Martijn van Teffelen

Chapter 1 14 A promising target for improving the treatability of hostility is hostile interpretation bias (HIB). HIB is the tendency to interpret emotionally ambiguous stimuli in a hostile way. For example, consider a person waiting in line with his hands full of groceries. Suddenly, another person bumps into him, making him drop his groceries on the floor. The person who dropped his groceries might interpret the situation in a hostile (e.g., ‘the other person did it to provoke me’) or in a benign (e.g., ‘the other person didn’t see me’) way. A person with high levels of hostile interpretation bias is more likely to interpret the situation in a hostile way. Cognitive models of hostility state that HIB plays a central role in hostility (Allen et al., 2018; Crick & Dodge, 1994; Wilkowski & Robinson, 2008). Evidence shows that HIB increases the likelihood to experience anger and behave aggressively (Crick & Dodge, 1994; Epps & Kendall, 1995). Indeed, evidence reveals that interventions that target HIB, such as CR, show favorable outcomes in terms of hostility (DiGuiseppe & Tafrate, 2003). The current literature suggests that the effectiveness may be enhanced in two ways; first, by optimizing effects of therapist-provided CR, and second, by implementing computerized Cognitive Bias Modification for hostile interpretation. Optimization of Therapist-Provided CR One intervention targeting hostility that could potentially be enhanced is CR. Within CR patients are encouraged to identify and challenge hostile cognitions in past events that triggered anger and/or aggression, for example by gathering evidence for and against a hostile cognition. Findings suggest that enriching CR with mental imagery is a promising candidate for increasing its efficacy in reducing hostility. For example, two studies with social anxiety disorder patients show that incorporating mental imagery during CR led to greater symptom reduction compared to traditional CR (e.g., McEvoy et al., 2015; McEvoy & Saulsman, 2014). Additionally, integrating the use of mental imagery into existing treatment protocols for (childhood) trauma increased the effectiveness of several other interventions such as imaginary exposure and imagery rescripting (Arntz & Weertman, 1999; Ehlers et al., 2005; Smucker et al., 1995). Implementation of Computerized CBM-I Another potential way of reducing hostility is offered by cognitive bias modification for interpretation bias (CBM-I). CBM-I is a computerized procedure that targets HIB by offering patients many (unfamiliar) emotionally ambiguous scenarios on a computer followed by a reinforcement of benign instead of hostile interpretations (Mathews & Mackintosh, 2000). Meta-analytic evidence demonstrated favorable, moderate to large efficacy of CBM-I on anxiety- and depression-related biases (Hallion & Ruscio, 2011). Five additional studies demonstrated preliminary support for the efficacy of CBM-I on HIB, with moderate to large degrees (AlMoghrabi et al., 2018; Cougle et al., 2017; Hawkins & Cougle, 2013; Smith et al., 2018; Vassilopoulos et al., 2014). Moreover, recent evidence suggests that CBM-I may additionally augment the effectiveness of existing therapy protocols in affective disorders (Beard et al., 2019; Butler et al., 2015).