Hey there, SH - Brain injury (even just concussions) increases your risk for depression. Depression, in my opinion, often leads to affairs (because that dopamine "high" of infatuation temporarily relieves the depression).
If parts of your brain aren't working quite as well as they ought, it is IMPERATIVE that you keep regular hours, get a good night's sleep every night, eat properly, avoid all alcohol.
Also, know that sometimes brain injury can result in pituitary hormone deficiencies, leading to low growth hormone, or low testosterone, or low thyroid. Ask your doctor for blood tests to rule this out.
My husband had 6 concussions in 8 years - but he thinks I am the reason he's unhappy. Grrrrrr....
