Neurophysiological signature(s) of visual hallucinations across neurological and perceptual:and non-invasive treatment with physical exercise

Hallucinations are common and stressful in many psychiatric, neurologic and perceptual disorders disturbing daily life, and increasing mortality, while current treatment of hallucinations is far from optimal. In current clinical practice, treatment with medication is selected in accordance with guidelines for the underlying diagnostic entity, not on the underlying mechanism of hallucinations per se. Understanding the pathophysiological mechanism of (subtypes of) hallucinations may provide new opportunities for treatment and enable rational choice of pharmacotherapy in a personalized manner increasing treatment efficacy and safety. In part I of this dissertation, we found common neurophysiological mechanism(s) underlying visual hallucinations (VH) across disorders. Although the hypothesis of altered attention in VH is not new and has been proposed in several individual disorders, its neurophysiological signature(s) have never been investigated and compared as such across a variety of disorders. This dissertation shows that VH across disorders are quite similar with regard to an underlying neurophysiological mechanism. This finding may aid the discovery of treatment options that could effectively alleviate these hallucinations across disorders, as it suggests that treatment effective for VH in one disorder may be beneficial for VH in another disorder too. In part II of this dissertation, we found evidence for the efficacy of physical exercise (PE) as an add-on treatment for clinical symptoms in schizophrenia spectrum disorder, but also for quality of life, depressive symptoms, and cognitive impairment in the chronic brain disorders Alzheimer’s disease, Huntington’s disease, Multiple Sclerosis, Parkinson’s disease, Schizophrenia, and Unipolar Depression