236 Obsessive-Compulsive and Related Disorders
ing, ordering, and counting compulsions); fo rbidden or taboo thoug hts (e.g., aggressive,
sexual, and religious obsessions and related co mpulsions); and harm (e .g., fears of harm to
oneself or others and related checking comp ulsions). The tic-related specifier of OCD is
used when an individual has a curren t or past history of a tic disorder.
Body dysmorphic disorder is characterize d by preoccupation with one or more per-
ceived defects or flaws in physical appearance that are not observable or appear only slight
to others, and by repetitive  behaviors (e.g., mirror checking, excessive grooming, skin
picking, or reassurance seeking) or mental acts (e.g., comparing one’s appearance with that
of other people) in response to the appear ance concerns. The appearance preoccupations
are not better explained by concerns with body fat or weight in an individual with an eat-
ing disorder. Muscle dysmorphia is a form of body dysmorphic disord er that is character-
ized by the belief that one’s body build is too small or is insu fficiently muscular.
Hoarding disorder is characterized by persis tent difficulty discarding or parting with
possessions, regardless of their actual value, as a result of a strong perceived need to save
the items and to distress associated with disc arding them. Hoarding disorder differs from
normal collecting. For example, symptoms of hoarding disorder result in the accumula-
tion of a large number of possessions that co ngest and clutter active living areas to the ex-
tent that their intended use is substantially  compromised. The excessive acquisition form
of hoarding disorder, which characterizes most  but not all individuals with hoarding dis-