RELN and bipolar disorder: Furthermore, major depressive disorder and bipolar disorder, conditions linked to stress, have been associated with altered levels of diffuse ECM molecules, such as reelin, hyaluronan, and laminin (Fatemi et al., 2000; Guidotti et al., 2000; Laifenfeld et al., 2005b; Lubbers et al., 2014; Ventorp et al., 2016), and increased PNNs have been reported in the prefrontal cortex of suicide victims previously exposed to childhood maltreatment (Tanti et al., 2020).