N the summer, Theresa feels great. She exercises, has a lot of energy, and loves life. By the middle of winter, she is feeling discouraged and has little energy. Once spring comes, she feels better again. Theresa is probably suffering from:

Theresa could be suffering from seasonal affective disorder, it usually occurs during seasons that has short days such as the seasons winter and fall. During these seasons, a person who suffers from this usually change their mood where in they show a symptoms of a person who has depression, after these seasons pass, it goes away and they are back to their usual mood, where in they could also show a happy and energetic mood.