Mental health drugs prior to signing up for Marines?

My little brother has recently signed up for the US Marines and is now in boot camp. While he was growing up he was diagnosed with ADHD and depression. He took both Adderol and Prozac (generic) while growing up. When he signed up for the Marines he neglected to divulge this information to them. Now the recruit doctor is calling my family and family doctors trying to get information. What is going to happen to my brother? Will he be discharged? Given jail time? Please give me any info you can.