Schizophrenia is a complex, chronic, and severe brain that interferes with a person's ability to think clearly, manage emotions, make decisions, and relate to others. Nowadays it affects approximately 1% of all adults globally. The word schizophrenia comes from the Greek word skhizein meaning "to split" and the Greek word phren meaning "heart, mind." The Swiss psychiatrist, Eugen Bleuler (1857-1939), coined the term Schizophrenie in 1908. However, schizophrenia does not imply a "split personality" or "multiple personality disorder"—a condition with which it has been confused in public perception. Experts say schizophrenia is probably many illnesses masquerading as one. Research indicates that schizophrenia is likely to be the result of faulty neuronal development in the brain of the fetus, which later in life emerges as a full-blown illness. As of today there is no physical or laboratory test that can absolutely diagnose schizophrenia. Clinical diagnosis of schizophrenia is based on a person's observed behavior and self-reported experiences. Symptoms of schizophrenia typically come on gradually, beginning in young adulthood and lasting a long time, and they may vary, depending on the individual. Some may hear voices that are not there. Some may be convinced that others are reading their minds, controlling how they think, or plotting against them. This can distress patients severely and persistently, making them demotivated, withdrawn, and frantic. Others may find it hard to make sense of what the patients are talking about. In some cases, they may spend hours completely still, without talking. On other occasions they may seem fine, until they start explaining what they are truly thinking. The effects of schizophrenia reach far beyond the patient. Families, friends, and society are affected too. A sizable proportion of people with schizophrenia have to rely on others, for they are unable to hold a job or care for themselves.