Joint hypermobility, anxiety and psychosomatics: two and a half decades of progress toward a new phenotype.

The strong association between a heritable collagen condition and anxiety was an unexpected finding that we first described in 1988 at the Hospital del Mar in Barcelona. Since then, several clinical and nonclinical studies have been carried out. In this paper, after summarizing the concept and diagnosis of joint hypermobility (hyperlaxity), we review case-control studies in both directions (anxiety in joint hypermobility and joint hypermobility in anxiety disorders) as well as studies on nonclinical samples, review papers and one incidence study. The collected evidence tends to confirm the strength of the association described two and a half decades ago. The common mechanisms that are involved in this association include genetics, autonomic nervous system dysfunctions and interoceptive and exteroceptive processes. Considering clinical and nonclinical data, pathophysiological mechanisms and the presented nosological status, we suggest a new Neuroconnective phenotype, which around a common core Anxiety-Collagen hyperlaxity, includes five dimensions: behavioral, psychopathology, somatic symptoms, somatosensory symptoms, and somatic illnesses. It is envisaged that new descriptions of anxiety disorders and of some psychosomatic conditions will emerge and that different nosological approaches will be required. The Neuroconnective model is a proposal that is under study and may be useful for clinical practice.