Sentiment analysis, especially for long documents, plausibly requires methods\ncapturing complex linguistics structures. To accommodate this, we propose a\nnovel framework to exploit task-related discourse for the task of sentiment\nanalysis. More specifically, we are combining the large-scale,\nsentiment-dependent MEGA-DT treebank with a novel neural architecture for\nsentiment prediction, based on a hybrid TreeLSTM hierarchical attention model.\nExperiments show that our framework using sentiment-related discourse\naugmentations for sentiment prediction enhances the overall performance for\nlong documents, even beyond previous approaches using well-established\ndiscourse parsers trained on human annotated data. We show that a simple\nensemble approach can further enhance performance by selectively using\ndiscourse, depending on the document length.\n