Childhood and Adolescent Schizophrenia and Other Early-Onset Psychoses

Children and adolescents can have a variety of psychotic disorders from acute and transitory psychoses to chronic ones, such as schizophrenia. Their psychotic symptomatology, however, can also be the consequence of an organic cause or druginducted. Comparing to adolescence and adulthood, psychotic disorders in childhood seem to occur more rarely, which can be explained by lower incidence and diagnostic problems hallucinations and delusions in children are quite difficult to recognise (Turk et al., 2007). While schizophrenia is a very rare disorder in childhood, it becomes increasingly common during adolescence. It is actually the most frequent psychotic disorder in the age group of more than 12 years. This is the reason why this chapter will discuss schizophrenia in greater detail, highlighting possible difficulties a therapist can face during a diagnostic process. Some of these diagnostic difficulties will also be emphasized by the case report describing a metabolic disease which can mimic schizophrenia symptoms. Even though childhood and adolescent schizophrenia lie on a continuum with schizophrenia in adults and the same diagnostic criteria are valid no matter the age group, there are special difficulties in applying the adult criteria to children. Symptoms at an early stage are less specific and in addition show remarkable overlap with a number of developmental disorders. So, diagnosing schizophrenia in children or adolescents could be a much harder task than diagnosing adults. In childhood and adolescence, schizophrenia most often has a slow and insidious onset with many precursors in the shape of developmental, cognitive and emotional symptoms or retardation. None of these precursors is schizophrenia-specific, therefore it is striking to see the number of children and adolescents with schizophrenia that seem to be multidimensionally impaired. The fact is that schizophrenic psychoses are a very heterogeneous group of disorders. Consequently, it is difficult to find a unique etiology. Studies in recent years have focused on the neurobiological and neurodevelopmental approaches, including genetics, and have produced interesting results which have not been yet integrated into conclusive and convincing theory of schizophrenia (Remschmidt, 2001). The prognosis of early-onset schizophrenia is worse than schizophrenia that starts in adulthood, hence early recognition and treatment is crucial. Children and adolescents with any psychotic disorder, especially with schizophrenia, thus require a broad,