This allows us to wake refreshed and able to begin each new day alert and able to concentrate. If there is excessive worrying or anxiety about unresolved issues we will dream more and therefore have less slow wave sleep which is the resting sleep and we can then wake tired despite feeling we have been asleep for 8 hours. Research into dreaming suggests that depression can develop through poor sleep patterns due to introspecting and worrying which then creates fatigue and more introspection as we feel unable to take part in our normal activities.