Editing Trichotillomania (section)

=== Classification ===
Trichotillomania is defined as a self-induced and recurrent loss of hair.<ref name="Sah"/> It includes the criterion of an increasing sense of tension before pulling the hair and gratification or relief when pulling the hair.<ref name="Chamberlain"/> However, some people with trichotillomania do not endorse the inclusion of "rising tension and subsequent pleasure, gratification, or relief" as part of the criteria<ref name="Chamberlain">{{cite journal | vauthors = Chamberlain SR, Menzies L, Sahakian BJ, Fineberg NA | title = Lifting the veil on trichotillomania | journal = The American Journal of Psychiatry | volume = 164 | issue = 4 | pages = 568–574 | date = April 2007 | pmid = 17403968 | doi = 10.1176/appi.ajp.164.4.568 }}</ref> because many individuals with trichotillomania may not realize they are pulling their hair, and patients presenting for diagnosis may deny the criteria for tension prior to hair pulling or a sense of gratification after hair is pulled.<ref name="Sah"/>

Trichotillomania may lie on the [[obsessive-compulsive spectrum]],<ref name="Huynh2013"/> also encompassing [[obsessive-compulsive disorder]] (OCD), [[body dysmorphic disorder]] (BDD), nail biting ([[onychophagia]]) and skin picking ([[dermatillomania]]), [[tic disorder]]s and [[eating disorder]]s. These conditions may share clinical features, genetic contributions, and possibly treatment response; however, differences between trichotillomania and OCD are present in symptoms, neural function and cognitive profile.<ref name="Chamberlain"/> In the sense that it is associated with irresistible urges to perform unwanted repetitive behavior, trichotillomania is akin to some of these conditions, and rates of trichotillomania among relatives of OCD patients is higher than expected by chance.<ref name="Chamberlain"/> However, differences between the disorder and OCD have been noted, including: differing peak ages at onset, rates of [[comorbid]]ity, gender differences, and neural dysfunction and cognitive profile.<ref name="Chamberlain"/> When it occurs in early childhood, it can be regarded as a distinct clinical entity.<ref name="Chamberlain"/>

Because trichotillomania can be present in multiple age groups, it is helpful in terms of prognosis and treatment to approach three distinct subgroups by age: preschool age children, preadolescents to young adults, and adults.<ref name="Sah"/>

In preschool age children, trichotillomania is considered benign. For these children, hair-pulling is considered either a means of exploration or something done subconsciously, similar to nail-biting and thumb-sucking, and almost never continues into further ages.<ref name=":0">{{Cite book |doi=10.1007/978-3-319-72134-7_10 |chapter=Trichotillomania (Hair Pulling Disorder) |title=Alopecia Areata |pages=63–66 |year=2018 |last1=Khan Mohammad Beigi P |isbn=978-3-319-72133-0 }}</ref>

The most common age of onset of trichotillomania is between ages 9 and 13. In this age range, trichotillomania is usually chronic, and continues into adulthood. Trichotillomania that begins in adulthood most commonly arises from underlying psychiatric causes.<ref name=":0" />

Trichotillomania is often not a focused act, but rather hair pulling occurs in a "trance-like" state;<ref name="Tay">{{cite journal | vauthors = Tay YK, Levy ML, Metry DW | title = Trichotillomania in childhood: case series and review | journal = Pediatrics | volume = 113 | issue = 5 | pages = e494–e498 | date = May 2004 | pmid = 15121993 | doi = 10.1542/peds.113.5.e494 | doi-access =  }}</ref> hence, trichotillomania is subdivided into "automatic" versus "focused" hair pulling.<ref name="Sah"/> Children are more often in the automatic, or unconscious, subtype and may not consciously remember pulling their hair. Other individuals may have focused, or conscious, rituals associated with hair pulling, including seeking specific types of hairs to pull, pulling until the hair feels "just right", or pulling in response to a specific sensation.<ref name="Sah"/> Knowledge of the subtype is helpful in determining treatment strategies.<ref name="Sah"/>