These findings of compromised white matter microstructure in the inferior frontal regions using DTI are consistent with results reported previously in other impulsive behaviors (Hoptman et al., 2002
) and with the hypothesis that the inferior frontal brain region is involved in impulsive behaviors that involve poor decision-making, such as stealing unnecessary items (Bechara et al., 2000
). Kleptomania patients score high on tests of impulsivity (McElroy et al., 1991
; Grant and Kim, 2002
), and shoplifting may reflect an inability to balance the desire for immediate reward with punishment, an activity thought to involve prefrontal cortical function (Bechara et al., 2000
). These DTI findings in the inferior frontal regions may therefore reflect impaired connectivity in the tracts running from the limbic region to the thalamus and to the prefrontal region.
These findings may also have clinical and forensic implications. Clinically, psychotherapies that improve decision-making (for example, cognitive behavioral therapy) and pharmacotherapies that decrease impulsivity may be recommended in patients with kleptomania (Hollander, 1998
). Forensically, an understanding of whether shoplifting has a neurobiological basis may result in different recommendations to courts when repeat shoplifting is involved. For example, sentencing recommendations for individuals with kleptomania that include psychopharmacological and psychosocial treatments that possibly alter the underlying neurobiology may be more helpful in preventing recidivism than just incarceration.
This is a preliminary analysis, and the findings should be interpreted cautiously. First, although our acquisition protocols control for eddy current and susceptibility artifacts, such effects may have affected our measurements, particularly in anterior regions where such artifacts tend to be greater. However, it is unlikely that such effects would have interacted systematically with subject group to produce a bias favoring our hypothesis. Second, motion artifact, which could have affected the accuracy of our measurements, is unlikely to have produced a systematic bias between the groups. Third, although the groups did not differ significantly by age, the age range was broad, particularly in the kleptomania group. Accordingly, we controlled for age statistically in our main analysis; we recognize that this approach is not as powerful as tight matching of age during recruitment. Fourth, the sample size was small, and therefore replication in a larger sample with tight age matching is warranted. Finally, the sample was limited to kleptomania subjects who were female and without comorbidity. These findings, therefore, may not generalize to all female kleptomania subjects or to men with kleptomania.