My paper was just a brief overview of several causes of depression and several studies, not a collection of all possible studies on this issue. (personalityresearch.org)
There are several causes including ingestion of toxic substances, renal failure and electrical shock but the most common cause is severe dental disease. (safarivet.com)
This can be tricky because asthma can stem from several causes and treatment often depends on what is triggering the asthma. (sciencedaily.com)