Reduced Basal Ganglia Volumes in Trichotillomania Measured via Morphometric Magnetic Resonance Imaging Richard L. O'Sullivan, Scott L. Rauch, Hans C. Breiter, Igor D. Grachev, Lee Baer, David N. Kennedy, Nancy J. Keuthen, Cary R. Savage, Peter A. Manzo, Verne S. Caviness, and Michael A. Jenike A morphometric magnetic resonance imaging (MRI) study compared volumes of brain structures in 10 female subjects with trichotillomania (repetitive hair-pulling) versus 10 normal controls matched for sex, age, handedness, and education. Three-dimensional MRI scans were blindly normalized and segmented using well-characterized semiautomated intensity and differential contour algorithms by signal intensity-frequency histograms. Consistent with one a priori hypothesis, left putamen volume was found to be significantly smaller in trichotillomania subjects as compared with normal matched controls. This is the first report of a structural brain abnormality in trichotillomania. Results are discussed in terms of putative relationships between trichotillomania, Tourette's syndrome, and obsessive- compulsive disorder. © 1997 Society of Biological Psychiatry Key Words: Morphometric magnetic resonance imaging, trichotillomania, basal ganglia, putamen BIOL PSYCHIATRY 1997;42:39-45 Introduction Trichotillomania (TTM) is an underrecognized disorder affecting up to 3.4% of the population (Christenson et al 1992). Characterized by repetitive urges to pull hair and frequently associated with focal paresthesias, the act of From the Department of Psychiatry (RLO, SLR, HCB, IDG, LB, NJK, CRS, PAM, MAJ); Department of Radiology (SLR, HCB, DNK); and Department of Neurology, (DNK, VSC), Massachusetts General Hospital and Harvard Med- ical School, Charlestown, Massachusetts. Address reprint requests to Richard L. O'Sullivan, MD, Psychiatric Neuroscience Program, Obsessive Compulsive Disorders Clinic and Research Unit, Depart- ment of Psychiatry, Massachusetts General Hospital-East, 9th Floor, 149 Thirteenth Street, Charlestown, MA 02129. Received September 6, 1995; revised April 11, 1996. pulling is often pleasurable and associated with temporary relief of these urges (Minicbiello et al 1994). Typically emerging in early adolescence, hair-pulling may result in a range of consequences, from mild hair loss to irrevers- ible baldness with a potentially severe impact on self- image and social as well as occupational functioning (Sofiano et al 1996). Although classified as an impulse control disorder (American Psychiatric Association 1994), TTM is com- monly referred to as "compulsive" hair-pulling and em- bodies phenomenological elements similar to compulsions in obsessive-compulsive disorder (OCD) (Swedo and Leonard 1992). For example, hair-pullers often describe a © 1997 Society of Biological Psychiatry 0006-3223/97/$17.00 PII S0006-3223(96)00297-1