Neurochemical correlates of behavioral treatment of pediatric trichotillomania

Tara S Peris; John Piacentini; Allison Vreeland; Giulia Salgari; Jennifer G Levitt; Jeffrey R Alger; Stefan Posse; James T McCracken; Joseph O'Neill

doi:10.1016/j.jad.2020.04.061

Neurochemical correlates of behavioral treatment of pediatric trichotillomania

J Affect Disord. 2020 Aug 1:273:552-561. doi: 10.1016/j.jad.2020.04.061. Epub 2020 May 3.

Authors

Tara S Peris¹, John Piacentini¹, Allison Vreeland¹, Giulia Salgari¹, Jennifer G Levitt¹, Jeffrey R Alger², Stefan Posse³, James T McCracken¹, Joseph O'Neill⁴

Affiliations

¹ Division of Child & Adolescent Psychiatry, Jane & Terry Semel Institute for Neuroscience at UCLA, Los Angeles, CA 90024, USA.
² UCLA Departments of Neurology and Radiological Sciences, Los Angeles, CA 90024, USA.
³ Departments of Electrical and Computer Engineering, Neurology, and Physics and Astronomy, University of New Mexico, Albuquerque, NM 87106, USA.
⁴ Division of Child & Adolescent Psychiatry, Jane & Terry Semel Institute for Neuroscience at UCLA, Los Angeles, CA 90024, USA. Electronic address: joneill@mednet.ucla.edu.

PMID: 32560953
DOI: 10.1016/j.jad.2020.04.061

Abstract

Background: Trichotillomania (TTM) is a chronic and impairing psychiatric disorder with suspected dysfunctional cortico-striato-thalamo-cortical (CSTC) circuit activity reflecting excitatory/inhibitory signaling imbalance. TTM neurochemistry is understudied, with no prior research using magnetic resonance spectroscopy (MRS). This pilot investigation examined associations between TTM diagnosis, symptom severity, and response to behavioral treatment with MRS neurometabolites glutamate (Glu) and γ-aminobutyric acid (GABA) in CSTC structures.

Methods: Proton echo-planar spectroscopic imaging (PEPSI) MRS was acquired from bilateral pregenual anterior cingulate cortex (pACC), caudate, putamen, globus pallidus, thalamus, and proximal white matter in 10 unmedicated girls with TTM, ages 9-17 years, before and after treatment, and from 13 age- and sex-matched healthy controls.

Results: Nine of 10 TTM patients were treatment responders. Pretreatment mean Glu and GABA did not differ significantly between participants and controls. Pretreatment TTM symptoms were correlated with Glu in (left + right) pACC (r = 0.88, p = 0.02) and thalamus (r = 0.82, p = 0.012), and were negatively correlated with pACC GABA (r = -0.84, p = 0.034). Mean GABA in putamen increased 69% (baseline to post-treatment) (p = 0.027). Higher pretreatment Glu in caudate, putamen, globus pallidus, and thalamus predicted greater symptom decreases with treatment (all r < -0.6, p < 0.05); higher caudate GABA predicted less treatment-related symptom decline (r = 0.86, p = 0.014).

Limitations: Small sample, GABA quantified with spectral fitting rather than editing.

Conclusion: Consistent with other neuroimaging, MRS reveals discrete CSTC chemical changes with effective behavior therapy, and possibly with TTM etiology. TTM symptoms relate to excess excitatory versus inhibitory signaling in pACC and thalamus; symptom improvement may reflect reduced excitatory drive of the CSTC direct-pathway activity.

Keywords: Behavioral treatment; Children; GABA; Glutamate; MRS; Trichotillomania (hair-pulling disorder).

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Review

MeSH terms

Adolescent
Behavior Therapy
Child
Female
Glutamic Acid
Gyrus Cinguli / diagnostic imaging
Humans
Obsessive-Compulsive Disorder*
Trichotillomania* / diagnostic imaging
Trichotillomania* / therapy

Substances

Glutamic Acid

Grants and funding

R01 MH081864/MH/NIMH NIH HHS/United States