The partial serotonin agonist m-chlorophenyl-piperazine (m-CPP) has been
reported to increase obsessive-compulsive symptoms in some patients with
obsessive-compulsive disorder (OCD). The authors investigated the
underlying physiological mechanisms of this variable exacerbation by
imaging regional cerebral blood flow with the planar xenon-133 method after
administration of oral m-CPP (0.5 mg/kg). Seven patients who responded to
m-CPP with symptomatic exacerbation had a marked increase in global
cortical perfusion (18.1%), in contrast to the remaining 7 nonresponders to
m-CPP, who showed no change. These results suggest that m-CPP exacerbation
of OCD symptoms is associated with increased cortical blood flow.Abstract Teaser