“…In addition, there is also a range of methodological issues that arise when considering therapist effects. In terms of substantive findings, differences in effectiveness between therapists have been reported in some RCTs (e.g., Huppert, Bufka, Barlow, Gorman, & Shear, 2001), while others have reported small or non-significant effects (e.g., Clark et al, 2006;Wilson, Wilfley, Agras, & Bryson, 2011). These conflicting results are exemplified in two independent analyses of the same data, drawn from the National Institute for Mental Health's Treatment of Depression Collaborative Research Project (NIMH TDCRP; Elkin et al, 1989).…”