Persistent postural-perceptual dizziness (PPPD), psychosomatic or not? The debate continues
Reviewed by Victor Osei-Lah

PPPD continues to provoke debate since the diagnostic criteria emerged in 2017. This review covers two commentaries because they are best considered together: the first one, by HK and BS-U, concluded that PPPD is a psychosomatic disorder (in fact, ‘a prototypical one’) and the second by JPS, the lead author of the diagnostic criteria, countered the points raised in the first. In arriving at their unequivocal conclusion, HK/BS-U compared the key diagnostic criteria of PPPD with somatic symptom disorder (SSD – DSM V) or bodily distress disorder (BDD – ICD 11). Their broad point was against PPPD being a distinct entity separate from SSD and BDD. They emphasised that only a single somatic symptom is sufficient to diagnose SSD, hence “a high number of patients with PPPD will therefore fulfil the SSD or BDD’’. Several criticisms were made, in particular the removal of anxiety in the concept of PPPD; that functional or psychosomatic disorders are “unrelated to structural or cellular deficits”, and the inclusion of criterion E of PPPD – “Symptoms are not better accounted for by another disease or disorder” – to imply a diagnosis of exclusion. To support their point that structural/cellular deficits exist in so-called ‘functional disorders’, they argued that chronic stress, a major factor in psychosomatic disorders and PPPD, cause “hormonal, neurobiological and immune alterations, changes in muscle tone, heart rate variability or breathing pattern”. In response, JPS welcomed the important critique as an opportunity for clarification, which will no doubt inform future revisions of PPPD based on evidence, including those from the field of psychosomatic medicine. The East-West divide means practitioners across the world view psychosomatic, psychological and psychiatric disorders differently. Hence, one primary goal was to formulate a set of criteria that would be understood by all. A selection of several points of clarification made by JP are as follows: that the concept of chronic stress “provides neither an explanation for the specific clinical symptoms of PPPD nor inspiration for detailed investigations of its pathophysiological processes” because it is “generically applicable to other medical conditions”; that the statement, “symptoms are not better accounted for by another disease or disorder” does not mean a diagnosis of exclusion, but rather a prompt to practitioners to consider all symptoms, investigations and differential diagnoses before making a diagnosis of PPPD (as included in the footnotes of the guidelines); that emerging data on PPPD show that the rate of illness-anxiety beliefs in PPPD is similar in other medical conditions and does not differ from patients with functional versus structural vestibular disorders, justifying the exclusion of anxiety in the PPPD guidelines. Furthermore, the PPPD guidelines made provisions for diagnosing somatic symptom disorder in addition to, or instead of, PPPD in the minority of patients who truly meet criteria for that psychiatric disorder. Worth a read.

Comment On: Persistent-postural perceptual dizziness (PPPD): Yes, it is a psychosomatic condition!
Hufner K, Sperner-Unterweger B.
J VESTIB RES
2023;33(4):279-81.