Who Is a Good Candidate for Ketamine Therapy: Assessment Criteria

You’ve tried the medications. Maybe several of them. You’ve sat through therapy sessions, journaled, exercised, cleaned up your diet, and forced yourself to socialize when every cell in your body wanted to hide. And still, the depression sits there. Or the anxiety hums in the background of every quiet moment. Or the PTSD pulls you back into a memory you’d give anything to forget.

So when you hear about ketamine therapy, with its 70% response rate for treatment-resistant depression and effects that can kick in within hours instead of weeks, the natural question follows: would it actually work for me?

That’s the right question to ask. Ketamine therapy isn’t a one-size-fits-all solution, and the honest answer is that it works wonderfully for some people and isn’t appropriate for others. This guide walks you through the assessment criteria physicians use to determine candidacy, the conditions that respond best, the medical factors that might rule someone out, and what actually happens during a candidacy evaluation at Catalyst Health & Wellness in Houston.

Why Candidacy Matters More Than You Think

Before we get into specifics, here’s something worth understanding. Ketamine therapy works on the glutamate system in the brain, which is a fundamentally different pathway than the serotonin and norepinephrine systems targeted by traditional antidepressants like SSRIs and SNRIs. That’s part of why it can help people who haven’t responded to conventional medications. But it also means the assessment process looks different.

A good candidate isn’t just someone who’s struggling. It’s someone whose specific clinical picture, medical history, and treatment goals align with what ketamine therapy can realistically deliver. Skipping that match-up step is how patients end up disappointed or, worse, exposed to unnecessary risk.

The team at Catalyst, led by Dr. Ho, a board-certified anesthesiologist with deep experience in ketamine medicine, takes candidacy seriously. The free consultation isn’t a sales pitch. It’s a real clinical conversation designed to figure out whether this treatment is right for your specific situation.

Conditions That Respond Well to Ketamine Therapy

Research over the past two decades has shown ketamine to be effective across a surprisingly broad range of conditions. The strongest evidence supports its use for treatment-resistant depression, where studies consistently show response rates between 50% and 70% in patients who haven’t improved on multiple antidepressants.

Beyond depression, ketamine has shown meaningful benefit for the following conditions:

• Anxiety disorders, PTSD, and OCD — particularly when symptoms haven’t fully responded to therapy and medication
• Bipolar depression and acute suicidal ideation — where ketamine’s rapid onset can be lifesaving when traditional treatments are too slow
• Chronic pain conditions, including fibromyalgia, migraines, and Ehlers-Danlos Syndrome — where ketamine modulates pain pathways through entirely different mechanisms than opioids or NSAIDs

If you’re dealing with one of these conditions and traditional approaches haven’t gotten you where you need to be, you’re already in the population most likely to benefit. To understand the science behind how the treatment works and what to expect, you can learn more about ketamine therapy at Catalyst Health & Wellness.

The Treatment-Resistant Depression Threshold

Most ketamine candidacy frameworks borrow heavily from the criteria used to evaluate patients for FDA-approved Spravato (esketamine), which itself was approved specifically for treatment-resistant depression. According to Mayo Clinic, patients generally need to have failed at least two antidepressant trials at adequate dosages and durations to meet criteria for esketamine treatment.

That same threshold serves as a useful starting point for IV and IM ketamine candidacy too. If you’ve been on antidepressants for at least 4 to 6 weeks at therapeutic doses without meaningful improvement, and you’ve tried this with at least two different medications, you fit the clinical profile that responds best.

But here’s where it gets nuanced. Treatment-resistant doesn’t mean “tried everything and given up.” It means your depression has demonstrated a pattern of not responding adequately to first-line approaches. That distinction matters because some patients arrive having tried only one antidepressant for a few weeks before quitting due to side effects. That isn’t true treatment resistance, and the consultation process helps clarify where you actually stand. For more detail on how this assessment unfolds, you can explore depression treatment options in Houston.

Medical Factors That Affect Candidacy

Ketamine has an excellent safety profile when administered in a controlled medical setting, but certain medical conditions require careful evaluation. The Mayo Clinic and other major medical institutions outline several factors that physicians weigh during candidacy assessments. You can review their broader guidance on esketamine and treatment-resistant depression criteria.

Conditions that may complicate or preclude ketamine therapy include uncontrolled high blood pressure, recent cardiovascular events like heart attack or stroke, certain arrhythmias, severe liver disease, active psychotic disorders, and a history of substance use disorder, particularly involving dissociative drugs. Pregnancy is also a contraindication since ketamine can cross the placental barrier.

None of these are automatic disqualifiers without context. A patient with well-controlled hypertension on medication may be perfectly fine to proceed. Someone in stable, long-term recovery from a substance use disorder may still be a candidate with appropriate clinical support. The point of the consultation is to look at the full picture rather than apply blanket rules.

The Psychological Profile That Tends to Do Well

Beyond the medical checklist, there’s a psychological dimension to candidacy that’s worth talking about. Patients who tend to do well with ketamine therapy share a few characteristics. They’ve usually exhausted the standard playbook and are looking for something different. They’re open to a treatment approach that includes some altered perception during sessions, even if that feels unfamiliar at first. And they’re willing to engage with the integration process afterward, whether that means talking through their experience with a therapist, journaling, or simply giving themselves space to process.

Ketamine isn’t a magic eraser. It’s more accurately described as a window. It opens up a period where the brain becomes more flexible, more able to form new neural connections, and often more receptive to therapeutic work. Patients who lean into that window, who use the treatment as a catalyst rather than a passive cure, generally see the best long-term outcomes.

This is also why ketamine therapy works best as part of a coordinated treatment plan rather than a standalone fix. At Catalyst, the team works alongside your existing therapist or psychiatrist whenever possible, treating the medication as one tool in a broader recovery strategy.

What Happens During a Candidacy Evaluation

If you’re considering ketamine therapy at Catalyst, the process starts with a free consultation. This isn’t a quick phone call. It’s a thorough conversation that covers your treatment history, current medications, medical conditions, mental health symptoms, and goals for treatment.

Dr. Ho or another member of the clinical team will review what’s worked, what hasn’t, and why. They’ll ask about side effects you’ve experienced with previous treatments, any patterns in your symptoms, and what specifically you’re hoping to change. Blood pressure and basic vitals get checked. If anything in your history needs further evaluation, like a cardiac issue or a complex medication regimen, that gets flagged and addressed before any treatment decision is made.

The consultation also gives you a chance to ask questions, voice concerns, and decide whether the approach feels right. There’s no pressure to commit, and the team will be straightforward if they think a different treatment, like Spravato, TMS, or Stellate Ganglion Block, might be a better fit for your situation.

When Ketamine Isn’t the Right Answer (Yet)

Sometimes the honest answer is “not right now.” That might be because you haven’t yet tried the standard treatments that insurance and clinical guidelines expect you to try first. It might be because a current medical situation needs to be stabilized before ketamine can be considered. Or it might be because another modality, like TMS for someone with cardiovascular concerns or Spravato for someone seeking insurance coverage, is a better starting point.

A good clinic will tell you that. The goal isn’t to fill chairs. It’s to match patients with the treatment most likely to actually help them.

Getting Clarity on Your Next Step

The only way to know whether you’re a candidate for ketamine therapy is to have an actual clinical conversation with someone qualified to make that assessment. Reading about it online can help you prepare, but the answers depend on your specific history, your specific symptoms, and your specific goals.

If you’ve been carrying this question around, wondering whether ketamine might finally be the thing that helps, the next step is simple. Call Catalyst Health & Wellness at 800-772-1242 to schedule a free consultation. The team operates three locations across Houston, with extended hours seven days a week, so getting in for an evaluation doesn’t require rearranging your life.

You don’t have to keep guessing. Let’s find out together.

Catalyst Health & Wellness Locations

Catalyst Health & Wellness Heights

104 W. 12th Street, Suite B, Houston, TX 77008

Phone: 800-772-1242

Hours: Monday through Sunday, 5 AM to 9 PM

Catalyst Health & Wellness Southwest

7710 Beechnut, Suite 206, Houston, TX 77074

Phone: 800-772-1242

Hours: Monday through Sunday, 5 AM to 9 PM

Catalyst Health & Wellness South Loop

6300 West Loop S, Suite 526, Bellaire, TX 77401

Phone: 800-772-1242

Hours: Monday through Sunday, 5 AM to 9 PM

Hours: Monday through Sunday, 5am to 9pm
Website: https://catalystketamine.com/

 

Medical Disclaimer

The information provided in this blog post is for educational and informational purposes only and is not intended as medical advice. It should not be used as a substitute for professional consultation, diagnosis, or treatment from a qualified healthcare provider. Ketamine therapy, Spravato treatment, TMS therapy, and Stellate Ganglion Block treatments are medical interventions that require comprehensive evaluation by a licensed medical professional to determine appropriateness for each individual patient. Individual results vary, and no specific outcome is guaranteed. Always consult with your physician or qualified healthcare provider before starting, stopping, or changing any treatment plan. If you are experiencing a mental health crisis or thoughts of self-harm, please call 988 (Suicide and Crisis Lifeline) or go to your nearest emergency room immediately.