Psychological and interactional characteristics of patients with somatoform disorders: Validation of the Somatic Symptoms Experiences Questionnaire (SSEQ) in a clinical psychosomatic population.

•The SSEQ assesses psychological characteristics relevant to somatoform disorders.•The SSEQ shows good internal consistency and construct validity.•The SSEQ predicts health-related quality of life and shows sensitivity to change.•The SSEQ can be used in research and clinical practice.