The psychotic illness, for example schizophrenia or delusional disorder, may already have started at a young age.If schizophrenia has its onset in the middle or old age only, the term ’late-onset (or very-late-onset) schizophrenia-like psychosis’ is used.Psychotic symptoms may occur in association with a number of organic and psychiatric conditions.Depression, mania and deliriumMetabolic and endocrinological disordersNeurological diseases Memory diseaseCNS infectionsMedication, poisonings and drug overdosesWhen medication is started, the lowest possible dose is sought to avoid adverse effects.