Childhood psychiatric disorders as anomalies in neurodevelopmental trajectories

I really like this paper from Shaw, Gogtay and Rapoport at the National Institute of Mental Health. They discuss the evidence for variations in developmental trajectories as a cause, or maybe just an identifier, of childhood psychiatric disorders.

This figure nicely illustrates their point. In the first example (A) they suggest that some children may be a little behind their peers in their development, but they still end up at the same point in the end. In example B the opposite is shown: a change in the speed of the trajectory. Here the pathological group has a much faster rate of change. And finally in example C the authors acknowledge that some disorders will have totally different developmental trajectories: here they show a flat line, but really it could be anything that has a different shape to the "normal" trajectory.

Their examples for each of the above are ADHD, childhood-onset schizophrenia (COS) and Down's syndrome respectively. The evidence for ADHD children ending up with similar looking brains to their peers when they reach adulthood lines up really well with the evidence that people tend to "grow out" of ADHD. It may be that as the ADHD trajectory converges on the "normal" trajectory the ADHD symptoms desist.

I like this paper because in the Bunge lab we're working on a very large longitudinal study of normal childhood development of reasoning skills, and this evidence really supports the motivation of fully understanding the meaning of "normal development". Hopefully in the future we can identify children who are not developing along with their peers and use brain imaging to guide interventions.

Childhood psychiatric disorders as anomalies in neurodevelopmental trajectories.

Shaw P, Gogtay N, Rapoport J.

Hum Brain Mapp. 2010 Jun;31(6):917-25.
Review. PMID: 20496382