Assessing the efficacy and safety of STOP (successful treatment for paranoia)—an app-based cognitive bias modification therapy for paranoia: a randomised clinical trial protocol by Yiend, J, Taher, R, Fialho, C, Hampshire, C, Hsu, C, Kabir, T, Keppens, J, McGuire, P, Mouchlianitis, E, Peters, E, Ricci, T, Shergill, S, Stahl, D, Vamvakas, G, Jacobsen, P