Slow-wave Sleep Deprivation in Depression

Inclusion Criteria: * Among the inclusion criteria will be: * age range 18-35 years * right handedness * major depressive disorder according to DSM-IV (Diagnostic and Statical Manual-Revision 4) criteria (as determined by the Structured Clinical Interview for Diagnostic and Statical Manual-Revision 4), with Hamilton Rating Scale for \*Depression scores of at least 18 on the first 17 items * no psychotropic medications for at least 4 weeks * no joint and muscular di * normal hearing * regular bedtimes and sleep duration, no time zone shifts in the last three weeks. Exclusion Criteria: * Diabetes requiring insulin treatment * A serious heart disorder or subjects who have had a heart attack within the last 3 months * A diagnosis of cancer in the past 3 years and/or has active neoplastic disease * Clinically significant abnormalities on pre-study physical exam or physician evaluation * Subjects who meet DSM-IV (Diagnostic and Statical Manual-Revision 4) criteria for alcohol/drug abuse problems within the last six months or are currently using illegal drugs. * Female subjects of child-bearing potential who are pregnant or planning to become pregnant. * Women of child-bearing must be practicing a medically acceptable form of birth control. * Women of childbearing potential will be questioned about pregnancy status and form of birth control to be used at each visit. * Women who are unsure of their pregnancy status will be given a urine pregnancy test. * Subjects taking investigational medications * Subjects currently undergoing electroconvulsive therapy (ECT) or therapeutic transcranial magnetic stimulation (TMS). * Subjects who regularly perform night or late evening shift work (e.g. - "second" or "third" shifts) or have had travel with time zone shifts \>3h in the last 3 weeks