Martijn van Teffelen

Chapter 7 162 provocation conditions. Specifically, psychopathic traits impact affective, whereas narcissistic traits impact cognitive dimensions. It may therefore be beneficial for people with psychopathic traits to put less emphasis on interventions that target affective dimensions of hostility, such as progressive relaxation. Along the same lines, for people with narcissistic traits it may be beneficial to focus treatment more on interventions that target cognitive aspects of hostility, such as CR and CBM-I. Altogether, offering a combination of interventions that aligns with individual trait-profiles may further increase effectiveness. CLINICAL IMPLICATIONS The results of the present work come with several implications for clinical practice. First, across four different studies, the current work suggests that hostile interpretation bias is a promising intervention target. Specifically, hostile interpretation bias was identified as a separate hostility dimension ( chapter 2 ) that is differentially impacted by situational factors and personality traits ( chapter 3 ). In addition, three different interventions (I-CR, CR and CBM-I) targeting hostile interpretations showed significant reductions on hostility complaints ( chapters 4 and 6 ). This shows that hostile interpretation bias is a valid, stand-alone concept within hostility that is therapeutically malleable. It also implies that hostile interpretation bias is a dimension that should not be underestimated in patients. Rather, hostile interpretation bias is a construct that should specifically be attended to. For example, even when a patient is not showing overt aggressive behavior it does not mean that these patients or the people in their environment are not burdened by the patient’s tendency to interpret situations in a hostile way. Second, findings in chapter 2 suggest that at present the construct and face validity of hostility measures is questionable. This implies that using a hostility instrument in clinical practice can lead to false conclusions. For example, a clinician intends to measure hostility aspects in a patient, in order to determine potential targets for intervention. If the clinician selects a hostility instrument containing cross-capturing items (as e.g., the AQ, as outlined above) this will negatively impact the risk of measuring the wrong construct and not detecting the changes (s)he aims to measure. Vice versa, measurement imprecision will inaccurately estimate levels of interpretation bias, affect, and affect potentially resulting in a wrong selection of interventions. Along the same lines, in chapter 6 it was shown that CBM-I impacts cognitive and behavioral, but not affective aspects of hostility. Using an instrument that intends to measure hostile behavior, but in reality, partially measures cognitive or affective dimensions of hostility may lead a clinician to falsely conclude that CBM-I is not effective. Thus similarly, using an instrument that intends to measure cognitive dimensions of hostility, but actually underestimates it may lead a clinician to falsely disregard CBM-I or (I-)CR as potential intervention.