THBS1 and major depressive disorder: Since changes of synaptic plasticity are involved in the pathophysiology of stress responses, depression, and other psychiatric disorders (Duman and Aghajanian, 2012; Yuen et al., 2012; Treccani et al., 2014; Csabai et al., 2018), some researchers have targeted the putative involvement of astrocyte-expressed thrombospondins 1 (TSP1) and 2 in the consequences of stress, including the generation of depression-like behaviors, as well as in the synaptic effects of antidepressant treatments.