Differences between women and men can be identified as sociocultural (gender) (Darnall & Suarez, 2009) and biological (sex) (Janine Austin Clayton, 2018; Cornelison & Clayton, 2017; National Institutes of Health, 2019). For the purpose of the present narrative review we will use sex/gender (SG) to acknowledge that findings may be driven by both sociocultural and biological factors (Pace et al., 2018; Streed & Makadon, 2017). It is known that SG differences exist on multiple levels, including neurobiology, neurochemistry and connectivity (Choleris, Galea, Sohrabji, & Frick, 2018; Cosgrove, Mazure, & Staley, 2007; Lind et al., 2017), with relevance for understanding SG differences in the neural mechanisms underlying addiction (Peltier et al., 2019; Sharrett-Field, Butler, Reynolds, Berry, & Prendergast, 2013); yet, even modern neuroimaging studies on addiction often do not account for SG in their analyses. To highlight this problem, a meta-analysis of structural imaging papers published through 2016 in the substance use field found that while female enrollment increased over time, enrollment was significant lower than males, particularly for the alcohol field (Lind et al., 2017). Further, while 79% of structural
