I also have ADHD, depression and GAD and I've personally--just personally, mind you--found that amphetamines and SSRI/SNRIs don't mix. Since my ADHD is more important to treat day to day I second the folks recommending you try Wellbutrin or another non-SSRI antidepressant. FWIW I take Buspar (buspirone) for my anxiety issues and it works well for me without interacting with my ADHD medication. Something to look into if it's available in your country, perhaps?