“…A total of eight different factor structures have been suggested in the literature as providing the 'best fit' to the HADS item structure (1 unidimensional distress, 2 bidimensional consisting anxiety and depression, and 5 tridimensional consisting of anxiety depression and restlessness/agitation/negative-affectivity) [1,8,[28][29][30][31][32]. Furthermore, two bifactor structures were considered since this model has been shown to provide the best fit in other studies jointly assessing symptoms of anxiety and depression [17,18].…”