Lipopolysaccharide (LPS) Challenge in Depression

Exclusion Criteria

• •Pregnancy
• •Previous history of fainting during blood draws.
• •Medical Conditions:
• •A history of a head injury with loss of consciousness.
• •Presence of co-morbid medical conditions not limited to but including cardiovascular (e.g., history of acute coronary event, stroke) and neurological diseases (e.g., Parkinson's disease), as well as pain disorders.
• •Presence of co-morbid inflammatory disorders such as rheumatoid arthritis or other autoimmune disorders.
• •Presence of an uncontrolled medical condition that is deemed by the investigators to interfere with the proposed study procedures, or to put the study participant at undue risk.
• •Presence of chronic infection that may elevate pro-inflammatory cytokines.
• •Presence of an acute infectious illness or receipt of a vaccination in the two weeks prior to an experimental session.
• •Psychiatric Disorders:
• •Current severe suicidal ideation or attempt within the past 12 months.
• •Psychosis
• •Bipolar disorder
• •Substance abuse or dependence within the previous 6 months
• •Age of onset of depression \>40 years
• •Contraindications for MRI:
• •Severe claustrophobia
• •Bodily implants of unsafe paramagnetic materials such as pace-makers and aneurysm clips.
• •Medications:
• •Current and/or past regular use of hormone-containing medications (excluding contraceptives)
• •Current use of non-steroid anti-inflammatory drugs that is deemed by the investigators to potentially confound the results of the study
• •Current and/or past regular use of immune modifying drugs that target specific immune responses such as TNF antagonists
• •Current use of analgesics such as opioids or history of addiction to opioids or other analgesics
• •Current and/or past regular use of cardiovascular medications, including antihypertensive, antiarrhythmic, anti-anginal, and anticoagulant drugs (does not apply where medications are taken for different purpose e.g. anti-hypertensives for migraine).
• •Evidence of recreational drug use from urine test.
• •Lifetime use of methamphetamine
• •Health Factors:
• •BMI \> 35 because of the effects of obesity on pro-inflammatory cytokine activity
• •Clinically significant abnormalities on screening laboratory tests
• •Abnormal EKG
• •In addition, participants who on arrival to the study, show any of the following symptoms will not be allowed to complete the study:
• •1. screening supine systolic blood pressure \>140 mmHg or \<100 mmHg
• •2. screening supine diastolic blood pressure \>90 mmHg or \<60 mmHg
• •3. 12-lead EKG demonstrating a PR interval \> 0.2 msec, QTc \>450 or QRS \>120 msec If the QTc exceeds 450 msec, or QRS exceeds 120 msec, the EKG will be repeated 2 more times and the median value will be used
• •4. pulse less than 50 beats/minute or greater than 100 beats/minute
• •5. temperature greater than 99.5F.
• •Non-English speaking participants:
• •The majority of the assessments proposed for this study have not been translated from English, thus, non-English speaking volunteers will be excluded.