“…hallucinations, delusions or negative symptoms. Early approaches were influenced more by the strictly behavioural psychology school, such as the use of contingency or reward approaches for reducing the occurrence of particular target behaviours (Nydegger, 1972;Haynes and Geddy, 1973), distraction procedures (Margo, Hemsley and Slade, 1981;James, 1983;Nelson et al, 1991), thought stopping (Samaan, 1975;Allen et al, 1983;) and the use of aversion therapy (Alford andTurner, 1976, Turner, Hersen andBellack, 1977). Whilst, successful reduction in the occurrence of target behaviours were frequently reported using these approaches, there was little evaluation of this type of approach in larger controlled trials and little evidence that the approaches generalised across situations or people (also see later section on contingency management).…”