isla has moved to a large city to start her first job after college. she likes her new apartment and her new work colleagues, but she cannot seem to shake feelings of sadness. over time, she begins to sleep more and eat less. even playing with her dog seems less fun than it used to be. isla calls home to ask her father’s advice. he says that when he was her age, he went through the same feelings for about a year. he said he found a physician to work with that helped him use medication properly to balance out his mood. how does each of the following concepts apply to isla’s current situation?