Overview:
Our program offers an intravenous ketamine intervention for individuals with treatment resistant depression. Ketamine is an N-methyl-D-aspartate receptor antagonist, which has long been used as an anesthetic medication. Recent evidence shows that subanesthetic doses of ketamine have rapid and robust antidepressant and anti-suicidal effects, which can have potentially life-saving relief for many individuals. Ketamine appears to work by mediating the glutamatergic system, which leads to changes in neural signaling and connectivity in relation to emotion and cognition in the brain. These changes in brain pathways result in improved depressive symptoms.
Eligibility:
Treatment Protocol:
The treatment protocol will include two treatments with intravenous ketamine each week for three weeks using a sub-anesthetic dose of ketamine.
Overview:
The stellate ganglion is a part of the cervical sympathetic chain, and it provides sympathetic input to the ipsilateral upper extremity, chest, head, and neck. Using ultrasound guidance, an anesthetic block of the stellate ganglion can affect changes to neural processes which are known to be implicated in depression. Currently, an antidepressant-like effect has been demonstrated in animal models using a stellate ganglion block. This program aims to investigate whether this effect can be replicated in humans.
Eligibility:
Intervention Protocol:
This is a pilot study investigating a Stellate Ganglion Block, a new intervention for major depressive disorders. The first step of the procedure involves the infusion of a sedative agent (midazolam) to induce sleep if necessary. The second step will involve the injection of Lidocaine (a local anaesthetic) into the neck to reduce pain in the region.
The third step will involve the injection of an investigational anaesthetic medication called SENSORCAINE® (5 mg/mL) using ultrasound guidance.
This procedure will take less than 30 minutes, plus 60 minutes of recovery time.
Overview:
Nitrous oxide is an anesthetic gas that is frequently encountered in dental offices, although it is also used in a variety of settings including labor and delivery units and operating rooms. It is inexpensive and is on the World Health Organization’s list of essential drugs. Nitrous oxide is believed to work as an NMDA receptor antagonist, a mechanism shared with ketamine. However, unlike ketamine, it has minimal side effects. Current evidence has demonstrated that a single administration of nitrous oxide has been shown to decrease depressive symptoms, and there is ongoing research examining the effects of nitrous oxide in depression. Thus, we intend to carry out a research study to explore the clinical efficacy and functional outcomes of repeated nitrous oxide administrations.
Eligibility:
Treatment Protocol:
This is a pilot study that will utilize repeated administrations of nitrous oxide gas using a randomized approach.
Participants will be randomized to receive either inhaled nitrous oxide gas plus infused saline solution, or placebo (inhaled oxygen gas with infused midazolam–a different sedative agent)
Participants will be given 50% mg/mL of nitrous oxide to inhale plus a saline solution delivered intravenously, or 50% oxygen gas to inhale plus 1 mg/mL of midazolam delivered intravenously. Both interventions will last one hour, and will be administered once a week for four weeks.
Participants will be followed for 90 days after completion of treatment.
