“…A second gap in the research concerns the paucity of cognitive-behavioral anger management programmes which include a follow-up assessment, as a means of examining whether the effects of the intervention are temporary or sustained (van de Wiel, Matthys, Cohen-Kettenis, & van Engeland, 2002). While some researchers question the maintenance effects of cognitive-behavioral group interventions (Humphrey & Brooks, 2006), others report that effects are sustained (Broota & Sehgal, 2004; Muris, Meesters, Vincken, & Eijkelenboom, 2005; Whitfield, 1999) or, indeed, enhanced (Hemphill & Littlefield, 2001; Martsch, 2005) when follow-up assessments are conducted.…”