I've had Lyrica on prescription and a purchased one for Vyvanse. I noticed no bad interactions, no adverse effects.
I thought the synergy was great. At the time I was on 900mg of Lyrica/day and between 70-120mg of Vyvanse/day.
The Lyrica added a dimension of slight trippiness but not the kind psychedelics do. More of a subtle and detached, dissociative headspace.
The jitters and eventual angst, the comedown and most of the minor nuisances of Vyvanse were wiped clean. It also adds greatly to the
feeling of contentment. And the kind of grimy places stimulants can take you, Lyrica steered clear.
I really have nothing bad to say about the combo. I've tried small dosages, large, binges, responsible use - all with nothing but joy and pleasure.