Moreover, a recent meta-analysis by Ma (2014) studied the effects of antidepressants on brain activity underlying emotional processing. Their results showed that antidepressant treatments had effects on the activation of limbic core structures such as the amygdala, the thalamus, and ACC, and in other emotional processing structures like MPFC, the insula, and the putamen. Antidepressant medication increased the activity of these structures when the subjects processed positive emotions, whereas the same medication decreased the activity of the same structures while processing negative emotions. For these reasons, it is perfectly plausible to expect that, after the same treatments, the depressed patients will present changes in connectivity related to illness improvement.

most of the evidence in the literature suggests that, in MDD, connectivity networks at rest and the connectivity networks activated during specific tasks are all altered (Wang et al., 2012). Accordingly, affective disorders have been linked to alterations of the Default Mode Network (DMN), the Affective Network (AN), the Salience Network (SN), and the Cognitive Control Network (CCN), among others (Dutta et al., 2014).

an increase in the activation of the mPFC, the amygdala, and the hippocampus in depressed subjects with respect to the control subjects (Rose et al., 2006; Siegle et al., 2007; Wise et al., 2014)