Correlation of the release of dopamine and psychiatric symptoms in Tourette's syndrome

Abstract

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Objectives: After receiving intravenous amphetamine, adults with Tourette's syndrome (TS) have (1) elevated dopamine release (DAR) in the putamen (Singer, et al., 2002; Wong, et al., 2007) and (2) worsened psychiatric (Brief Psychiatric Rating Scale (BPRS)) symptoms (Brasic, et al., 2007). This study further evaluates in adults with TS the correlation of striatal DAR and psychiatric symptom release={[(maximal BPRS score with amphetamine)-(maximal BPRS score with saline)]/[maximal BPRS score with saline]}.

Methods: Subjects included eighteen adults with TS (13 men and 5 women) aged 18 to 67 years (33.7+12.2) and ten healthy adults without TS aged 19 to 40 years (26.5+7.7). Psychiatric (BPRS) ratings were performed throughout two consecutive PET scans during which the subject received high-specific-activity [¹¹C]raclopride after saline and amphetamine challenges. DAR was determined separately for each side of the ventral striatum (VS) and the anterior (a) and posterior (p) dorsal striatum (caudate (C) and putamen (P)). The correlation of DAR and psychiatric symptom release was determined for each region.

Results:

Correlation coefficients between DAR and psychiatric symptom release in 18 adults with Tourette syndrome (TS)

Conclusions: In adults with TS, the release of dopamine in striatal regions strongly correlates with behavioral changes. Results confirm that abnormal phasic striatal dopaminergic activity contributes to psychiatric symptoms in TS.

Research Support: Essel Foundation, NARSAD, NIH(R01MH078175, K24DA00412, AA12839, NS38927, GCRC (NIH/NCRRM01RR00052), TSA