The myriad of factors that lead to PCS is beyond research. There is often a complete absence of information about prior concussions, sub-concussions, toxic exposures to the brain, other brain stressors, etc. Ability to process B-12 and other B vitamins can be a factor. Fatty acid levels also is an issue. Low fat diets can leave the brain susceptible to injury. Add to these issues the unknown impact of processed foods and additives and the matrix of complications is huge.

A concussion during a bout with depression will manifest different than a concussion absent any depression. Different hormone levels/balances also impact the damage left by a concussion especially in women. Blood glucose levels at time of concussion may also effect the symptom levels.

The research is all over the map.

Trying to compare notes is a futile effort. It only causes anxiety. Understanding the brain's intolerance to impact trauma is still grossly ignored. Maybe when a celebrity with the right connections suffers from PCS, there will be a openness to the issues. Gary Busy is ridiculed for his behavior when in reality, he has done extremely well despite his brain injury. Nobody cares to understand the underlying reason for some of his behaviors. Meatloaf gets applauded for his brain damaged antics that result from his drug abuse. Go figure.......