Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:The current results in healthy participants also align well with studies showing impaired value-based decision-making across substance-use disorders (Lubman et al, 2009; Paulus, 2007) and with the growing evidence for dysregulation of MOR function across addictions (Ghitza et al, 2010; Mick et al, 2015).
Category: