Ketamine Assisted Therapy

Understanding the Medicine, the Experience, and What Happens Afterward

At a party recently, a new friend asked me what I was excited about in my work. My eyes lit up as I started telling her about Ketamine-Assisted Psychotherapy (KAP). She was intrigued. She'd heard about ketamine from friends and through stories in the news, but she was also understandably confused. Isn't ketamine an anesthetic? A party drug? How did it end up being used in mental health treatment? What does the experience actually feel like? And what does therapy have to do with it?

We ended up talking for quite a while.

These are questions I hear often, and they're good ones. Ketamine is an unusual medicine with a long history in anesthesia and a much newer - and still evolving - role in mental health treatment. There's promising research, plenty we still don't know, and, increasingly, a lot of hype.

So I thought I'd share some of what I told her, along with what I've learned since I began incorporating KAP into my work.

What is Ketamine?

Ketamine isn't new. It was first synthesized in 1962 and approved by the FDA as an anesthetic in 1970. It continues to be widely used in medicine, including in anesthesia and emergency care. Its use in mental health treatment came later. Research has found that ketamine can produce rapid antidepressant effects, including for some people whose depression has not responded to conventional treatments. In 2019, the FDA approved esketamine (Spravato), a nasal-spray medication derived from ketamine, for treatment-resistant depression. Ketamine itself is used off-label in mental health treatment.

Ketamine is classified as a dissociative anesthetic, and at the lower doses typically used in mental health treatment it can also produce psychedelic and empathogenic effects. People may experience changes in perception, a sense of distance from their usual thoughts or identity, imagery or visual phenomena, emotional openness, increased connection, or a different relationship to their body.

In my practice, ketamine is used within a therapeutic process that includes preparation, the medicine session itself, and integration afterward. This approach is commonly called Ketamine-Assisted Psychotherapy (KAP), or sometimes Ketamine-Assisted Therapy (KAT).

What is Ketamine used for?

The strongest psychiatric evidence for ketamine is for depression, particularly treatment-resistant depression, where its rapid antidepressant effects have been studied extensively. Ketamine and ketamine-assisted approaches are also being investigated for other concerns, including PTSD, anxiety, substance-use disorders, and suicidality, although the strength of the evidence varies considerably by condition.

It's important to distinguish the evidence for ketamine as a medication from the research on ketamine combined with therapy. There is growing research on the combination, with promising findings in some areas, but we don't yet have strong evidence establishing exactly what therapy adds, which therapeutic approaches are most helpful, or for whom.

The unanswered research questions are important, and so is the complexity of psychotherapy itself. Who is sitting with you matters. So does the relationship you've developed, how you prepare together, how you're supported during the medicine experience, and what happens afterward. Therapy isn't a single ingredient that can easily be separated from all of those things. They're difficult variables to isolate in research, and they're central to how I practice KAP.

What does ketamine do in the brain?

Ketamine primarily acts on the brain’s glutamate system, where it blocks a type of glutamate receptor called the NMDA receptor. This sets off a cascade of downstream effects involving another type of glutamate receptor, the AMPA receptor, as well as brain-derived neurotrophic factor (BDNF) and other signaling pathways involved in synaptic plasticity. Researchers are still working to understand exactly which of these mechanisms are responsible for ketamine’s rapid and sustained antidepressant effects.

One of the things I find especially fascinating is ketamine’s relationship to neuroplasticity - the nervous system’s capacity to change and reorganize in response to experience. In preclinical studies, ketamine has been shown to promote synaptogenesis (the formation of new connections between neurons) and the formation and restoration of dendritic spines, the tiny structures on neurons where many of those connections occur. Some studies have found that ketamine can reverse stress-related losses in dendritic spines and synaptic functioning. Much of the research allowing scientists to actually observe these structural changes has been done in animals, so we need to be careful about assuming that the same process occurs in precisely the same way in the human brain.

Ketamine may create a period of increased neuroplasticity, giving the nervous system greater capacity for new learning. What happens during that period isn't determined by the medicine alone - our nervous systems are continually shaped through experience, so what we pay attention to, what we experience in our bodies and relationships, and what we begin to do differently can help shape what is learned. This is one reason I place so much emphasis on preparation and integration in KAP.

What does a ketamine session feel like?

Ketamine experiences vary considerably - not only from person to person, but from one session to the next. Some people feel deeply relaxed or experience a sense of distance from their body, thoughts, or usual concerns. Perception may shift: time and space can feel different, imagery or visual phenomena may arise, and some people describe a sense of expansiveness, connection, or access to emotions and perspectives that feel less available in their ordinary state.

Others may encounter sadness, fear, discomfort, confusion, or something they weren't expecting. And sometimes, a person may not feel that much at all. A medicine session doesn't need to feel profound for something useful to come from it. For me, what happens afterward can be just as important as - and sometimes even more important than - the medicine experience itself.

During the medicine session, I generally encourage an inward journey, using eyeshades and music to support attention to the experience as it unfolds. I'm there with the client throughout, paying attention to what I'm observing and available when interaction or support is needed. Rather than trying to talk through or immediately make sense of everything, I encourage clients to notice what emerges - the sensations, emotions, images, thoughts, memories, or whatever else arises - and allow the experience to unfold.

How many KAP sessions are recommended?

A series of 6–8 medicine sessions is a common initial KAP protocol, and it's the framework I was trained in. However, the number of sessions can vary. Some people may benefit from fewer sessions, while others may continue beyond the initial series or return for occasional maintenance sessions.

In my practice, I don't assume that everyone needs the same number. We pay attention to how you're responding, what we're working on, and whether continuing with the medicine sessions feels clinically useful. Preparation and integration are also important parts of the process, so I think of KAP as more than simply completing a prescribed number of ketamine sessions.

Is ketamine safe? What about addiction?

Ketamine has a long history of use in medicine, but that doesn't mean it's appropriate or risk-free for everyone. Before beginning KAP, clients are medically screened to determine whether ketamine is appropriate for them. Because ketamine can temporarily increase blood pressure and heart rate, certain cardiovascular conditions may require additional consideration or make treatment inappropriate.

Ketamine also has the potential for misuse and dependence, particularly when it is used frequently or outside of a medically supervised setting. At the same time, current research suggests that the risk of misuse is relatively low when ketamine is prescribed and used within a structured, monitored clinical setting. A history of substance use doesn't automatically tell us whether someone is or isn't appropriate for treatment, but it is an important part of the assessment and ongoing monitoring.

In my practice, I provide the therapy component of KAP and collaborate with a medical provider who handles medical screening, prescribing, and monitoring.

What are the possible side effects?

Temporary side effects can include increases in blood pressure and heart rate, dizziness, nausea, headache, sedation, changes in coordination, dissociation, and sometimes anxiety or confusion. These vary from person to person and generally resolve as the acute effects of the medicine wear off.

In my current KAP model, ketamine is taken sublingually, swished, and then spit out rather than swallowed. This allows much of the medicine to be absorbed through the oral mucosa while limiting the amount that enters the gastrointestinal tract and undergoes first-pass metabolism. I find this approach tends to reduce nausea and other physical side effects for my clients, although individual responses vary.

What about longer-term risks? 

Long-term or frequent ketamine exposure can also affect the urinary tract and bladder. These problems are most strongly associated with heavy recreational use, but that doesn't mean they are irrelevant in medical treatment. Emerging research suggests that greater dose, frequency, and duration of exposure may increase risk, and we still need better long-term data on repeated psychiatric use.

Why am I so excited about Ketamine-Assisted Psychotherapy?

Some of my excitement about KAP comes from moments I've had the privilege of witnessing with clients. I've sat with someone as they experienced what it felt like to love themselves for the first time. More recently, a client described feeling peace inside - and realizing, through the contrast, just how much anxiety and stress they had been carrying without fully recognizing it.

I've also watched clients find greater distance from anger or anxiety that had felt overwhelming, make significant changes in their relationship with substances, and begin relating differently to people they love. These are individual experiences, and I don't assume that ketamine alone created the changes that followed. But witnessing them has deepened my curiosity about what can become possible when familiar patterns become less rigid and someone has access, even temporarily, to a different experience of themselves.

Sometimes the shift happens during the medicine session itself. Other times it's quieter and becomes apparent afterward. Someone may notice more space around a harsh inner critic, respond differently to something that would ordinarily trigger an automatic reaction, or discover that they have access to greater compassion, openness, or choice.

This is where the combination of ketamine and therapy becomes especially interesting to me. When familiar patterns become less rigid and something different arises, that gives us something to work with.

This is also why preparation and integration are such important parts of how I practice KAP. Before a medicine session, we spend time exploring what you're bringing into the experience and what you want to work with. Afterward, we pay attention to what emerged and how it connects with your life - and we work actively with it. That might mean practicing a different response to a familiar trigger, experimenting with a new behavior, setting a boundary, approaching a relationship differently, or strengthening a way of relating to yourself that became more accessible during the experience.

For me, the medicine session is one part of the process. Integration is also about intentionally harnessing the period of increased neuroplasticity that follows. Together, we identify what you want to work on and translate that into simple, actionable steps you can take in your everyday life, creating opportunities for new experiences, responses, and ways of relating.

If you're curious about whether KAP might be appropriate for you or have questions about how I work, or are looking for support in person in Sonoma County or online in California, you're welcome to contact me.

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Sources:

• Veraart et al. (2026), Clinical Psychology Review — systematic review of ketamine-assisted psychotherapies. This is probably the most important source for your discussion of KAP itself: 72 studies, only 11 RCTs, substantial heterogeneity, and insufficient evidence yet to establish the added contribution of psychotherapy.

  
  

  PubMed: Ketamine-assisted psychotherapies for mental disorders

• Liao et al. (2025), Nature Reviews Neuroscience — structural neural plasticity. Excellent support for your careful discussion of dendritic spines and the distinction between strong preclinical evidence and what we can infer in humans.

  
  

  Structural neural plasticity evoked by rapid-acting antidepressant interventions

• Simpson & Juruena (2026), Psychopharmacology — KAP for treatment-resistant depression. Useful current systematic review showing promising outcomes while emphasizing heterogeneity and the lack of demonstrated superiority in the controlled studies.

  
  

  PubMed: Effectiveness of KAP for treatment-resistant depression

• Kerr-Gaffney et al. (2025), Journal of Psychopharmacology — urinary symptoms. This is much better than the older general-public bladder source. It specifically examines ketamine used for psychiatric treatment and makes clear both what has and hasn't been demonstrated about urinary risk.

  
  

  PubMed: Urological symptoms following ketamine treatment for psychiatric disorders

• Andrade (2025), Journal of Clinical Psychiatry — ketamine-associated uropathy. Particularly useful for your point that therapeutic prescribing isn't automatically risk-free: higher doses, greater frequency and longer duration are identified as potential risk factors in maintenance treatment.

  
  

  PubMed: Ketamine-associated uropathy during therapeutic and nontherapeutic use

• 2025 systematic review on ketamine's potential entactogenic effects. This gives you contemporary support for retaining the empathogenic/entactogenic aspect rather than deleting it during our evidence cleanup. It remains appropriately qualified—the review found potential entactogenic effects, while effects on human empathy/prosocial behavior remain uncertain.

  
  

  PubMed: Can ketamine and other glutamate receptor modulators be considered entactogens?