Purpose – The purpose of this paper is to explore the ways in which trauma may manifest both in terms of internalising and externalising symptoms. Design/methodology/approach – The paper will argue that the effects of trauma can contribute to victims engaging in problematic behaviours (such as aggression) both towards themselves and others which may require them to attend treatment programmes to target these problem behaviours. However, standard interventions designed to target these problem behaviours do not sufficiently take into account the effects of trauma in terms of attending to the therapy interfering behaviours which are brought to treatment. The paper will argue that these trauma related therapy interfering behaviours should be attended to prior to the client engaging in specific groups to target other problem behaviours (e.g. aggression). Findings – Clients who are referred for standard group based interventions to target problem behaviours such as aggression towards themselves or others should be offered a trauma intervention first in order to improve concentration, reduce drop-out rates and enhance feelings of safety to engage effectively in the group. Group based Eye Movement Desensitisation and Reprocessing (EMDR) should be used as a method of targeting therapy interfering behaviours associated with the effects of trauma and this should also incorporate meditation and neurobiologically informed approaches. Standard target problem behaviour groups should be adapted and modified to account for the role of trauma in information processing. Originality/value – The paper will introduce Trauma Informed Additional – Programme (TIA-P) which is a newly designed group designed to assist clients to tolerate and modify therapy interfering behaviours which are present as a result of trauma in order that they can then go on to attend standardised interventions. The TIA-P attends to the latest research in relation to the treatment of trauma utilising EMDR within the group to enhance safety and reduce therapy interfering behaviours.