Trichotillomania: Impulsive,compulsive or both?

Trichotillomania (hair-pulling disorder) is a relatively uncommon disorder that usually commences in early adolescence and appears to have a chronic course. The condition is seen more frequently in females and is often accompanied by other body-focused repetitive behaviours such as skin picking and nail biting. Recurrent hair pulling and hair loss usually involve the scalp, eyebrows or eyelids, but any area of the body where hair is present may be affected. Hair loss is variable and ranges from barely noticeable to massive.

Arunkumar et al. (2015) present acase of trichotillomania, which is interesting for several reasons. First, the onset of the condition was atypically late, at the age of 50 years. Second, this patient was suffering from a dermatological condition (contact dermatitis), which might exclude a diagnosis of trichotillomania. However, hair loss was not associated with contact dermatitis, as demonstrated by scalp biopsy. Third, this case was also unusual in that it occurred without any other psychiatric or neurological disorders. Finally, the patient responded very well to fluoxetine, although in controlled studies, this agent had failed to demonstrate efficacy for trichotillomania.

Trichotillomania has been a subject of debate in relation to the recent and ongoing changes in the diagnostic and classification systems. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and International Classification of Diseases and Related Health Problems–10th Revision (ICD-10) conceptualised trichotillomania as an impulse-control disorder, describing mounting tension that precedes hair pulling and a sense of relief or pleasure once the hair has been pulled. However, nearly a quarter of individuals (up to 23%) do not report tension prior to pulling hair nor the subsequent gratification. This has raised questions about trichotillomania as an impulse-control disorder and its links with other psychopathology.

A close relationship between trichotillomania and obsessive–compulsive disorder (OCD) was subsequently postulated, mainly on the basis of some similarities between the two conditions. For example, both hair pulling and compulsions are repetitive and often perceived as unreasonable, uncontrollable or irresistible, while the rituals surrounding hair pulling may resemble ritualistic compulsions. Also, OCD is found in individuals with trichotillomania with a frequency (13.4–16%) that is higher than the prevalence of OCD in the general population(0.3–3.2%). This ultimately led to a decision to classify trichotillomania among obsessive-compulsive and related disorders in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and to change its diagnostic criteria. Thus, both the tension and relief criteria before and after hair pulling were omitted and replaced by the requirement that the affected individual repeatedly attempts to decrease or stop hair pulling, which is analogous to the efforts to resist compulsions in OCD.

Does trichotillomania really resemble OCD? Both impulsive and compulsive features may be encountered in the same person with trichotillomania, for example, when they try to resist hair pulling, but ‘like’ the feeling afterwards. Some trichotillomania sufferers feel embarrassed about their hair pulling and try to hide it, yet they readily give in to urges to pull hair. It appears that both impulsivity and compulsivity are necessary for the conceptualisation of trichotillomania (Flessner et al., 2012) and that important differences between trichotillomania and OCD should not be overlooked. Thus, anxiety- or distress-inducing obsessions that occur prior to compulsions are different from the phenomena (urges, bodily sensations, various negative emotional states or specific cognitions about hair) that may precede hair pulling (Mansueto et al., 1997). Hair pulling often occurs automatically, out of one’s awareness, whereas only a small minority of compulsions is performed automatically. Unlike patients with OCD who are more likely to respond to serotonin reuptake inhibitors (SRIs) and exposure and response prevention, those with trichotillomania seem less likely to respond to SRIs and do better with habit reversal training.

A comprehensive review of the putative obsessive–compulsive spectrum disorders (Phillips et al., 2010) has concluded that the overlap between trichotillomania and OCD is ‘partial at best’ (p. 537). The same review also noted a lack of a close relationship between trichotillomania and other impulse-control disorders and suggested that due to a phenomenological and psychobiological relatedness to conditions like skin-picking disorder, trichotillomania might best be placed in a group of body-focused repetitive behaviour disorders. In the absence of such a group, trichotillomania was included in the obsessive–compulsive spectrum because there appeared to be no better solution, not because of its intrinsically close relationship with OCD (Starcevic and Janca, 2011).

In conclusion, the DSM-5 has overemphasised the link between trichotillomania and OCD. This has practical consequences in that some individuals may not meet the DSM-5 criteria for trichotillomania only because they do not seem to resist hair pulling. Indeed, this might have been the case with the patient described by Arunkumar et al. (2015) who had an ‘irresistible urge to pull her hair and a sense of intense, albeit short-lasting relief upon doing so’, which may imply that she made little or no effort to stop hair pulling.

See Letter by Arunkumar et al., 49(7): 665