College students are likely to get depression if they're close with their family and have been away from home for quite some time. Being on their own and not having parents or siblings to help them through the day is tough, especially if they're in another state or country. Stress from the loads of assignments they have builds up and makes it easy for them to feel helpless and depressed. Being more social with people they've never met before is also difficult; they are most likely content with the friends they already have back home and may isolate themselves within their studies and not talk to barely anyone. It's difficult to transition from having everything provided for you by your parents to providing for yourself, taking yourself where you need to go, and being completely in charge of your life. Sometimes the teen will have difficulty facing this reality and become depressed.
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"Social Causes of Depression." Great Ideas in Personality--Theory and Research. Web. 21 Nov. 2010. <http://www.md-phc.com/puntil/secausesof.htm>.