Discussing the optimal amount of sleep someone should get each night can be challenging, and the conversation differs based on the problem the patient presents to me with. In those who tend to get too little sleep, they usually report excessive daytime sleepiness or fatigue. I explain that the amount of sleep someone needs can not be altered and that the patient should get as much sleep as needed to feel rested. Sleep deprivation, whether voluntary or from a sleep disorder, can affect mental and physical health.
On the other hand, for patients with primary insomnia, focusing too much on sleep duration or attempts get the coveted 8 hours per night often fuels the insomnia. Most insomniacs are not as sleep-deprived as they think. Plus, the behavioral treatments I use will produce a temporary sleep-deprived state. I use that built up sleep pressure to overcome patients' insomnia.
In other words, the message to my patients about sleep duration can be contradictory at times. Getting too little sleep can be dangerous, even in the short term. But for some with insomnia, focusing on the perceived consequences of insomnia often make the insomnia worse. For these patients, putting less emphasis on sleep and sleep duration can actually help them sleep better.