Can you become addicted to dexedrine (dextroamphetamine) if i take it 5 times a week for a year?

Depends; not likely: If you use Dexedrine (dextroamphetamine) to treat adhd regularly at the same dose, whether 5 or 7 days a week, you will not become addicted. Addiction occurs when someone needs higher and higher doses to achieve the same desired effect, which is most uncommon when treating adhd. You will find that your adhd symptoms come back when you stop the medication, but that is not additiction, it's lack of sustained benefit.

If recreational: If you are taking without purpose it is hard to stop any medication.

Yes: Any medications that alters brain chemicals has a potential for withdrawal symptoms - with Dexedrine (dextroamphetamine) it would be mental withdrawal that would be troublesome.