TABLE 4.

Summary of works about brain connectivity related to SAD.

Connectivity	Study	Participants	Main findings
Functional connectivity	Xing et al., 2017 Yuan et al., 2016 Bhaumik et al., 2017 Imperatori et al., 2019 Prater et al., 2013 Qiu et al., 2011 Hahn et al., 2011 Etkin and Wager, 2007 Phan et al., 2006 Kawaguchi et al., 2016 Klumpp et al., 2012	gSAD and HC gSAD and HC HAS vs. HC HAS vs. HC HAS vs. HC HAS vs. HC HAS vs. HC HAS vs. HC HAS vs. HC HAS vs. HC HAS vs. HC	The WPLI findings show an increase in the mid-frontal coherence in the theta rhythm, showing that the gSAD has higher connectivity at resting compared to the HC group. GSAD patients display high decreased connection in the amygdala compared with baseline after application of CBT. Unanimity links used to differentiate SAD subjects are broadly located within or through the DMN Lower beta FC is shown in the right and the right amygdala and anterior cortex HSA displayed decreased FC between the amygdala and cortex compared to HC while watching fearful faces. Relative to HC, SAD individuals show less connection in gyrus and the left cortical sites within the DMN Greater functional amygdala activation Greater functional amygdala activation in response to social stimuli Greater functional amygdala activation response to harsh faces Bilateral insular volume was reduced in patients with SAD Insula-prefrontal connectivity has shown a higher hyperactivity to threat stimulus in SAD individuals compared to HC
Effective connectivity	Liao et al., 2010 Sladky et al., 2013 Freitas-Ferrari et al., 2010 Engel et al., 2009 Shahabi and Moghimi, 2016 Bae et al., 2017	HAS vs. HC HAS vs. HC HAS vs. HC HAS vs. HC HAS vs. HC Alcoholics vs. normal subjects	In SAD, it was found that the effect of gyrus to amygdala is decreased, while the causal effect in the amygdala and the occipital cortex was greater than HC. SAD people, obvious correlate from the frontal cortex to the amygdala was observed, suggesting the presence of excitatory connectivity. An abnormal amygdala in SAD patients. Also an abnormal amygdala in SAD patients The perceived valence was positively correlated with the frontal inter-hemispheric flow but negatively correlated with the parietal bilateral connectivity Findings reveal a distinguished impacts in addictive alcohol compared to HC