[weed]
That is extremely interesting about the sleep part, I asked the question as a good friend has early stages of dementia at a young age, they have given up getting stoned hoping it will help, but like you have irregular sleep, waking up after just 4 hours sleep plus having vivid dreams or nightmares.
Perhaps having a smoke or cookie in the evening might help them sleep better.
weed does change REM (dream) sleep, it delays its onset and there is less of it. having a proper balance of REM vs other sleep phases is important to cognitive abilities and and physical energy.
so if that person has sleep issues related to wacked out sleep cycles weed could get those sleep cycles nearer to normal.
Again thanks for your input vapourminer perhaps an evening smoke would be beneficial for them rather than outright abstinence. Sleep is important for them as a poor nights sleep results in worsening dementia symptoms the following day.