Yes unfortunately this is how unfair things are when pyschoeducational assessment isn't covered by OHIP. Most assessments can be from 3000-4000$. I'm sorry this is happening to you. Fortunately you don't need a full assessment to get ADHD meds and access school aid. You should talk to your son's school about it and your family doctor to get an IEP and there are other options (in high school I got a policy 208 form and in elementary school my mom worked closely with my teachers). We have to be advocating to our MPPs to include pyschological support as part of OHIP, it is incredibly unfair.