ABSTRACT
BACKGROUND: Previous imaging studies demonstrated that schizophrenia is associated with increased amphetamine-induced dopamine (DA) release in the striatum, most pronounced during episodes of illness exacerbation. Schizotypal personality disorder (SPD) is a schizophrenia spectrum disorder, genetically related to schizophrenia. The goal of this study was to investigate striatal DA function in patients with SPD. METHODS: In our study, 13 SPD patients and 13 matched healthy control subjects underwent single photon emission computed tomography (SPECT) scan during bolus plus constant infusion of the D2/3 radiotracer [123I]iodobenzamide (IBZM). Striatal specific to nonspecific equilibrium partition coefficient (V(3)") was measured at baseline and following amphetamine administration (.3 mg/kg). RESULTS: No significant differences were observed in baseline V(3)" between groups. Amphetamine induced a larger decrease in [123I]IBZM V(3)" in SPD patients (-12 +/- 5%) compared with control subjects (-7 +/- 5%, p =.03). CONCLUSIONS: The reduction in [123I]IBZM V(3)" induced by amphetamine in SPD was similar to that observed in remitted schizophrenia patients (-10 +/- 9%, n = 17), but significantly lower than that observed during illness exacerbation (-24 +/- 13%, n = 17). This suggests that DA dysregulation in schizophrenia spectrum disorders might have a trait component, present in remitted patients with schizophrenia and in SPD, and a state component, associated with psychotic exacerbations but not SPD.
Subject(s)
Amphetamine/pharmacology , Benzamides , Corpus Striatum/metabolism , Dopamine/metabolism , Pyrrolidines , Schizoid Personality Disorder/metabolism , Adult , Amphetamine/blood , Analysis of Variance , Case-Control Studies , Central Nervous System Stimulants/pharmacology , Dopamine Antagonists , Female , Humans , Iodine Radioisotopes , Male , Middle Aged , Psychiatric Status Rating Scales , Receptors, Dopamine D2/metabolism , Schizoid Personality Disorder/diagnostic imaging , Tomography, Emission-Computed, Single-PhotonSubject(s)
DNA/metabolism , Leukocytes/metabolism , Mental Disorders/blood , Adolescent , Adult , Depressive Disorder/metabolism , Female , Histocytochemistry , Humans , Male , Mental Disorders/metabolism , Middle Aged , Psychotic Disorders/metabolism , Schizoid Personality Disorder/metabolism , Schizophrenia, Paranoid/metabolismABSTRACT
Developments in the analysis and pharmacokinetics of lithium, and the role of the pharmacist in the management of lithium therapy in affective disorders, are described. Research showing that lithium levels in the brain may be better predicted from erythrocyte lithium levels than plasma levels is reviewed. Also reviewed is lithium kinetics in affective disorders. The pharmacist (1) determines relevant aspects of the patient's condition, (2) develops an appropriate blood sampling schedule, (3) initiates and maintains a serial lithium erythrocyte and plasma patient profile, (4) evaluates erythrocyte and serum levels in relation to established criteria to provide a basis for differential diagnosis of the patient, and (5) individualizes lithium dosage and schedules. Four cases are used to illustrate this approach. It is suggested that outpatient mental health clinics would be likely settings for the further development of this clinical role.
