Schizophrenia is a mental disorder often characterized by abnormal social behavior and results in failure to recognize the realities. Common symptoms include false beliefs (negative thoughts), unclear or confused mind, auditory hallucinations, reduced social engagement, emotional expression, and inactivity in some cases. It's diagnosis is very difficult because it's based on observed behavior and the person's reported complaints. Genetics and developmental, as well as psychological and social processes, appear to be important contributory factors of schizophrenia. Some recreational and prescription drugs also known as schedule 3-4 drugs, appear to cause or worsen symptoms. The many possible combinations of symptoms have triggered debate about whether the diagnosis represents a single disorder or a number of separate syndromes.