Post-traumatic stress is far from the only possible outcome.In the wake of even the most terrifying experiences, only a small proportion of adults become chronically troubled.

【翻译】创伤后的压力远不是唯一可能的后果。即使在经历了最可怕的磨难之后，也只有一小部分成年人会长期受到困扰。

【分析】

Post-traumatic stress （主语）is （系动词）far from the only possible outcome（表语）. In the wake of even the most terrifying experiences（时间状语。意思是“在...之后”）, only a small proportion of adults （主语）become （系动词）chronically troubled（表语）.