Schizophrenia

Definition Schizophrenia is a mental disorder characterized by disruptions in thought processes, perceptions, emotional responsiveness, and social interactions. Although the course of schizophrenia varies among individuals, schizophrenia is typically persistent and can be both severe and disabling. Symptoms of schizophrenia include psychotic symptoms such as hallucinations, delusions, and thought disorder (unusual ways of thinking), as well as reduced expression of emotions, reduced motivation to accomplish goals, difficulty in social relationships, motor impairment, and cognitive impairment. Although symptoms typically start in late adolescence or early adulthood, schizophrenia is often viewed from a developmental perspective. Cognitive impairment and unusual behaviors sometimes appear in childhood, and persistent presence of multiple symptoms represent a later stage of the disorder. This pattern may reflect disruptions in brain development as well as environmental factors such as prenatal or early life stress. This perspective fuels the hope that early interventions will improve the course of schizophrenia which is often severely disabling when left untreated. Additional information can be found on the NIMH Health Topics page on Schizophrenia.

Age-Of-Onset for Schizophrenia Schizophrenia is typically diagnosed in the late teens years to early thirties, and tends to emerge earlier in males (late adolescence – early twenties) than females (early twenties – early thirties).1,2 More subtle changes in cognition and social relationships may precede the actual diagnosis, often by years.

Prevalence of Schizophrenia Precise prevalence estimates of schizophrenia are difficult to obtain due to clinical and methodological factors such as the complexity of schizophrenia diagnosis, its overlap with other disorders, and varying methods for determining diagnoses. Given these complexities, schizophrenia and other psychotic disorders are often combined in prevalence estimation studies. A summary of currently available data is presented here. Across studies that use household-based survey samples, clinical diagnostic interviews, and medical records, estimates of the prevalence of schizophrenia and related psychotic disorders in the U.S. range between 0.25% and 0.64%. 3,4,5

Estimates of the international prevalence of schizophrenia among non-institutionalized persons is 0.33% to 0.75%.6,7

Burden of Schizophrenia Despite its relatively low prevalence, schizophrenia is associated with significant health, social, and economic concerns. Schizophrenia is one of the top 15 leading causes of disability worldwide. 8

Individuals with schizophrenia have an increased risk of premature mortality (death at a younger age than the general population). 9,10,11,12 The estimated average potential life lost for individuals with schizophrenia in the U.S. is 28.5 years. 10 Co-occurring medical conditions, such as heart disease, liver disease, and diabetes, contribute to the higher premature mortality rate among individuals with schizophrenia. 10 Possible reasons for this excess early mortality are increased rates of these medical conditions and under-detection and under-treatment of them. 13 An estimated 4.9% of people with schizophrenia die by suicide, a rate that is far greater than the general population, with the highest risk in the early stages of illness. 9

Approximately half of individuals with schizophrenia have co-occurring mental and/or behavioral health disorders. 14

Financial costs associated with schizophrenia are disproportionately high relative to other chronic mental and physical health conditions, reflecting both “direct” costs of health care as well as “indirect” costs of lost productivity, criminal justice involvement, social service needs, and other factors beyond health care.5