Background: Scientific research has demonstrated impaired central pain modulation, cognitive and psychosocial deficits in patients with chronic whiplash associated disorders (CWAD). However, the underlying mechanisms remain unclear. To date, research regarding central pain modulation, cognitive performance and psychosocial characteristics in patients with chronic non-traumatic neck pain is lacking. Purpose: To examine central pain modulation (i.e. central sensitization), cognitive and psychosocial functioning in patients with CWAD and chronic idiopathic neck pain (CINP) compared to healthy individuals. Methods: Ninety-five women, 28 healthy pain-free controls, 35 CINP and 32 CWAD patients were enrolled. First, all participants filled out psychosocial questionnaires, namely the Short Form Health Survey (SF-36), the Neck Disability Index (NDI) and the Central Sensitization Inventory (CSI). Next, they were subjected to cognitive performance assessments and experimental pain measurements. Participants completed the modified Perceived Deficits Questionnaire (mPDQ) in order to evaluate self-perceived cognitive deficits. Subsequently, they performed the Trail Making Test (TMT), an objective cognitive test. Afterwards, pressure pain thresholds (PPTs), and conditioned pain modulation (CPM) were examined. The Kruskal-Wallis test was applied to explore differences between all study groups. Post-hoc comparisons with a significance threshold of p<0.017 were performed using the Mann-Whitney U test. Results: All study groups were comparable for age. Neck pain intensity and duration were comparable between both patient groups. Diminished health-related quality of life was observed in both neck pain groups compared to healthy individuals. Limitations on health-related quality of life as well as pain-related limitations on activities of daily living were higher in CWAD compared to CINP (SF-36, NDI). Furthermore, CWAD patients experienced more central sensitization symptoms compared to CINP, based on the CSI. CWAD patients displayed diminished psychomotor speed (TMT A) and decreased task-switching performance (TMT B) compared to CINP and controls. Further, both patient groups reported more self-perceived cognitive deficits (mPDQ) compared to healthy women. Noteworthy, within both patient groups, CWAD patients reported more severe cognitive deficits compared to CINP. Decreased PPTs were demonstrated at the m. Trapezius, m. Quadriceps, lumbar region and hand in CWAD and at the m. Trapezius in CINP, compared to healthy women. PPTs increased during the cold pressor test in the CINP and control group, indicating properly working CPM. However, in the CWAD group, PPTs at the m. Quadriceps remained the same during this CPM paradigm. Thereby, CPM efficacy was decreased in patients with CWAD compared to both other groups. Conclusion: Primary hyperalgesia was demonstrated in traumatic and non-traumatic neck pain patients. However, secondary hyperalgesia and decreased CPM efficacy was shown in CWAD but not in CINP, which is indicative for the presence of central sensitization in CWAD patients. Additionally, these results provide evidence for cognitive and psychosocial deficits in CWAD and to a lesser extent in CINP patients. Future research is warranted to unravel whether brain alterations are present in these patients and whether these alterations are related to clinical correlates of pain. Implications: These results provide preliminary evidence for the clinical importance to distinguish the rehabilitation approach between chronic traumatic and non-traumatic neck pain patients. It can be recommended that the evaluation of central sensitization, cognitive and psychosocial functioning should be taken into account. Accordingly, individually tailored therapy, which targets the observed disabilities, should be addressed. Funding Acknowledgements: Iris Coppieters, PhD student at University Ghent, is funded by the Special Research Fund of Ghent University (BOF-Ghent). Ethics Approval: This research was approved by the Ethics committee of the University Hospital Ghent, Belgium.