It only takes three days usage of morphine to become addicted. This is true for unsubstantiated use. I have taken morphine in both long-term and quick acting oral forms over several years on and off, and have no addiction. I was advised by a pain clinic physician that morphine only becomes addictive in doses which reward the taking i.e. as long as the morphine is fighting pain, it is very unlikely to cause addicition. My doses were coontinually adjusted to retain a small element of discomfort (not even enough to prevent sleep) sufficient for me to tell it was comiing from the area normally giving severe pain. Of course, peoples' physiologies do differ - I know nothing about so-called addictive personanlities!