In order to begin identifying the important aspects of the HPA axis that are involved in the psychomotor, anxiety-like, and glucocorticoid response to oxycodone and Tat, mice were administered glucocorticoid receptor (GR) and/or corticotrophin-releasing factor-receptor (CRF-R) inhibitors concurrent with doxycycline administration (Figure 3A). Here, CRHR1 is linked to Anxiety.