to redefining MUS as one syndrome. Fink & Schroder (2010) advocated a new overarching term, ''bodily distress syndrome'', to encompass all the different MUS. They submit that there is now substantial evidence that MUS conditions are not clearly distinct disease entities but rather a common phenomenon with different subtypes. They describe similarities in diagnostic criteria, aetiology, pathophysiological, neurobiology, psychological mechanisms, patient characteristics and treatment response. Some years earlier Yunus (2007) had suggested the generic term ''central sensitivity syndrome'' which suggests that the common mechanism underlying various MUS is central sensitisation which is the hyper-excitement of neurons in the central nervous system. However, this ''lumping'' hypothesis triggered much debate due to criticisms that overlap is not present between all the MUS. For instance, there is little symptomatic overlap between IBS and FM. Furthermore, the pathophysiology is not consistent across syndromes in that there is hyperactivity of corticotropin-releasing hormone neurons in FM but hypoactivity in CFS (Neeck & Crofford, 2000). From a cognitive behavioural perspective unhelpful beliefs and behaviours may differ markedly from one syndrome to another.The study of MUS often attracts debate and sometimes controversy. Even the label MUS comes under fire. Persistent physical symptoms (PPS) is a new patient-centred term that refers to MUS. For several reasons, we prefer to use the term PPS. Firstly, two surveys of different populations preferred the term. One group consisted of healthy subjects (Marks & Hunter, 2015) and the other group involved patients with CFS (Picariello et ...

Integrated GP care for patients with persistent physical symptoms: feasibility cluster randomised trial

“…Although PPS are many and varied, there are a range of common responses patients with PPS have to these symptoms, including avoidance of activity, poor sleep routines and catastrophising [21]. Transdiagnostic theory suggests that by targeting these common processes the same treatment can be used across different symptom clusters as long as flexibility is used with each individual patient [22].…”

“…Taking these previous findings into account, we developed an ‘integrated GP care’ approach. by providing self-help materials to patients and offering GP practices (clusters) training on how their GPs could utilise behavioural skills within short consultations [ 21 ].…”

Cognitive and Behavioral Differences Between Subtypes in Refractory Irritable Bowel Syndrome

“…PSYCHOLOGICAL ASSOCIATIONS WITH IBS SUBTYPES 20 need flexibility to accommodate specific responses within conditions (Chalder & Willis, 2017). The present findings demonstrate ways that this is important in CBT for IBS subtypes.…”

Fatigue interventions in long term, physical health conditions: A scoping review of systematic reviews

“…Interventions need to consider different possible underlying fatigue mechanisms across different LTCs (e.g. neurological versus inflammatory) so a flexible transdiagnostic approach may be needed, taking the pathology and characteristics of the patient populations into account [ 9 ]. Importantly, several reviews highlighted that interventions may need to focus specifically on fatigue in order to elicit the most benefit.…”

“…Recently there has been a move towards conceptualising fatigue as having commonalities across conditions and identifying person-specific (rather than solely illness-specific) factors across domains (i.e. behavioural, cognitive, physiological, social and emotional) [ 8 , 9 ] in a more transdiagnostic approach to management.…”