Sleep and well-being

Question 1

What are the two studies regarding sleeps effect on well being?
Sample size?
Method?
Results?

Answer 1

1. 100,000 Japenese/3722 UK uni students
2. slept 7-9 hrs, or less than 7, more than 7/ received digital CBT or none
3. if slept 7-9 hours had better mental health than less than 7 or more than 9/ reduction in anx and dep and PSYCHOSIS - specifically hallucinations, paranoia, INSOMNIA after 10 weeks