Research:Is there a correlation between sleep and mood?

I would want to do an experiment to test out whether there is a correlation between sleep and mood. So does the amount of sleep that a person gets affect his/her emotions? In order to carry out this experiment, I would need 2 groups of randomized participants with similar occupations and work schedules. One group would be the group that gets at least 8 hours of sleep per day for 1 week, while the other group would only get no more than 5 hours of sleep per day for 1 week. To do this experiment, I would need the participants from both groups to keep a journal on the exact amount of hours of sleep they get each day for the week and also their mood on that following day. The amount of sleep hours would be the independent variable and the participant’s mood would be the dependent variable. After a week, I would read the journals of all the participants in both groups and record the results. Then, I would compare the results and try to draw a conclusion based on the results. I believe that the group that gets at least 8 hours of sleep each day will be happier than the group that gets no more than 5 hours of sleep per day. Lack of sleep often make people frustrated and moody. The result of this experiment would be great evidence for parents to use to advice their children to sleep earlier at night. It would be beneficial for a lot of young adults because the result would let them understand the importance of having enough hours of sleep at night. The difficulty of designing this experiment is to think of how to keep away the confounding variables from affecting the results of my experiment. People with different jobs or school workloads might have different mood to begin with and I would not be able to distinguish the effect of sleep on mood from the participants’ personal issues from their everyday life, hence in order to lower the effect of the confounding variables on the results of my experiment, my selected participants are people with the same occupations and work schedules.