Task: Categorize the tweet's emotional expression, classifying it as either 'neutral or no emotion' or as one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that reflect the tweeter's state of mind.
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