Quebec is the first province/territory to not fully exempt the Registered Disability Savings Plan.  Quebec has amended the Individual and Family Assistance Regulations to include the Registered Disability Savings Plan as an exempt asset, but has only partially exempted any income coming out of the plan.  

So, if you reside in Quebec and you set up an RDSP, it can grow to an unlimited amount without affecting your Disability Benefits.  Unfortunately, payments from the plan have been only partially exempted from affecting provincial disability benefits.  You are allowed to withdraw $300 in income a month for an indvidual adult, and $340 in income a month for a couple, and your disability benefits will not be affected.  Anything above this threshold will be considered income and may disqualify or cause funds to be clawed-back from current benefits.

Section 111 – (29) lifetime payments made for the benefit of an adult from a registered disability savings plan, up to a maximum of $300 per month for an independent adult or a family composed of only one adult and $340 per month for a family composed of 2 adults;

To view the Regulations you can visit:

http://www2.publicationsduquebec.gouv.qc.ca/dynamicSearch/telecharge.php?type=3&file=/A_13_1_1/A13_1_1R1_A.HTM