hi. im coming to you on the behalf of my girlfriend who is 20. she deals with anxiety and uses the word depressed a lot. things that get her in these moods seem simple and not worthy of attitude/stress to me. its like if things dont go the exact way that she plans them then she shuts off and goes into all the pessimistic thoughts in her head.
Degree understand your concerns went through your details. I suggest you not to worry much. I am sorry to tell you that your girlfriend is a victim of her own negative thinking, as you have suggested. Her problem is disappointment and not depression. Her second problem is her idleness and obsessive thoughts. Disappointment from unforeseen life events do produce symptoms like sadness, inactivity, loss of appetite, thirst, loneliness etc.  You know well Idle mind is devils workshop. Idle mind always goes towards negative thinking and in that process most of the thoughts become obsessive. Her problem clearly is obsession or obsessive thinking. She needs expert intervention. She needs counseling and psychotherapy. I shall provide her with the required counseling and psychotherapy techniques online, to overcome these problems. Please describe the whole problem in detail and post a direct question to me. Hope this answers your query. Available for further clarifications. Good luck.