Schizophrenia is a mental disorder first identified in 1887 that causes hallucinations, delusions and disorganized thinking. It has strong genetic influences, with a 10% chance of developing it if a close relative has it. Physical signs include a blank facial expression while mental signs include hallucinations, delusions and disorganized speech. Emotionally, those with schizophrenia have reduced ability to feel pleasure and may feel detached. Treatment involves newer antipsychotic medications that can help control positive symptoms.