Study	Reason for exclusion
Amerikaner 1982	Participants did not specifically have intellectual disabilities
Bagner 2007	Intervention was based on parent‐child interactions (parent training)
Baker 1971	Non‐randomised study
Bearss 2013	Not randomised. No control group
Benson 1986	Non‐randomised 4‐armed study. No 'no‐treatment' control group
Bird 2000	Descriptive study. No randomisation or concealment of allocation. Poor design
Bornstein 1980	Non‐randomised study. Participants did not specifically have aggressive behaviour
Brightman 1982	Study about parent training
Brookman‐Frazee 2012	No control group. It is not clear whether participants had intellectual disabilities
Carr 2006	Participants did not specifically have aggressive behaviour
Clement 1967	Participants did not specifically have intellectual disabilities or aggressive behaviour
Durand 2013	Participants did not specifically have intellectual disabilities. Intervention based on parent training
Edmonson 1983	Aimed at improving prosocial behaviour, rather than aggressive behaviour
Eikeseth 2007	Non‐randomised study. Participants did not appear to have intellectual disabilities
Eikeseth 2012	Non‐randomised study. Not clear what proportion of participants had intellectual disabilities. Study not specifically about aggressive behaviour
Eldevik 2006	Non‐randomised study. Not specifically about aggressive behaviour
Fava 2011	Non‐randomised study. Not specifically about aggressive behaviour
Feldman 2002	No control group
Gates 2001	Study about parent training
Gresham 1982	Non‐randomised study. No concealment of allocation. No instrument for recording aggressive behaviour
Grey 2007	Non‐randomised study
Hagiliassis 2005	Participants were not clearly aggressive although they all had difficulties with anger control and expression of anger. Not all participants had intellectual disabilities
Hall 1973	Descriptive study, not a clinical trial
Hassiotis 2009	Not specifically about aggressive behaviour
Koenig 2010	Participants did not have intellectual disabilities. Study not specifically about aggressive behaviour
Leblanc 1995	Investigates the impact of social skills training on pro‐social behaviours in preschoolers with developmental delays. No data available on outward‐directed aggression
Lindsay 2004	Non‐randomised study
Lovaas 1987	Non‐randomised study. No “no treatment control group”. Participants did not specifically have intellectual disabilities or aggressive behaviour
Lowe 1996	Non‐randomised study. Not specifically about aggressive behaviour
Mate‐Kole 1999	Not all participants had intellectual disabilities. Study not specifically about aggressive behaviour
Murphy 1978	No “no treatment control group”. Study not specifically about aggressive behaviour
Reitzel 2013	Not specifically about aggressive behaviour
Rickards 2009	No "no treatment" control group. Parent‐ or family‐based intervention
Roberts 2006	Study about parent training. Participants were not aggressive
Roeden 2014	Non‐randomised study
Rose 2000	Study appears to describe some of the data included in Rose 2005 group treatment for aggressive behaviour. No randomisation. No proper wait‐list control
Rose 2005	Study describes 10 groups for aggressive behaviour held over 5 years. Some people on the waiting list were assessed but there was no random allocation and therefore no proper wait‐list control
Rose 2009	Non‐randomised study
Schnitzer 2007	Non‐randomised study. Not specifically about aggressive behaviour
Shechtman 2005	Not specifically about aggressive behaviour
Smith 1997	Study about development of pro‐social behaviours rather than ameliorating aggressive behaviour
Strauss 2012	Non‐randomised study of parent training
Tavormina 1975	Study about parent training
Taylor 2002	Wait‐list controlled study of individual cognitive behavioural therapy for anger. Pilot study, and the data have been included in Taylor 2005
To 2000	Small scale non‐randomised trial of efficacy of progressive relaxation in reducing aggressive behaviours, which included self injury and forensic behaviours and as such was not part of this review
Wacker 1998	Study about parent training
Wiggs 1999	Not specifically about aggressive behaviour
Willner 2007	Non‐randomised study