This will be about 1 page in length.
The first paragraph should start with a very broad statement on the general topic (i.e. opioid addiction). This is followed by a more specific introduction to the topic, followed by a sentence highlighting what we dont know. The last sentence should be your hypothesis,, which should directly relate to the previous sentence. How are you going to test that gap in the knowledge? This should take no more than 5-10 sentences.
Review of the necessary background information pertinent to understand your hypothesis. Another 5-10 sentences.
Restate hypothesis/research question and summarize what this knowledge will do for our greater understanding of the area. 2-3 sentences.