Concern regarding physical appearance is normal, but can sometimes reach an intensity which renders it a "disorder" (body dysmorphic disorder, or BDD). The rate of BDD in the general population is not clear, but sufferers are over-represented in psychiatric populations and in those seeking cosmetic surgery. BDD shows extensive psychiatric comorbidity, including depression, social phobia, and obsessive-compulsive disorder. BDD is treatable, with serotonergic antidepressants (e.g., selective serotonin reuptake inhibitors) and cognitive-behavioural treatments being the most effective.