title: Examining DSM criteria for trichotillomania in a dimensional framework: implications for DSM-5 and diagnostic practice.
abstract: BACKGROUND
  Diagnosis of trichotillomania (TTM) requires meeting several criteria that aim to embody the core pathology of the disorder. These criteria are traditionally interpreted monothetically, in that they are all equally necessary for diagnosis. Alternatively, a dimensional conceptualization of psychopathology allows for examination of the relatedness of each criterion to the TTM latent continuum.
  
  
  OBJECTIVE
  First, to examine the ability of recently removed criteria (B and C) to identify the latent dimensions of TTM psychopathology, such that they discriminate between individuals with low and high degrees of hair pulling severity. Second, to determine the impact of removing criteria B and C on the information content of remaining diagnostic criteria. Third, to determine the psychometric properties of remaining TTM diagnostic criteria that remain largely unchanged in DSM-5; that is, whether they measure distinct or overlapping levels of TTM psychopathology. Fourth, to determine whether information content derived from diagnostic criteria aid in the prediction of disease trajectory (i.e., can relapse propensity be predicted from criteria endorsement patterns).
  
  
  METHODS
  Statistics derived from item response theory were used to examine diagnostic criteria endorsement in 91 adults with TTM who underwent psychotherapy.
  
  
  RESULTS
  The removal of two criteria in DSM-5 and psychometric validity of remaining criteria was supported. Additionally, individual trait parameters were used to predict treatment progress, uncovering predictive power where none previously existed.
  
  
  CONCLUSIONS
  Diagnostic criteria for TTM should be examined in dimensional models, which allow for nuanced and sensitive measurement of core symptomology in treatment contexts.
authors.affiliation: Department of Psychology, Texas A&M University, 4235 TAMU, College Station, TX, 77834, USA. Electronic address: davidhoughton@tamu.edu.
authors.forename: David C
authors.initials: DC
authors.lastname: Houghton
authors.affiliation: Department of Psychology, Texas A&M University, 4235 TAMU, College Station, TX, 77834, USA. Electronic address: balsis@tamu.edu.
authors.forename: Steve
authors.initials: S
authors.lastname: Balsis
authors.affiliation: MRC Unit on Anxiety & Stress Disorders, Department of Psychiatry and Mental Health, University of Cape Town, Rondebasch, Cape Town, 7700, South Africa. Electronic address: Dan.Stein@uct.ac.za.
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Stein
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, 2213 Elba St., Durham, NC, 27705, USA. Electronic address: scompton@duke.edu.
authors.forename: Scott N
authors.initials: SN
authors.lastname: Compton
authors.affiliation: Department of Psychology, Utah State University, 2810 Old Main Hill, Logan, UT, 84322, USA. Electronic address: michael.twohig@usu.edu.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Twohig
authors.affiliation: Department of Psychology, Marquette University, Cramer Hall, 317, Milwaukee, WI, 53233, USA. Electronic address: stephensaunders@marquette.edu.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Saunders
authors.affiliation: Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, 3535 Market St., Philadelphia, PA, 19104, USA. Electronic address: marty@mail.medd.upenn.edu.
authors.forename: Martin E
authors.initials: ME
authors.lastname: Franklin
authors.affiliation: Department of Psychology, Kent State University, 600 Hilltop Drive, Kent, OH, 44242, USA. Electronic address: aneal@kent.edu.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Neal-Barnett
authors.affiliation: Department of Psychology, Texas A&M University, 4235 TAMU, College Station, TX, 77834, USA. Electronic address: dowoods@tamu.edu.
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Woods
mesh_terms: D000328:Adult; D001526:Behavioral Symptoms / Q000175:diagnosis*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D011594:Psychometrics; D012008:Recurrence; D014256:Trichotillomania / Q000175:diagnosis*