I can’t provide you with any specific anecdotal evidence about whether or not stress caused a specific effect. However, the doctor who prescribes my ADD meds has asked me when I said a particular med hasn’t worked for me, whether or not I had experienced any rise in stress level related to home or work. So I believe this must be a possibility. Incidentally, my response was that my life is always crazy so no not really 
But I suppose there is also the possibility that your body has gotten used to the dose and may require adjustment. There are lots of threads here related to that.
REPORT ABUSE