system
Given the following post, respond as if you're commenting on Reddit:
human
Could we scan the brain to diagnose conditions like autism and ADD?


I was just thinking about conditions such as ADD, ADHD, Autism and so on. My sons doctor was saying there is no scans etc. that could to be done see if he has said conditions it’s all based on observed behaviours. Do you think we will ever understand the brain enough to have tests like we do for a broken bone for such conditions?
gpt
Someday probably, but we currently don't understand the functional properties of unaffected brains well enough to reliably determine by a scan alone what is or isn't within the range of normal variation. 

Additionally, these scans would be done by a functional MRI machine (basically a recording of brain activity; a regular MRI is more like a soft-tissue XRAY). Unfortunately fMRI machines with high enough resolution to see that kind of detail are few and far between, and fantastically expensive, so that's not a diagnostic route that will be available to most people.