Psychological and Psychophysical Predictors and Inhibitory Control of Chronic Pain

Introduction: Back pain, the leading cause of disability worldwide, often progresses from acute to chronic stages. The subacute phase, characterized by distinct pain features, presents a critical opportunity to identify predictive factors and implement early interventions to prevent chronicity. Objective: The studies aimed to identify predictors of chronic back pain (CBP) by examining psychological factors and psychophysical markers in individuals with subacute back pain (SABP), assessing their influence on long-term pain outcomes and their role in the transition from subacute to chronic pain. Method: Study One analyzed 75 SABP participants, assessing psychological factors via the Örebro Musculoskeletal Pain Questionnaire (ÖMPQ) and additional emotional, cognitive, behavioural, and social measures at baseline. Factors from dimensionality reduction were us ed to predict pain severity and interference at 6-month follow-up. Study Two included 88 SABP, 35 CBP, and 40 HC (Healthy Control), assessing central sensitization (via Quantitative sensory tests) and descending pain inhibition (via stress-induced pain modulation tests). Psychophysical parameters differentiating groups were used to predict 6-month pain outcomes in SABP. Results: In Study One, the ÖMPQ and the Pain Vigilance and Awareness Questionnaire (PVAQ) scores significantly predicted pain severity, while the ÖMPQ, the Pain Behaviour Checklist, and PVAQ scores significantly predicted pain-related interference after six months, with PVAQ (pain hypervigilance) emerging as the strongest predictor of both outcomes, independent of baseline pain. Study Two showed that the central sensitization index—Wind-up Ratio—was present only in CBP. SABP individuals exhibited impaired pain inhibition in stress-induced pain modulation tests, whereas CBP participants showed responses similar to HC, potentially moderated by long-term stress and related anxiety and depression. Psychophysical measures did not predict SABP chronicity after six months. Discussion: Both studies highlight the multidimensional nature of pain and the interplays between psychological and psychophysical factors in the development of CBP. Psychological factors, especially pain hypervigilance, are stronger predictors of back pain chronicity in the subacute stage than psychophysical markers, which may appear more relevant in established chronic pain.