Hallucinations are common and often stressful experiences, occurring in all sensory modalities. They frequently complicate many disorders or situations, such as Parkinson's disease, schizophrenia, hearing or vision loss, intoxications and delirium. Although psychoeducation, coping techniques and psychotherapy may be broadly applicable, they do not address a specific underlying brain mechanism. Pharmacotherapy may effectively alleviate hallucinations if the corresponding mechanism is present, whereas in its absence, may only cause harmful side effects. Therefore, pharmacotherapy needs input about underlying brain mechanisms.VCathens18