Adderall misuse effects?

Increased risk of cardiac problems, neurological problems, seizures, depression, HBP, vomiting, muscle pain and abdominal pain, frequently misplaced and dangerous aggression, swelling of extremities, hallucinations, death.

Simply put, if you're not supposed to, don't use it.

From wikipedia...

"Tolerance, extreme psychological dependence, and severe social disability can occur when amphetamines are abused. The manufacturer warns against exceeding the prescribed dosage, injecting the drug, or insufflation of the drug. Prolonged high doses of amphetamines followed by an abrupt cessation can result in extreme fatigue and mental depression. Chronic abuse of amphetamines can manifest itself as psychosis, often indistinguishable from schizophrenia."