Early-Onset Schizophrenia Definition
Early-onset schizophrenia (EOS) is defined as onset of disease before 18 years of age, with very-early-onset schizophrenia (VEOS) defined as onset before 13 years of age. 1, 2, 3
Standardized Terminology
The American Academy of Child and Adolescent Psychiatry established this nomenclature to avoid ambiguity, as the older term "prepubertal schizophrenia" was inaccurate when puberty is defined by age rather than physical development. 1
Epidemiological Context
Understanding the rarity of early onset is critical for diagnostic scrutiny:
- Onset before age 13 is extremely rare, with only 4 cases younger than 13 years and 28 cases younger than 15 years identified in a 13-year Danish national study of all hospitalized youth with schizophrenia (n=312). 1, 2
- The youngest reported cases in the literature had onset at 3 years and 5.7 years of age, though diagnosis at such young ages requires extremely careful scrutiny. 1, 2
- The rate of onset increases sharply during adolescence, with peak ages of onset ranging from 15 to 30 years. 1
- VEOS occurs predominantly in males with ratios of approximately 2:1, though this ratio evens out as age increases. 1
Diagnostic Criteria Consistency Across Ages
The diagnosis in children and adolescents is made using identical DSM-IV criteria as in adults, regardless of age of onset. 1, 2, 3 This approach has been validated by research since DSM-III, which demonstrated the distinctiveness of childhood schizophrenia from autism and its similarity to adult schizophrenia. 1
Clinical Significance of Age Cutoffs
The age of onset has profound prognostic implications:
- Onset before age 12 is uniformly associated with worse disability at outcome. 2
- Onset before age 15 correlates with higher ratings of negative symptoms in adulthood. 2
- Onset before age 21 results in greater social impairment compared to later onset. 2
- Approximately 8% of patients with schizophrenia are diagnosed before age 18, and 18% experience their first symptoms before age 18. 4