- Both healthy controls and depressed participants will be required to be in good general health (as evaluated during Visit 1, including EKG) and to be 18-55 years of age. Depressed participants will be required to have symptoms of depression (i.e. a PHQ-9 score ≥10) and be unmedicated for at least 3 weeks (8 weeks for fluoxetine). Half the depressed participants (N=10) will be required to have a high-sensitivity C-Reactive Protein (CRP) score of ≥3 mg/L, and half the participants will be required to have a CRP score of ≤1 mg/L.