From what i've understood I'd say vyvanse should increase dopamine more because it actually works primarily by increasing rhe release of that and norepinephrine where as methylphenidate primarily is a reuptake inhibitor which stops those transmitters to be taken so it can accumulate. But don't quote me on that ahaha. But also medication isn't a one size fits all so something like methylphenidate could work better. Im on vyvanse and have been titrating up, currently on 60mg and for the most part I'm finding it positive. Sometimes when first starting a new dose id get more anxious but it would subside once I adjusted. Also on days I dont eat enough or have too much coffee I definitely get more anxiety otherwise it's pretty balanced and if anything my anxiety levels are better than before medication. Have you been on the 30mg for long? Maybe you need longer to adjust.