Task: Classify the mental state of the tweeter based on the tweet, determining if it is 'neutral or no emotion' or characterized by any of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: It’s possible changing meds is best not done while under stress. Difficult to tell what part of despair is circumstantial, what is drugs.
This tweet contains emotions: 
sadness