Husband not as happy on lowered adderall dose?

My husband started on 10mg xr adderall 4 months ago after years of antidepressants that never worked. It has been really life changing for him and for our marriage. However, he lost a lot of weight at first and he was very skinny to begin with. So he has switched to the sr which makes him able to eat more. He has always had severe issues with his weight as far as wanting to be bigger but yet was so stuck in ADD and laziness that he refused to make himself anything to eat. At his last visit he asked for his dose to be even lower, 5mg from 10mg. I have noticed a pretty big change in him so far. He has less energy, wont look at me like he was in a loving, sweet way and is pretty snappy at times. He also will sit at the computer or on his iphone for HOURS playing stupid games. Could this be from the lowered dosage and that its not working as well for him? He just doesnt seem as happy at all since switching. I worry though because he would rather go back into depression than continue to lose weight. I take it as well and I know about the loss of appetite but I also know if I wanted too I could force myself to eat small meals. Plus there are tons of apps on the iphone to help with this. Anyone experience changes after lowering dosage?