What sort of disorder is co-codamol addiction?

Very common: Co-codamol (is a non-proprietary name used to denote a particular compound analgesic, a combination of Codeine phosphate and paracetamol (acetaminophen). Co-codamol tablets are used for the relief of mild to moderate pain when paracetamol or nsaids such as ibuprofen, Aspirin or Naproxen alone do not sufficiently relieve a patient's symptoms.

Narcotic addiction: It is an addiction to a narcotic. It occurs in about 10% of the population (just as other drug and alcohol addictions do).

Opioid Addiction: The Codeine metabolizes to morphine in your body to some extent. Hence, the addiction is to opiates sometimes improperly termed narcotics, which is a more general term.