Figure 2
Correlations between the left basal ganglia glutamate and anhedonia and psychomotor speed in depressed patients. (a) Logged values of absolute glutamate concentrations in the left basal ganglia were correlated with the IDS-SR–Anhedonia subscale (β=0.42, t=3.03, P=0.004). (b) Log absolute basal ganglia glutamate concentrations were correlated with finger-tapping frequency on the FTT (β=−0.40, t=−2.96, P=0.005). (c) Log absolute basal ganglia glutamate concentrations were correlated with log simple reaction time assessed using the CANTAB (β=0.35, t=2.44, P=0.019). (d) Log absolute basal ganglia glutamate concentrations were correlated with performance on the DSST (β=−0.36, t=−2.57, P=0.01). Statistical values controlling for covariates including age, sex, race, body mass index, smoking status, Hamilton Scale of Depression scores and plasma CRP are indicated in parentheses. CANTAB, Cambridge automated neuropsychological test battery; DSST, digit symbol substitution test; FTT, finger-tapping test; IDS-SR, inventory for depressive symptoms-self rated.
