Neurobiological Effects of Light on MDD

The primary study objective is to observe/measure the circadian pattern of sleep, Cortisol and Melatonin in MDD subjects and Control subjects. We will also assess if controlled exposure to light in MDD subjects (post-partum females, non- post-partum females and males) will change these parameters using light glasses. In addition to the biological outcome measures (sleep, cortisol and melatonin) we will also monitor sleep and depressive symptoms in the research subjects for the duration of the protocol.

In this study we will collect baseline hormone data and clinical data along with assessing light exposure using a Daysimeter in MDD participants and control subjects. We will collect baseline Daysimeter data for 5 days and then collect cortisol and melatonin levels in both MDD subjects and Control Subjects. Control subjects will complete the study following the sample collection. MDD participants will then have a light intervention (sham or active).

Following the Daysimeter and hormone data collection, MDD subjects in each group will be randomly assigned into a non-treatment group or treatment group. While continuing to wear the Daysimeter, all MDD subjects will wear assigned glasses for 2 hours prior to bedtime. The subject will choose the bedtime hour and try and consistently wear the glasses at the same time throughout the study. Subjects will then wear the assigned glasses in the am upon waking for 1 hour. Following 7 days wearing the assigned glasses MDD subjects will repeat the sample collection for Cortisol and Melatonin

Eligibility Criteria:
Inclusion Criteria:

1. Able to provide informed consent before beginning any study-specific procedures
2. Male and female patients at least 18-60 years of age
3. Women with reproductive potential must have a negative pregnancy test;
4. Meets DSM-IV criteria for Major Depressive disorder
5. Hamilton Depression Rating Scale total score of 15 or greater
6. Negative Drug screen for drugs of abuse
7. No sleep altering medications, including herbal preparations. If subjects previously taking any of these medications, they need to be 1 week off of medications before starting the study.
8. If currently on SSRI, subjects must have been on them for 6-8 weeks.
9. PSQI of \>5 and without sleep difficulties unrelated to the depression

Exclusion criteria:

MDD subjects will be excluded if:

1. Subjects with a comorbid current primary Axis I disorder of OCD, Eating disorder or any non-anxiety related Axis 1 diagnosis.
2. Subjects who meet DSM-IV criteria for substance dependence confirmed by the SCID, for any substance except nicotine, within 3 months of screening.
3. Subjects who meet DSM-IV criteria for substance abuse within 3 months of screening.
4. Subjects with positive urine toxicology screen for illicit substances of abuse (aside from cannabis, if patient not abusing and agrees to stop use).
5. Subjects with a history of clinically significant cardiac, renal, neurologic, cerebrovascular, metabolic, or pulmonary disease, or other disease or clinical findings that are unstable, or that in the opinion of the investigator, would confound biological assessments.
6. Female subjects who are pregnant or who are breastfeeding or planning to become pregnant during the study.
7. Subjects who, in investigator's opinion, would be non-compliant with the study procedures
8. Subjects with current psychotic symptoms (delusions or hallucinations).
9. Existing sleep problems unrelated to the depression
10. Potential study subjects who are actively suicidal

Healthy Volunteers must fulfill all of the following inclusion criteria:

1. Able to provide informed consent before beginning any study-specific procedures
2. Not meet a current or lifetime DSM-IV Axis I disorder

2) Male and female patients at least 18 years of age 3) Women with reproductive potential must have a negative pregnancy test; 4) Medication free, including herbal medications 5) Negative drug screen for drugs of abuse. 6) PSQI of \< 5

Healthy volunteers will be excluded if:

1. A current or lifetime DSM-IV Axis I disorder.
2. A positive urine toxicology screen for illicit substances of abuse (aside from cannabis, if not abusing and agrees to stop use).
3. A history of clinically significant cardiac, renal, neurologic, cerebrovascular, metabolic, or pulmonary disease, or other disease or clinical finding that is unstable or that, in the opinion of the investigator, would confound biological assessments.
4. Females who are pregnant, breastfeeding or planning to become pregnant during the study.
5. People who, in investigator's opinion, would be non-compliant with the study procedures.