 [ Symptoms ] what are the diseases what can cause multimodal hallucinations i know of dementia but what are the others  the person does not use drugs alcohol and does not it is not a cafeine overdosis [ Disease ] many physical and emotional disturbances can cause hallucinations according to health care the following are some of reasons that hallucinations may occur brain disorders including leisions and injuries sensory deprivation as seen sometimes in the blind & deaf emotional stress sleep deprivation mental illness as seen in schizophrenia alcohol withdrawl hallucinogenic drugs