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Association between developmental milestones and age of schizophrenia onset: Results from the Northern Finland Birth Cohort 1966.

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Whittier, Anjalene 
Wagner, Adam P 
Veijola, Juha 
Jääskeläinen, Erika 


We investigated relationships between early developmental milestones, schizophrenia incidence and variability in its age at onset. We hypothesized that the period of risk for schizophrenia would be longer for those with later development. The Northern Finland Birth Cohort 1966 was followed until 47 years of age, and those members diagnosed with schizophrenia or any other non-affective psychoses identified. Latent profile analysis was used to classify people into homogenous classes with respect to developmental milestones, and subsequently survival analysis explored relationship between classes and age of schizophrenia onset. Results suggest that 4-classes (early, regular, late, and extra late developers) can be identified, but due to few cases in one class (n = 93, <0.01% of 10,501), only 3 classes (early, regular, late) could be meaningfully compared. Schizophrenia incidence until 47 years of age differed systematically between classes: late developers had the highest cumulative incidence (2.39%); regular were intermediate (1.25%); and early developers had the lowest incidence (0.99%). However, age at onset and its variability was similar across classes, suggesting that our hypothesis of a wider 'window' for schizophrenia onset in late developers was not supported.



Age at onset, Developmental milestones, Non-affective psychoses, Schizophrenia, Age of Onset, Cohort Studies, Developmental Disabilities, Female, Finland, Humans, Incidence, Male, Middle Aged, Schizophrenia

Journal Title

Schizophr Res

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Elsevier BV
National Institute for Health Research (NIHR) (via Cambridgeshire and Peterborough NHS Foundation Trust (CPFT) (unknown)
Wellcome Trust (201486/Z/16/Z)
Cambridge University Hospitals NHS Foundation Trust (CUH) (BRC 2012-2017)
Medical Research Council (MC_PC_17213)
MQ: Transforming Mental Health (MQDS17\40)