Undoubtedly it's very important and recommended across the board by the specialists who know what they're talking about, but I'm wanting to know if failure to rest leads to permanent deficits in the healing process, rather than just delays.

The majority of sources I've found say that neglecting to rest will simply prolong recovery, but they're all pretty vague. I've also seen at least one site that said failure to rest would indeed lead to permanent damage that might not have been incurred otherwise.

So what's the general understanding here? If someone suffers a concussion and simply resumes their everyday life with stress, exercise, light exposure, study, television, video games, etc. Are they putting themselves at risk of never healing as optimally as they might have otherwise, or will they simply reach their maximum point of recovery after say, 4 months instead of 2 with proper rest?