A Breakthrough for Treatment-Resistant Depression
If you have tried two or more antidepressants without adequate relief, you may have treatment-resistant depression (TRD) — a condition that affects roughly one-third of the 21 million American adults diagnosed with major depressive disorder. For decades, these patients had few options beyond switching from one SSRI to another and hoping for a different result.
Ketamine treatment has changed that. Spravato (esketamine) — the first FDA-approved glutamate-based antidepressant — and ketamine-assisted therapy offer a fundamentally different mechanism of action that can produce results within hours or days rather than the 4–6 weeks required by traditional antidepressants.
Dr. Mark Agresti provides ketamine and Spravato treatment in Palm Beach County for patients with treatment-resistant depression, major depressive disorder with suicidal ideation, and PTSD. As a board-certified psychiatrist and psychotherapist, he manages the entire treatment arc — from initial evaluation through ongoing maintenance — without referrals to external ketamine clinics.
How Ketamine Works: The Glutamate Mechanism
Traditional antidepressants target serotonin and norepinephrine — neurotransmitters that account for a small fraction of the brain's chemical signaling. Ketamine and esketamine work on glutamate, the brain's most abundant excitatory neurotransmitter, by blocking NMDA receptors and triggering a cascade of downstream effects:
- Rapid synaptogenesis — ketamine promotes the growth of new synaptic connections in the prefrontal cortex, reversing the synaptic atrophy caused by chronic depression
- BDNF release — brain-derived neurotrophic factor (BDNF) surges after ketamine administration, supporting neuroplasticity and neural repair
- Anti-inflammatory effects — ketamine reduces neuroinflammation, which is increasingly recognized as a driver of treatment-resistant depression
- Default mode network modulation — ketamine disrupts the rigid, ruminative thought patterns characteristic of chronic depression by temporarily altering default mode network activity
This is why ketamine can work when SSRIs, SNRIs, tricyclics, and MAOIs have all failed — it is targeting an entirely different system in the brain.
Spravato vs. IV Ketamine: Understanding Your Options
Spravato (Esketamine)
- FDA-approved for TRD and MDD with suicidal ideation
- Nasal spray administered in a certified healthcare setting
- REMS program requires 2-hour monitoring post-dose
- May be covered by insurance with prior authorization
- Twice-weekly for 4 weeks, then weekly, then biweekly
- S-enantiomer of ketamine (more potent at NMDA receptor)
IV/IM Ketamine
- Off-label use for TRD, PTSD, anxiety, and chronic pain
- Administered intravenously or intramuscularly
- Typically 6 infusions over 2–3 weeks
- Generally not covered by insurance
- Rapid onset — often within first session
- Racemic ketamine (both S- and R-enantiomers)
Conditions Treated with Ketamine in Palm Beach County
Treatment-Resistant Depression
Failed 2+ antidepressants at adequate dose and duration
MDD with Suicidal Ideation
FDA-approved indication for Spravato — rapid reduction of suicidal thinking
PTSD
Emerging evidence for ketamine in complex and treatment-resistant PTSD
Bipolar Depression
Depressive episodes in bipolar disorder that have not responded to mood stabilizers
Severe Anxiety
Treatment-resistant generalized anxiety and social anxiety disorder
OCD
Glutamate-modulating effects may benefit treatment-resistant OCD
What to Expect During Ketamine Treatment
Comprehensive Evaluation
Dr. Agresti reviews your full psychiatric history, prior medication trials, medical conditions, and treatment goals. Same-day or next-day appointments are available for new patients in Palm Beach County.
Treatment Planning
Based on your evaluation, Dr. Agresti recommends Spravato, IV ketamine, or an alternative treatment. He explains the protocol, expected timeline, potential side effects, and insurance coverage options.
Treatment Sessions
Spravato is administered as a nasal spray in the office under direct physician supervision. You remain in the office for 2 hours of monitoring per REMS requirements. Most patients describe the experience as deeply relaxing.
Ongoing Care
Dr. Agresti provides concurrent psychotherapy and medication management alongside ketamine treatment. The combination of ketamine-driven neuroplasticity with therapy is more effective than either alone.
The Concierge Difference in Ketamine Treatment
Most ketamine clinics are staffed by anesthesiologists or nurse practitioners who administer the medication but do not provide psychiatric care. Dr. Agresti is a board-certified psychiatrist and psychotherapist who manages the entire treatment arc:
- Psychiatric evaluation and diagnosis — not just a checklist
- Direct physician supervision during every treatment session
- Concurrent psychotherapy to leverage ketamine-enhanced neuroplasticity
- Medication management for co-occurring conditions
- Direct cell access between appointments — no answering service
- No annual membership fee
Your doctor, every visit. Not a rotating cast of providers.
Ready to explore ketamine treatment? Book an evaluation within 24 hours.
Book AppointmentServing All of Palm Beach County
Dr. Agresti's Palm Beach office is conveniently located at 44 Cocoanut Row, Suite m-202, Palm Beach, FL 33480 — easily accessible from West Palm Beach, Lake Worth Beach, Boynton Beach, Delray Beach, Boca Raton, Jupiter, Palm Beach Gardens, Wellington, and Royal Palm Beach. Patients from across Palm Beach County and South Florida seek ketamine treatment with Dr. Agresti because of the combination of concierge-level access and board-certified psychiatric expertise that standalone ketamine clinics cannot provide.
For follow-up appointments and medication management, telehealth is available statewide for patients anywhere in Florida.
Frequently Asked Questions
Patients with treatment-resistant depression (failed 2+ adequate antidepressant trials), major depressive disorder with active suicidal ideation, or PTSD that has not responded to conventional therapy. Dr. Agresti evaluates your full psychiatric history, medical history, and prior medication trials to determine candidacy. Most patients who have struggled with depression for years and feel they have 'tried everything' are exactly the patients ketamine was designed for.
Spravato (esketamine) is sometimes covered with prior authorization from commercial insurance plans. Coverage requirements vary significantly by plan. Medicare Part D covers Spravato in most cases. Dr. Agresti's office can help evaluate your specific coverage and navigate the prior authorization process.
Some patients notice improvement after the very first session — often within hours. Most see meaningful, measurable response within the first 2–3 weeks of treatment. This is dramatically faster than traditional antidepressants, which typically require 4–6 weeks to reach therapeutic effect. For patients with suicidal ideation, this rapid onset can be lifesaving.
During Spravato administration, patients may experience mild dissociation (a feeling of detachment or floating), dizziness, and slight nausea. These effects typically peak within 30–40 minutes and resolve within 2 hours. The REMS monitoring protocol requires patients to remain in the office for at least 2 hours post-dose. Many patients describe the experience as deeply relaxing. You should not drive for the remainder of the day after treatment.
Traditional antidepressants (SSRIs, SNRIs) work on serotonin and norepinephrine systems and take 4–6 weeks to show effect. Ketamine and esketamine work on the glutamate system — the brain's most abundant neurotransmitter — and promote rapid synaptogenesis (new neural connections). This is a fundamentally different mechanism, which is why ketamine can work for patients who have failed multiple conventional antidepressants.
The standard Spravato protocol is twice weekly for the first 4 weeks (induction phase), then once weekly for weeks 5–8 (optimization), then once weekly or every two weeks for maintenance. Each session lasts approximately 2.5 hours including the required monitoring period. Dr. Agresti adjusts the schedule based on your individual response.
The administration of Spravato and IV/IM ketamine must occur in a certified healthcare setting under direct physician supervision — this cannot be done via telehealth. However, all follow-up appointments, medication management, and therapy sessions with Dr. Agresti can be conducted via secure telehealth for patients anywhere in Florida.
Dr. Agresti personally evaluates every patient, determines candidacy, prescribes and supervises all ketamine and Spravato treatments, and provides ongoing psychiatric care. You see the same board-certified psychiatrist at every visit — no PAs, no NPs, no referrals to a ketamine clinic. This is the concierge difference.
Ready to Take the First Step?
Appointments available within 24 hours. Direct cell access. No membership fee.