Inclusion Criteria:

• Female aged 18 to 55 years and regularly menstruating.
• Meets DSM-IV criteria for unipolar major depression.
• Insomnia severity index score > 10.
• Hamilton Anxiety scale score > 15.
• Hamilton Depression scale score > 17.
• Capable of providing informed consent.
• Has an established residence and phone.

Exclusion Criteria:

• Meets DSM-IV criteria for schizophrenia, schizoaffective disorder or other axis I or II diagnosis except co-morbid anxiety disorder and insomnia.
• Actively abusing substances or alcohol; or has met DSM-IV criteria for substance dependence in the past month.
• Pregnancy.
• Use of benzodiazepines or other sedative-hypnotics, beta blockers, calcium channel blockers, antidepressants, antipsychotic medications, lithium or other medication which in the opinion of the investigator could alter glutamate or GABA activity in the brain.
• A medical condition, which in the opinion of the investigator could possibly affect the individual's brain levels of Glu and GABA.
• Participation in a research protocol that included administration of medication within the past 3 months.
• Cigarette smoking.
• Subject has known allergic sensitivity to any of the study to escitalopram, eszopiclone or zopiclone.
• Clinically significant suicidal ideation or risk of suicide as evidenced by formulation of a plan or steps taken to act on those feelings.
• History of clinically significant hepatic impairment.
• Subject is taking a potent cytochrome p450 3A4 inhibitor medication (ritonavir, nelfinavir, indinavir, erythromycin, clarithromycin, troleandomycin, ketoconazole, itraconazole) and is unwilling or it is clinically contraindicated to stop the medication.