This is an open-label, dose-escalation pilot study. Prospective participants will initially undergo a blinded placebo challenge to assess his or her ability to self-administer drug. A total of sixteen subjects, will be enrolled in one of two study arms (eight subjects per group), depending on whether or not they are receiving concurrent treatment with an SSRI. The first 8 patients enrolled will receive subcutaneous injections of RG1068 at 10 µg/kg and will be divided between those receiving SSRI’s and those not receiving SSRI’s. Those not receiving SSRI treatment will further be divided between newly diagnosed, SSRI-naïve patients and patients who received SSRI’s in the past but who have discontinued treatment for at least twelve weeks prior to enrollment. If there are no drug-related serious adverse events, an additional eight patients will be enrolled and receive RG1068 at 20 µg/kg. This group will also be divided between those receiving SSRI’s and those not receiving SSRI’s. Those not receiving SSRI treatment will be further divided in the same manner as before; newly diagnosed, SSRI-naïve patients, and patients who received SSRI’s in the past but who have discontinued treatment for at least twelve weeks prior to enrollment.