Table 2. Differences in amygdala reactivity between SLC6A3 dichotomized genotype subgroups in the affective face processing task.

Study population	Hemisphere	F (df)	P
Swedish sample (PET)
Reactivity (angry–neutral faces)
DAT	Left	5.07 (1,44)	0.029*
	Right	0.005 (1,44)	0.946
DAT × Diagnosis	Left	0.01 (1,44)	0.905
	Right	0.03 (1,44)	0.855
American sample (fMRI)
Reactivity (threatening faces–geometric shapes)
DAT	Left	5.13 (1,81)	0.026*
	Right	0.98 (1,81)	0.324

Abbreviations: DAT, dopamine transporter; fMRI, functional magnetic resonance imaging; PET, positron emission tomography; SAD, social anxiety disorder; SLC6A3, dopamine transporter gene.

For the analysis of variance of the Swedish sample, diagnostic subgroup (SAD and healthy volunteer, respectively) was included as a between group factor. For the analysis of both the Swedish and the US population, sex was included as a covariate. *P<0.05.