Many of us struggle with sleep issues and after months or years of it, there is a profound effect on our health. For those of us dealing with PTSD, depression or any other health problems really, lack of sleep will most definitely inhibit our progress to get better.
Here is an article which outlines many of the effects of sleep deprivation. I encourage you to have a good read of it.
Sleep is a core function of the body to help keep us healthy, both physically and mentally.