Question: How id Depechemood trained?
Answer: By multiplying crowd-annotated document-emotion matrix with emotion-word matrix. 
Alternative answer: researchers asked subjects to report their emotions after reading each article, multiplied the document-emotion matrix and word-document matrix to derive emotion-word matrix for these words, Depechemood simply creates dictionaries of words where each word has scores between 0 and 1 for all of these 8 emotion categories