The scatter plots relating the 1 month postpartum (T1) to 4 months postpartum (T2) changes in the periaqueductal gray (PAG)-hypothalamus resting-state functional connectivity (rs-FC) to T1/T2 Postpartum Bonding Questionnaire (PBQ) subscales of impaired bonding (IB) (A, B), rejection and pathological anger (RPA) (C, D) and infant-focused anxiety (IFA) (E, F). Abbreviations: BT, buprenorphine treatment for opioid use disorder; CG, comparison group