What Does Ketamine Do to Your Brain
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Ketamine is a drug that doctors use as an anaesthetic in hospitals, in carefully controlled settings, where trained staff watch the patient closely and the setting is chosen for safety. Outside a hospital, the same drug is sometimes used on its own, without any of that care, and that is where the danger to the brain begins. Ketamine belongs to a group of drugs called dissociatives, which means it changes how the brain connects what you see, hear and feel with what is really happening around you. People who take it often describe feeling cut off from their own body, as if they are watching themselves from a distance, or as if the room around them has become strange and unreal. That feeling may sound harmless, even interesting, to someone who has never felt it. In reality it is a sign that the brain is not working normally, and that its normal way of keeping you safe has been switched off for a while.
The brain is a careful organ. Every second it takes in signals from your eyes, your ears, your skin and your body, and it turns those signals into a clear picture of where you are and what you should do next. It also holds your memories, your plans and your sense of who you are, and it uses all of that to help you make sensible choices. Ketamine interferes with that work. It blocks some of the signals that brain cells use to talk to each other, especially signals carried by a chemical messenger called glutamate. When those signals are blocked, the brain cannot put the picture together properly. Thoughts become loose and hard to follow. Time seems to stretch or shrink. Simple things, like standing up, walking across a room or answering a question, become confusing. A person may feel calm, or frightened, or completely lost, and they may not be able to tell which of those feelings matches the real situation.
This article explains, in plain words, what ketamine does to the brain: what happens in the hours after it is taken, how memory and thinking change with repeated use, why judgement becomes weaker, and what can improve when use stops. It is general information, not individual medical advice. It does not tell anyone how to use ketamine, and it does not suggest any dose or method. If you are worried about your own health, or about someone you care about, a qualified health professional is the right person to talk to.
What Ketamine Does When It Reaches the Brain
When ketamine enters the body, it travels in the blood to the brain, and its effects begin quickly. The first thing most people notice is a change in how the world feels. Sounds may seem louder or further away. Colours may look brighter or stranger. The body may feel light, heavy, numb or hard to move. Some people feel as if their arms and legs belong to someone else. Others feel as if they are floating, or sinking, or stuck in one place while the room moves around them. These are not small changes. They are the brain losing its normal grip on the senses, and for the time the drug is active, the person cannot trust what their senses are telling them.
Inside the brain, ketamine blocks receptors that normally receive glutamate, one of the main chemical messengers that brain cells use to send information. Glutamate helps the brain learn, remember and pay attention. When its signals are blocked, messages between brain cells slow down or go missing. That is why a person on ketamine may struggle to follow a conversation, remember what was said a minute ago, or understand a simple instruction. It is also why they may react slowly to danger. A hot surface, a busy road, a flight of stairs or a person offering help can all be misunderstood in that state, and the person may not realise they are at risk until it is too late. The brain’s warning system is still there, but the drug has muffled it.
The feeling of being cut off from reality has a name in medicine: dissociation. In a hospital, doctors use a measured amount of ketamine to create a short, controlled form of dissociation so that a patient does not feel pain during a procedure, and trained staff are there to keep the patient safe. Outside a hospital, there is no control, no monitoring and no one to step in if something goes wrong. The same feeling that is useful for a few minutes in an operating theatre becomes dangerous in a bedroom, a car or a crowded party, because the person cannot judge risk, cannot move properly and cannot ask for help clearly. What makes it worse is that the person may not remember the experience clearly afterwards. The brain, while the drug is active, does not lay down memories in the normal way, so hours can pass in a blur, and the person may wake up unsure what happened, where they went, or who they were with.
Why Thinking Feels Detached and Unreal
The strange, floating feeling that ketamine causes comes from the way it changes the brain’s sense of self. Normally, your brain keeps a steady sense of where your body ends and the world begins. You know your hand is yours. You know the floor is under your feet. You know the voice you hear is your own thought, not someone else speaking. Ketamine weakens those boundaries. A person may feel as if they are outside their own body, looking down at themselves. They may feel as if the room is not real, or as if they have slipped into a dream while still awake. Some people find this frightening. Others find it calm or fascinating, and that calm feeling is part of the danger, because it makes a harmful experience feel harmless.
Thinking itself becomes harder while the drug is active. The brain normally holds several thoughts at once: what you are doing now, what you need to do next, what happened a moment ago. Under ketamine, that holding power breaks down. A thought starts and then drifts away before it is finished. A question is asked and the answer never arrives, because the thread of the conversation has been lost. Numbers become hard to add. Names become hard to recall. A person may repeat the same sentence, or stare at a simple object as if they have never seen it before. None of this is a sign of a strong mind exploring new ideas. It is a sign of a brain that cannot do its basic work, and the confusion can last for hours after the main effects have faded.
For some people, the experience turns frightening. The sense of being cut off can become panic. The room may seem to close in, or stretch endlessly. Familiar faces may look strange. A person may feel certain that something terrible is about to happen, without knowing what it is, and they may not be able to explain that fear to anyone nearby. This kind of frightening experience can stay in the memory long after the drug has worn off, and it can leave a person anxious about being alone, about sleeping, or about being in crowded places. The brain does not simply forget a bad experience because the drug is gone. It remembers the fear, and that memory can shape how a person feels for weeks afterwards.
Memory, Learning and Everyday Focus
Memory is one of the parts of the brain most affected by ketamine, and the damage shows up in ordinary life in ways that are easy to miss at first. A person who uses ketamine often may start forgetting small things: where they put their keys, what they were told at work, what they promised a friend, what they read in a book the day before. These are not the forgetful moments everyone has from time to time. They happen more often, and they get worse with more frequent use. The reason is simple. The brain forms new memories by strengthening the links between brain cells, and glutamate is central to that process. When ketamine blocks glutamate again and again, those links do not form properly, and new information slips away before it is stored.
Learning suffers in the same way. A student who uses ketamine may find that studying takes twice as long and the work still does not stay in their mind. A worker may find that a new task, learned one day, has to be learned again the next. Instructions that used to be easy to follow become a muddle. This is not a lack of effort or intelligence. It is a brain that cannot hold new information long enough to keep it. Over months, that gap grows. The person falls behind at school or at work, not because they stopped trying, but because the tool they need for learning, their memory, is no longer working as it should. That loss can be hard to accept, and it can make a person feel stupid or lazy, when the real cause is the drug.
Focus is affected too, and it stays affected longer than most people expect. After the drug wears off, thinking can feel cloudy for a day or more. The person may sit down to read and find their eyes moving over the same paragraph again and again. They may start a task and lose track of it halfway through. They may struggle to listen to a friend, because their attention keeps drifting. Public health guidance and research on heavy, repeated use link these problems with longer-lasting changes: people who use ketamine often over a long period tend to perform worse on tests of memory, attention and planning than people who do not use it, and the difference is larger in those who use it most often. The good news, which this article returns to later, is that some of this can improve when use stops. The warning is that improvement is slow, and it is not guaranteed to be complete.
Judgement, Decisions and Risk
Good judgement depends on the brain being able to weigh what might happen next. Before you cross a road, your brain checks the traffic. Before you spend money, it checks what you need it for. Before you trust a stranger, it checks what you know about them. Ketamine weakens that checking process. While the drug is active, a person may agree to things they would never agree to normally, or take risks they would normally avoid, because the part of the brain that pauses and thinks ahead is not working properly. That is one of the reasons ketamine is linked with accidents, injuries and situations where a person is taken advantage of. The person is not careless by nature. Their brain, for a few hours, cannot do the careful work it normally does.
The problem does not end when the drug wears off. People who use ketamine often may find that their everyday judgement becomes weaker over time. They may make hasty decisions about money, about relationships, about work, or about their health. They may find it harder to stick to a plan, or to say no when they want to. This happens because the front part of the brain, the part that helps with planning, self-control and thinking about consequences, is sensitive to repeated disruption. When that part is weakened, the person lives more in the moment and less in the future. Short-term feelings matter more than long-term plans, and that shift can quietly damage a life: savings are spent, courses are dropped, friendships are strained, and the person may not see the pattern until a lot has already been lost.
There is another risk that deserves to be said plainly. Because ketamine can leave a person confused, unsteady and unable to move or speak clearly, they are less able to protect themselves. They may fall, hit their head, or wander into danger. They may be unable to call for help, or to explain what is wrong if help arrives. In a group, others may not realise how much trouble the person is in, because the person may seem calm or asleep when they are actually in serious difficulty. Breathing can also be affected, especially when ketamine is taken alongside alcohol or other drugs that slow the body down, and that combination is one of the most dangerous things about it. A person who seems to be sleeping it off may in fact need urgent medical help, and the people around them may not know. That is why anyone who finds a person unresponsive or struggling to breathe after taking any drug should seek emergency help straight away, rather than waiting to see if they wake up.
Mood, Sleep and the Days After
Ketamine does not only change thinking while it is active. It changes mood in the days that follow, and those changes can be hard to live with. Some people feel low, flat or empty for a day or two after use. Others feel anxious, restless or on edge, as if something is wrong but they cannot say what. Sleep is often disturbed. A person may find it hard to fall asleep, or may wake in the night with strange dreams, or may sleep for a long time and still wake up tired. The brain needs sleep to sort out memories and to recover from the day, and when sleep is broken, thinking the next day is worse, which makes the whole cycle harder to break.
With repeated use, the mood changes can become more settled and more serious. A person may lose interest in things they used to enjoy: music, food, friends, sport, work. They may feel cut off from the people around them, even when those people are trying to help. They may feel that nothing matters very much, or that life has become grey and dull. This is not simply a bad mood. It is a brain whose reward system, the part that makes ordinary pleasures feel rewarding, has been disturbed again and again by a drug that floods it and then leaves it empty. When ordinary life stops feeling rewarding, the drug can start to feel like the only thing that brings any relief, and that is how a habit becomes a trap. The person uses ketamine to escape the flat feeling, and the flat feeling gets worse because of the ketamine, so they use it again. Breaking that circle is difficult, and it usually needs support from other people, not willpower alone.
It is worth saying clearly that ketamine is also used in medicine in a very different way, in small, controlled amounts, for some people with severe depression that has not improved with other treatments, and that treatment is given by specialists in a clinic, with careful screening and monitoring. That medical use is not the same as taking ketamine on your own, and it does not make unsupervised use safe. The fact that a drug can help some patients in a hospital does not mean it is harmless at a party, in a bedroom, or taken again and again without medical care. The setting, the amount and the supervision change everything, and without them, the risks to mood and thinking are real.
Repeated Use and the Slow Changes
The most worrying changes from ketamine are not the ones that happen in a single evening. They are the ones that build up slowly, over weeks and months, so quietly that the person does not notice them until they are already serious. Thinking becomes slower. Words become harder to find. Plans become harder to make and harder to keep. A person who once managed a busy day without trouble may start to feel overwhelmed by ordinary tasks: cooking a meal, paying a bill, catching a bus, answering an email. Each task on its own is small, but together they add up to a life that feels harder to manage, and the person may blame themselves, or blame stress, or blame getting older, when the drug is part of the cause.
Research on people who use ketamine heavily over a long time has found lasting problems with memory and with the kind of thinking that involves planning and solving problems. Some of these problems improve after a person stops using ketamine, but the recovery can take months, and studies suggest that people who used it very heavily for a long time may not return fully to how they were before. That is a serious warning, and it should be taken seriously by anyone who thinks that ketamine is a harmless drug because its effects wear off in a few hours. The hours pass, but the brain keeps a record of what was done to it, and that record is written in slower thinking, weaker memory and poorer judgement.
There is also a well-known harm that sits outside the brain but affects the whole person: damage to the bladder. People who use ketamine often may develop pain when passing urine, a need to pass urine very often, and in severe cases lasting damage to the bladder that needs medical care. This happens because ketamine and the substances the body makes from it irritate the bladder lining. It is a painful, frightening problem, and it is a sign that the body is being harmed, not just the mind. A person who notices these symptoms should talk to a doctor, because the damage can get worse if use continues, and because a doctor can explain what help is available. It is also a reminder that ketamine is not a drug that affects only one part of the body. It affects the brain, the bladder, the mood and the whole of daily life.
What Improves When Use Stops
Stopping ketamine is not easy, and this article will not pretend otherwise. A person who has used it often may feel flat, anxious and restless for a while after stopping, and they may find it hard to sleep or to concentrate. They may miss the feeling the drug gave them, even while they know it was harming them. Those feelings are normal, and they are a sign that the brain is adjusting, not a sign that stopping was a mistake. The brain has spent months or years adapting to the drug, and it needs time to learn how to work without it again. That time is measured in weeks and months, not days, and patience matters more than speed.
The improvements, when they come, are real. Thinking usually becomes clearer first in small ways: a conversation is easier to follow, a book is easier to read, a task at work is finished without losing track of it. Memory improves more slowly, and it may never feel perfect, but most people who stop find that they remember more, plan better and feel more like themselves over time. Sleep often settles, mood often lifts, and ordinary pleasures, a meal, a walk, a laugh with a friend, start to feel rewarding again. These are not dramatic changes. They are quiet ones, and they are easy to miss if you are waiting for a single moment when everything feels fixed. The truth is more gradual: the brain heals slowly, and the healing is worth waiting for.
Support makes a large difference. A person trying to stop does not need to do it alone, and doing it alone is the hardest way. A doctor can talk through what help is available, and in many countries there are drug support services that offer advice, counselling and practical help without judgement. Friends and family can help too, by being patient, by listening, and by not treating a slip as a failure. Most people who stop using a drug have difficult days along the way, and a difficult day does not erase the progress that came before it. What matters is having a plan for the hard moments, and having people to turn to when they arrive.
The Myths People Believe About Ketamine and the Brain
One common myth is that ketamine is safe because doctors use it. This confuses two very different things. In a hospital, ketamine is given in a measured amount, for a short time, to a patient who has been checked first, by staff who watch breathing, heart rate and oxygen levels, and who can act at once if something goes wrong. Outside a hospital, none of that is true. The amount is unknown, the setting is uncontrolled, the person may have taken other substances as well, and there may be no one nearby who knows what to do if breathing slows or the person becomes unresponsive. A drug that is safe in one setting can be dangerous in another, and that difference matters more than the name on the packet.
Another myth is that ketamine only affects you for a few hours, so it cannot cause lasting harm. The hours are only the visible part. The brain changes that build up with repeated use, the weaker memory, the slower thinking, the poorer judgement, do not end when the drug wears off. They linger, and they shape the days and weeks that follow. A person may feel normal the morning after, and still be carrying the effects in the way they think, learn and decide. The fact that a harm is quiet does not mean it is not real.
A third myth is that ketamine is not addictive, so there is nothing to worry about. Ketamine can lead to a pattern of use that is hard to stop, even if it does not cause the same kind of physical withdrawal as some other drugs. People can come to depend on it to relax, to escape, to feel something, or to feel nothing, and they can find that they need it more often to get the same feeling, while the harms keep growing. Dependence is not only about the body shaking or sweating when a drug is stopped. It is also about the mind coming to rely on a drug to cope with ordinary life, and that reliance is real, and it is hard to break. Anyone who feels they are losing control over their ketamine use should talk to a health professional or a drug support service, and should know that asking for help is a sensible step, not a sign of weakness.
My Take:
I will be honest with you. What worries me most about ketamine is how quietly it changes the way a person thinks, and how easily that change is missed. A broken arm is obvious. A damaged liver shows up in tests. A brain that is thinking a little more slowly, remembering a little less clearly, and judging a little less carefully does not announce itself. The person just feels a bit more tired, a bit more forgetful, a bit less able to cope, and they blame work, or age, or a bad week, when the drug is part of the reason. That quiet damage is what makes ketamine dangerous, because by the time it is obvious, months of harm have already happened, and the person has already lost ground at work, at school, or at home that is hard to win back.
I think the feeling ketamine gives is the heart of the problem. It makes a person feel cut off from their worries, cut off from their body, cut off from the world, and for a few hours that can feel like peace. But it is not peace. It is the brain being switched off, and the worries are still there when the drug wears off, usually worse than before, because nothing has been solved and the brain is now more tired and more confused. I have no patience for the idea that this is a harmless escape. An escape that damages the very organ you need to solve your problems is not an escape at all. It is a loan with a terrible rate of interest, and the brain pays it back in memory, in focus and in judgement.
What stays with me is the memory problem, because memory is not a small thing. Memory is how you know who you are, who you love, what you promised, and what you have learned. When ketamine weakens memory, it does not just make a person forget a shopping list. It makes them forget the thread of a conversation with a friend, the lesson they studied the night before, the appointment that mattered, the birthday that mattered. Each forgotten thing on its own is small, but together they add up to a life that feels thinner and less connected. A person who cannot remember properly cannot learn properly, cannot plan properly, and cannot keep the promises that hold a life together. That, to me, is a heavy price for a few hours of feeling distant from the world.
I also think about judgement, because judgement is what keeps a person safe. The brain’s ability to pause, to weigh risk, to think about what happens next, is not a luxury. It is what stops you crossing a road without looking, spending money you do not have, or trusting someone you should not trust. Ketamine weakens that pause, and it does so at exactly the moment when the person is least able to notice it, because the drug also weakens their ability to judge their own judgement. That is a frightening combination. A person who is thinking badly and cannot tell that they are thinking badly is in real danger, and no one around them may realise it, because the person may seem calm, or quiet, or simply asleep. I would rather people understood that clearly than discovered it after an accident.
The mood changes matter to me too, because they are the part that makes stopping so hard. When ordinary life stops feeling rewarding, when food, music, friends and work all feel grey, the drug starts to look like the only colour left. That is a cruel trick, because the drug is part of the reason life has gone grey, and taking more of it only makes the grey deeper. Breaking that circle needs more than a lecture about willpower. It needs time, patience, and people who will stay close while the brain slowly learns to feel pleasure in ordinary things again. If you know someone in that circle, I would ask you to be patient with them. They are not lazy or selfish. Their brain is struggling to find its way back, and that struggle is real.
I am also struck by how young many of the people affected are. A young brain is still learning how to think, how to plan, how to remember and how to judge, and ketamine interferes with all of that at exactly the age when those skills matter most. A student who loses a year to foggy thinking does not get that year back easily. A young worker who falls behind does not catch up by trying harder, because trying harder is not the problem. The problem is a brain that cannot hold what it is taught. I think that is a tragedy, and I think it deserves to be said plainly, without softening it. Young people deserve to know that this drug can take away the very abilities they need to build a life, and that the loss is not always temporary.
If someone asked me what to do, I would start with honesty. Do not pretend the drug is harmless. Do not pretend the effects end when the drug wears off. Do not pretend that a medical use in a hospital makes unsupervised use safe. Tell the truth, plainly, to yourself and to the people you care about, and then get help. Talk to a doctor. Talk to a drug support service. Tell a friend or a family member what is happening, even if that conversation feels hard. The hardest step is the first honest conversation, and after that step, the path is still long, but it is no longer walked alone. I have seen, in the stories health services tell, that people do recover, and that thinking, memory and mood do improve when use stops. It takes months, and it takes support, but it happens, and that is worth holding on to.
I would also say this to anyone who has never taken ketamine: do not start. There is nothing in those few hours of feeling distant that is worth the risk to your memory, your judgement and your mood. The feeling is not freedom. It is the brain being unable to do its work, and the bill for that arrives slowly, in forgotten names, in failed exams, in hasty decisions, in days that feel grey and empty. Walk away from the first offer, and you will never have to find your way back from the fog. That is the simplest advice in this article, and I believe it is also the most valuable.
Finally, I want to say something about blame, because blame helps no one. People who use ketamine are not foolish, and they are not bad people. Many of them started because they were curious, or because they were struggling, or because everyone around them seemed to be doing it, and by the time they understood the harm, they were already caught in the pattern. Blaming them does not help them stop. Listening to them, supporting them, and giving them honest information does. If you are reading this because you are worried about yourself, I would ask you to be kind to yourself, and to take one practical step today: talk to a health professional, or to a drug support service, or to someone you trust. You do not need to fix everything at once. You need to start, and starting with an honest conversation is enough for today. The brain can heal, slowly, and the life you want is still there on the other side of the fog.
I think about the families too, because they carry a lot of this harm in silence. A parent who watches a child become more forgetful, more distant, more careless with money, may not know what is happening, and may blame themselves, or blame the child, when neither is the real cause. A partner who watches someone they love lose interest in everything may feel helpless, and may not know what to say. If that is you, I would say that noticing is already a good step, and that talking to a health professional about what you have seen is a sensible thing to do, not a betrayal. Families do not need to solve this alone, and there are services that can help both the person using the drug and the people around them. Asking for that help is not giving up on someone. It is refusing to give up on them.
One more thing I want to be clear about is that recovery is not a straight line. There will be good days and bad days, clear days and foggy days, and a bad day does not mean the recovery has failed. The brain heals in small steps, and some weeks will feel slower than others. That is normal, and it is not a reason to stop trying. What matters is the direction over months, not the feeling on a single morning. If you are trying to stop, keep a note of the small improvements, the conversation you followed, the task you finished, the night you slept well, because those small things are the evidence that your brain is coming back, and on a hard day, that evidence matters more than any promise.
I also think about the cost of ketamine in ordinary terms, because that cost is real even when no one talks about it. The money spent on the drug is money that does not go to rent, to food, to a course, to a gift for a child, or to a saving for the future. Over months, that money adds up to a large sum, and the person who has spent it often cannot say what it bought them, because the feeling it bought lasted only a few hours and left them more tired afterwards. The time is a cost too. Hours lost to the drug, hours lost to the fog the next day, hours lost to sleep that does not refresh, are hours that could have been spent learning, working, resting properly, or being with people who matter. When I add up the money and the time, I see a drug that takes a great deal and gives very little back, and I think that is worth saying plainly, because it is a practical reason to stop, alongside all the health reasons.
There is another point I do not want to leave out, and that is how ketamine affects trust. When a person becomes more forgetful, more careless with promises, and more likely to make hasty decisions, the people around them notice, even if they do not know the cause. A friend who is let down again and again stops relying on that person. An employer who sees work slipping stops trusting them with important tasks. A family member who hears promises that are not kept stops believing the next promise. That loss of trust is painful, and it can last longer than the drug effects themselves, because trust is rebuilt slowly, through small kept promises over a long time. The good news is that it can be rebuilt. Each appointment kept, each task finished, each honest conversation is a small step back towards trust, and over months those steps add up. I would ask anyone trying to stop to remember that, and to be patient with the people around them while they learn to trust again.
I would also ask people who have never taken ketamine to think about what they would say if a friend offered it to them. It is easy to say yes in the moment, when everyone else seems to be doing it and the offer feels friendly, and it is much harder to say no. But saying no is not rude, and it is not a sign that you are afraid or boring. It is a sign that you value your memory, your judgement and your future more than a few hours of feeling distant from the world. If you are the friend who is asked, and you say no, you may also be giving the person next to you the courage to say no too. That is a small act, and it matters more than it looks.
Frequently Asked Questions
Does Ketamine damage the brain permanently?
Repeated heavy use is linked with lasting problems with memory, attention and planning, and research suggests that people who used ketamine very heavily for a long time may not fully return to how they were before, even after stopping. Lighter or less frequent use carries a lower risk, but there is no safe amount that guarantees no harm. The brain can improve a great deal after use stops, often over months, but the safest choice is not to start, and the best step for someone who is using it often is to stop and to seek support from a health professional.
How long do Ketamine brain effects last?
The strongest effects, the feeling of being cut off from reality, confusion and difficulty moving, usually last a few hours, but cloudy thinking, poor concentration and low mood can last for a day or more after use. With repeated use, the effects on memory and thinking can last for weeks or months, and they may improve only slowly after stopping. How long they last depends on how often and how heavily the drug was used, and on the person, so there is no single timetable that fits everyone.
Does Ketamine change judgement and decisions?
Yes. While ketamine is active, it weakens the brain’s ability to pause, weigh risks and think about what happens next, so a person may agree to things or take risks they would normally avoid. With repeated use, everyday judgement can also become weaker, making it harder to stick to plans, manage money, or make careful decisions about work and relationships. This happens because the part of the brain that helps with planning and self-control is affected by the drug.
Why does Ketamine make it hard to focus?
Ketamine blocks some of the signals brain cells use to communicate, especially signals carried by glutamate, which is important for attention and learning. When those signals are blocked, the brain cannot hold a thought, follow a conversation, or keep track of a task properly. The effect is strongest while the drug is active, but with repeated use, focus can stay poor for days or longer, because the brain needs time to recover its normal way of working.
Can Ketamine change the way you think?
Yes, it can. Ketamine changes how the brain puts together what you see, hear and feel, and it can make thoughts feel loose, strange or hard to follow. It can make time feel different, make familiar things feel unreal, and make it hard to tell what is real from what is imagined. With repeated use, thinking can become slower and less clear in everyday life, and a person may find it harder to plan, solve problems or make sense of new information.
Can Ketamine affect memory and learning?
Yes. Memory and learning depend on the brain forming strong links between brain cells, and glutamate plays a central part in that process. Ketamine blocks glutamate signals, so new information is less likely to be stored properly. People who use ketamine often may forget appointments, names and instructions, and may find it harder to learn new skills at school or at work. Some of this improves after stopping, but the recovery is slow and may not be complete after very heavy, long-term use.
