The diverse substance abuse treatment programs which are available to alcohol and drug addicted people in Angola can differ in several various ways. Quite a few substance abuse rehabilitation programs are conducted in a residential or inpatient facility, where clients reside the entire time they are in rehab which supplies a more conducive treatment environment. Others provide alcohol and drug abuse rehabilitation programs on an outpatient basis which allows for more flexibility, although outpatient centers may not be an appropriate substance abuse rehabilitation service for individuals in Angola who are having difficulties with serious addiction problems. Whether or not inpatient or outpatient alcohol and drug abuse rehab programs are chosen, there are varying amounts of time that people will be required to stay in the alcohol and drug rehabilitation center. For example, many short-term programs offer services for a month or less, while long-term programs will call for at least a 12 week stay.