I have heard that a mental claim is easier to prove than physical. The sooner you start the process the better. The average claimant takes 2 years to get SSDI. Most people are denied the first time. You can also work while on SSDI. You can make up to $1040.00 per month for 9 months before you are reviewed and that 9months is any 9 months in 5 years I believe.