A large number of mental illnesses may cause sleep problems such as insomnia or hypersomnia.
These include adjustment disorders, bipolar disorder, generalized anxiety disorder, panic disorder, personality disorders, schizophrenia and somatoform disorders.

People with sleep disorders that are associated with mental illness are likely to display two sets of symptoms. The first set of symptoms is related to the mental disorder itself.

The second set of symptoms is related to the sleep problems and includes fatigue, increased anxiety at bedtime and difficulty concentrating throughout the day.

So is there close relationship between the fatigue and sleep?
what do you think?