Long-term use of anti-depressants brings about an unique set of withdrawal symptoms when discontinued; much different than the repeated use of an opioid, such as heroin.
The methadone that is prescribed at clinics to help people that are trying to come off of heroin is usually in liquid form but is also available in tablets or in an injectable form.
Vicodin is prescribed in clinical settings to treat moderate to severe pain, usually associated with cancer, surgery, or serious injury.
Long-term alcohol abuse can potentially cause an overall reduction in brain size.