The major reasons marriages end in divorce are pretty well documented. In her article, 5 Common Reasons Marriages Fail (& How to Keep Yours Strong), Michelle Boudin writes that divorce attorney, Libby James, cites five common causes for divorce cases: Attrition – growing apart Mental health issues – narcissism, depression, bi-polar issues, etc. Alcohol and Substance Abuse – which puts strain on the relationship emotionally, financially, and sometimes physically. Financial Iss