Child and adolescent onset schizophrenia

Schizophrenia is one of the most devastating psychiatric disorders to affect children and adolescents. Although extremely rare before the age of 10, the incidence of schizophrenia rises steadily through adolescence to reach its peak in early adult life.

An accumulating body of evidence now supports the view that schizophrenia in childhood and adolescence shows continuity with the adult form of the disorder at the levels of symptoms, clinical course and underlying neurobiology. Like other disorders of presumed multifactorial origin (e.g. juvenile rheumatoid arthritis and diabetes), the early onset form of schizophrenia appears to lie at the extreme end of a continuum of disease severity and genetic liability.

This section focuses on the similarities and differences, from both a clinical and neurobiological perspective, between child and adolescent onset schizophrenia and the adult form of the disorder. Special attention will be given to the following topics.

First, the historical development of the concept of schizophrenia in children and adolescents. Secondly, the clinical issues relating to the recognition, differential diagnosis and management of child and adolescent onset schizophrenia. Thirdly, the evidence from clinical and neurobiological studies for continuity between the childhood and adult onset forms of the disorder. Fourthly, the possible mechanisms and timing of events in brain development that may be responsible for the onset of schizophrenia in children and adolescents.

History

Evolution of the concept of schizophrenia in childhood and adolescence

Both Kraepelin and Bleuler believed that schizophrenia presented in a similar form, albeit more rarely, during childhood and adolescence. Kraepelin (1919) found that 3.5% of cases of dementia praecox began before the age of 10, with a further 2.7% arising between the ages of 10 and 15. Kraepelin also remarked that these childhood onset cases frequently had an insidious onset. Bleuler (1911/1950) suggested that about 5% of cases of schizophrenia had their onset prior to age 15. De Sanctis (1906) described a group of young children who exhibited catatonia, stereotopies, negativism, echolalia and emotional bluntening. De Sanctis viewed this condition as an early onset form of Kraepelin's dementia praecox, and coined the term 'dementia praecoccissima'. The twentieth century saw a shifting debate about how best to categorize schizophrenia in childhood.

The expansion and contraction of the concept of schizophrenia in childhood closely mirrored a similar debate concerning the boundaries of the adult form of the disorder. It also echoed the debate about how best to conceptualize and define depression in childhood, with the idea of age-specific symptomatology (developmental heterotypy) competing with the idea of applying unmodified adult diagnostic criteria to children (developmental homotypy).