"39 face and have a stronger reaction to words with negative meanings than people who do not have the disorder. Schizophrenia Schizophrenia affects approximately 1 percent of the population, or 2.2 million U.S. adults. Men and women are equally affected. The illness usually emerges in young people in their teens or twenties. Although children over the age of five can develop schizophrenia, it is rare before adolescence. In children, the disease usually develops gradually an d is often preceded by developmental delays in motor or speech development. Childhood - onset schizophrenia tends to be harder to treat and has a less favorable prognosis than does the adult - onset form. The symptoms of schizophrenia: There are many myths and misconceptions about schizophrenia. Schizophrenia is not a multiple or split personality, nor are individuals who have this illness constantly incoherent or psychotic. Although the media often portray individuals with schizophrenia as violent, in reali ty, very few affected people are dangerous to others. In fact, individuals with schizophrenia are more likely to be victims of violence than violent themselves. Schizophrenia has severe symptoms. A diagnosis of schizophrenia requires that at least two of t he symptoms below be present during a significant portion of a one - month period: delusions (false beliefs such as conspiracies, mind control, or persecution); hallucinations (usually voices criticizing or commenting on the person’s behavior); disorganized speech (incomprehensible or difficult to understand); grossly disorganized or catatonic behavior; and negative symptoms such as flat emotions, lack of facial expressions, and inattention to basic self - care needs such as bathing and eating. However, the p resence of either one of the first two symptoms is sufficient to diagnose schizophrenia if the delusions are especially bizarre or if the hallucinations consist of one or more voices that keep a running commentary on the person’s behavior or thoughts. The DSM - IV specifies additional criteria for a diagnosis of schizophrenia: occupational dysfunction, persistence of the disturbance for at least six months, exclusion of a mood disorder, exclusion of a substance - abuse or medical condition that causes similar s ymptoms, and consideration of a possible pervasive developmental disorder. The course of schizophrenia varies considerably from one individual to the next. Most people who have schizophrenia experience at least one, and usually more, relapses after their f irst psychotic episode. Relapses are periods of more intense symptoms of illness (hallucinations and delusions). During remissions, the negative symptoms related to emotion or personal care are usually still present. About 10 percent of patients remain sev erely ill for long periods of time and do not return to their previous state of mental functioning. Several long - term studies found that as many as one - third to one - half of people with schizophrenia improve significantly or even recover completely from the ir illness."