1) Situational or transitional: This is when someone is forced into homelessness because of uncontrollable circumstances such as loosing a job, important material lost, lost of main breadwinner(father, husband, wife) etc.
2) Episodic or cyclical: This is when a person repeatedly falls in and out of homelessness. This often happens with drug addicts and with people experiencing mental health issues. The person might live episodes of severe depression cyclical way and fall back in homelessness when these occur. Same for someone with drug abuse issues. The person may be able to stop consuming for certain periods of time and get off the street, while being at high risk of homelessness all the time.
3) Chronic: This is when an individual is in the street for a long period of time and very few or no resources are at their disposition to modify their situation. Often, these people will suffer from mental health issues. They wont have the ability to modify their situation without the support of others. It is very rare that someone will be homeless all of his or her life on a voluntary basis.
Source: Réseau solidarité du Québec (2006).Pour une politique en Itinérance.