The answer is yes. You are still able to claim your son as an eligible dependant due to his mental health issue.

• The additional amount for an eligible dependant 18 years of age or older is available under Canada Caregiver Credit.
• Note: If you are required to pay child support or have shared custody of the child, additional rules may apply.

• Another credit may apply for your son on TurboTax articles:

   A Guide to the Disability Tax Credit 

   How do I claim the disability tax credit?

If you require further assistance please contact our phone support team or contact us directly on Facebook or Twitter.