Chapter 1 General introduction Chapter 2 Warning signs prior to aggressive behaviour in child psychiatric units Chapter 3 Kennedy Axis V: clinimetric properties assessed by mental health nurses Chapter 4 Aggressive behaviour, hostility, and associated care needs in patients with psychotic disorders: a 6-year follow-up study Chapter 5 Hostility and aggressive behaviour in first episode psychosis: results from the OPTiMiSE trial Chapter 6 Efficacy of typical and atypical antipsychotic medication on hostility in patients with psychosis-spectrum disorders: a review and meta-analysis Chapter 7 Summary Chapter 8 General discussion References Samenvatting Dankwoord Curriculum Vitae CHAPTER 1 General Introduction CHAPTER 1 GENERAL INTRODUCTION