Depressive and psychotic symptoms in schizophrenia:Focus on networks and treatment

Abstract

This thesis has two main aims. First, to review and increase knowledge concerning symptom interaction in patients with schizophrenia, with a specific focus on co-occurring depressive symptoms and its neural correlates in major depressive disorder (Part I and II). Second, to review and investigate different treatment aspects and outcomes in schizophrenia (quality of life, depressive symptoms and mortality) (Part III). In sum, both network studies showed the importance of depressive symptoms in the symptom networks of patients with schizophrenia and showed the stability of such a network structure. Although the network approaches has several issues of debate, it is a promising new way of thinking about psychopathology. The network approach is an example of a new conceptualisation of psychopathology as dynamic systems that change over time. Additionally, this view on mental illness facilitates a more transdiagnostic approach, in which emotion regulation should be an important target for future studies. Given the frequent co-occurrence of depressive symptoms in patients with schizophrenia, its centrality, its correlations with suicidality and influence on quality of life, it is highly important to adequately treat co-occurring depressive symptoms and episodes. Systematically following the provided treatment guide to treat depressive symptoms or episodes might be useful. Additionally, meta-analyses showed that schizophrenia patients who do not use antipsychotics have a higher mortality risk compared to patients that use antipsychotics. In a similar way, continuous use of clozapine was related to a lower mortality risk compared to patients using other antipsychotics