The neurodevelopmental hypothesis is supported by many studies which find a range of developmental delays and deviations which are considered indicators of prior adverse neurodevelopmental events. These include delayed early developmental milestones (walking, talking and toilet training), deficits in cognitive, behavioural and social functioning, and physical anomalies in brain structure and function and other minor physical structures such as dermatoglyphy.

We now go on to examine some risk proxies and factors.