1) Prisons in the UK are struggling to meet the needs of drug and alcohol dependent inmates, with 62% of new prisoners having a drug problem. 2) Treatment programs focus on rehabilitation through assessing inmates, drug treatment programs, education, and building self-esteem, though resources and approaches vary between prisons and regions. 3) Methadone substitution is controversial as it is addictive and visibility damages employment prospects, though it reduces withdrawal; controlling drug flow into prisons is difficult due to smuggling.