BAX and Cognitive impairment: Mechanisms such as an altered blood–brain barrier integrity, facilitating the entry of pro‐inflammatory cytokines and toxins, as well as the apoptosis of human neurons and microglial cells, through the upregulation of Bax and downregulation of the anti‐apoptotic protein Bcl‐2 are considered to be responsible for the opioid‐associated cognitive impairment (Cunha‐Oliveira et al.