The problem of delusional ugliness: is it really body dysmorphic disorder?

Currently, the DSM-IV allows individuals with dysmorphic delusions to be diagnosed with either delusional body dysmorphic disorder (BDD) and delusional disorder, somatic type (DDST). However, given the growing acceptance of a dimensional perspective in psychopathology, it is conceivable that future editions of the DSM may recommend the exclusion of the diagnosis of DDST whenever isolated dysmorphic delusions are present, arguing that the latter should be considered no more than a symptom of BDD. But is the concept of DDST condemned to extinction in favor of that of delusional BDD? While some studies suggest that non-delusional and delusional BDD/DDST may be indistinguishable from the clinical, neuroanatomical, and therapeutic perspectives, several facts support the utility of the DDST concept. Firstly, DDST is a wider construct than delusional BDD. Secondly, it is unclear whether DDST in general (as opposed to delusional BDD) belongs to the obsessive-compulsive spectrum. Thirdly, differential pharmacological response may not be an adequate criteria for blending non-delusional and delusional BDD/DDST. Fourthly, "delusional" BDD may not be delusional at all. Finally, there is more about delusion than just an "extreme" conviction. Future studies are urgently needed in order to substantiate our judgement regarding the existence of diagnostic limits between delusional BDD and DDST with dysmorphic delusions.