Task: Identify the primary emotion conveyed in the tweet and assign it to either 'neutral or no emotion' or one or more of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best capture the tweeter's mental state.
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