Table 2. Imaging studies of striatal presynaptic DA parameters in drug naive and drug free patients with schizophrenia.

Parameter Study n Controls n Patients (DN/DF/T)a Radiotracer (/challenge) Method Outcome p Effect sizec
DOPA accumulation (Reith et al., 1994b) 13 5 (4/0/1) [18F]DOPA Kinetic k3 <0.05 0.91
(Hietala et al., 1995) 7 7 (7/0/0) [18F]DOPA Graphical Ki <0.05 1.54
(Dao-Castellana et al., 1997) 7 6 (2/4/0) [18F]DOPA Graphical Ki ns 0.30
(Lindstrom et al., 1999) 10 12 (10/2) [11C]DOPA Graphical Ki <0.05 0.77
(Hietala et al., 1999) 13 10 (10/0) [18F]DOPA Graphical Ki <0.05 1.09
(Elkashef et al., 2000) 13 19 (0/9/10) [18F]DOPA Ratio Ki <0.05 -0.65
(Meyer-Lindenberg et al., 2002) 6 6 (0/6/0) [18F]DOPA Graphical Ki <0.02 1.96
(McGowan et al., 2004) 12 16 (0/0/16) [18F]DOPA Graphical Ki 0.001 1.6
Amphetamine-induced DA release (Laruelle et al., 1996) 15 15 (2/13/0) [123I]IBZM/ amphetamine Equilibrium Delta BP <0.05 1.51
(Breier et al., 1997) 18 18 (8/10/0) [11C]raclopride/ amphetamine Equilibrium Delta BP <0.05 1.73
(Abi-Dargham et al., 1998) 16 21 (1/20/0) [123I]IBZM/ amphetamine Equilibrium Delta BP <0.05 1.07
Baseline DA concentration (Abi-Dargham et al., 2000) 18 18 (8/10/0) [123I]IBZM/AMPT Equilibrium Delta BP <0.05 1.43
(Kegeles et al., 2006) 18   [11C]raclopride/ AMPT Equilibrium Delta BP <0.05 in preDCAb  
DAT density (Laakso et al., 2000) 9 9 (9/0/0) [18F]CFT Ratio S/C <0.05 0.11
(Laruelle et al., 2000) 22 22 (2/20/0) [123I]CIT Equilibrium BP <0.05 -0.43
(Hsiao et al., 2003) 12 12 (12/0/0) [99mTc]TRODAT Ratio S/Occ ns 0.22

a DN = drug naive; DF = drug free; T =treated with antipsychotics b precommissural caudate, c Effect size calculated as (Mean patients -mean controls) / SD controls.