Can ADHD meds cause nerve damage? Ie numbness in fingers and joints, neck/shoulder tenseness, crippling sciatic nerve pain. Are these all related?

No. Stimulants can . Constrict blood vesselsraise blood pressure (usually by 5-6 mm hg) & ? pulse (usually by 5-6 beats/minute), but they don't cause impingement of nerve roots with numbness, tingling & pain in the areas served by specific nerves. See your primary care to initiate evaluation for the cause of your symptoms.