Affect roughly 9% of adults; psychedelic research is concentrated in BPD and remains near-empty
Personality Disorders
Personality disorders are defined by rigid, long-standing patterns of thinking, feeling and relating, which makes them a tantalising and difficult target for psychedelics. The tantalising part is the theory: these drugs loosen mental rigidity and have been shown to shift personality traits, at least in other populations, so the idea of softening an entrenched pattern is genuinely appealing. The difficult part is the evidence, which is almost entirely absent. What little exists is concentrated in borderline personality disorder, which has its own page and where the direct findings are not encouraging, plus a scatter of early work in conditions like pathological narcissism. And part of this family, the disorders on the schizophrenia spectrum, carries the same psychosis caution that makes psychedelics a contraindication, not a treatment. The honest status is an interesting idea with very little behind it.
Personality disorders are enduring, inflexible patterns of inner experience and behaviour, grouped into three clusters: odd/eccentric (e.g. paranoid, schizotypal), dramatic/erratic (e.g. borderline, narcissistic, antisocial) and anxious/fearful (e.g. avoidant). Around 9% of adults meet criteria for at least one.
2
The intellectually compelling idea is that psychedelics, which temporarily dissolve mental rigidity and can shift personality traits in other groups, might loosen the entrenched patterns that define these disorders. That hope, however, has barely been tested in people who actually have a personality disorder.
3
Almost all of the real research is in borderline personality disorder, which has its own page. Even there it is near-empty and unpromising (a negative ketamine trial, a nine-person psilocybin study). For most other personality disorders there is essentially no direct evidence at all.
4
Part of this family carries a clear safety warning rather than a promise: the schizophrenia-spectrum personality disorders (schizotypal, paranoid) share the psychosis risk that makes classic psychedelics a contraindication, not a treatment, as on the schizophrenia page.
5
Established treatment for personality disorders is psychotherapy, and no drug is approved for any of them. Nothing here is an available treatment, and a couple of early trials (for example in pathological narcissism) are first steps, not evidence of benefit.
By the numbers
6
Trials tracked
as of July 2026
19
Papers tracked
as of July 2026
210
Trial participants
as of July 2026
Research Landscape
What the 6 registered trials connected to Personality Disorders look like when you line them up. Counts come from Blossom’s trial records as of July 2026.
What's live right now, and what stopped?
Sourced
Registry status of all 6 Personality Disorders trials Blossom tracks. Orange marks trials recruiting or opening.
Don't read stopped trials as failures: trials end early for funding, recruitment, and strategy reasons too. Status is as last synced from the registry; some 'recruiting' trials may already have finished.
What is Personality Disorders?
Personality disorders are a family of conditions defined not by episodes of illness but by enduring, pervasive and inflexible patterns of how a person thinks, feels, relates to others and controls impulses, patterns that deviate markedly from cultural expectations and cause real distress or impairment. They are usually grouped into three clusters: the odd or eccentric (such as paranoid and schizotypal), the dramatic or erratic (such as borderline, narcissistic and antisocial) and the anxious or fearful (such as avoidant). Together they affect roughly 9% of adults[1]Prospective cohorts, psychedelics in individuals with a personality disorder (2024).
What makes this an unusual umbrella for psychedelic research is the nature of the target. Because personality disorders are, almost by definition, about rigidity, fixed patterns that resist change, they raise an unusually direct version of the field’s central question: can a drug that temporarily loosens the mind’s habitual structures help reshape a stuck one? It is a genuinely interesting idea. It is also one that has been tested far more in theory, and in people without personality disorders, than in the patients themselves.
This page is the umbrella; the specifics live below it. By far the most-studied member of the family is borderline personality disorder, which has its own dedicated borderline personality disorder page, and we route the detail there rather than repeat it. We also flag an important boundary: some personality disorders sit on the schizophrenia spectrum, where the honest message is caution, not treatment, and connects to our schizophrenia page.
Current Treatments
For personality disorders, the evidence-based treatment is psychotherapy. This is clearest for borderline personality disorder, where structured approaches such as dialectical behaviour therapy genuinely reduce self-harm and suffering, but psychological treatment is the mainstay across the family, even where the evidence is thinner and the conditions (such as antisocial or narcissistic personality disorder) are notoriously hard to treat. These are long, relational treatments that work with entrenched patterns over time.
Medication has little to offer here. No drug is approved for the core features of any personality disorder, and where medicines are used it is mostly to manage co-occurring depression, anxiety or specific symptoms rather than the disorder itself. That pharmacological emptiness is part of what makes psychedelics interesting in principle. But it is not a vacuum, the psychotherapies, though demanding and imperfect, do work, so any novel approach has to measure up against real treatment rather than against nothing, and so far none has been shown to.
Independent Research
Exploratory Research Report
This report summarises what Blossom’s database shows about psychedelics and personality disorders, and it is a case where the idea is more developed than the evidence. Personality disorders are disorders of rigidity, and psychedelics loosen rigidity, which makes for an elegant hypothesis. But the hypothesis has barely been tested in people who have these conditions: the real research is concentrated in borderline personality disorder and is near-empty even there, the rest of the family is largely untouched, and part of it carries an outright safety warning. The honest picture is a serious idea resting on very little.
A note before the evidence
This page is a research summary, not medical advice, and nothing here is a treatment recommendation. No psychedelic is approved for any personality disorder, and for some of them, those on the schizophrenia spectrum, classic psychedelics carry a real risk of triggering or worsening psychosis. The evidence-based treatment for personality disorders is psychotherapy, and it should not be set aside for experimental options. If you live with a personality disorder, particularly one involving self-harm or suicidality, please stay connected to your mental-health team rather than experimenting with these substances.
A word on scope and numbers. Blossom tracks only a small number of papers and trials here, and most of them are about borderline personality disorder, naturalistic surveys, or mechanism. The amount of controlled clinical evidence in diagnosed personality disorders, outside the little that exists in BPD, is essentially zero. Read the counts as early interest, not as a body of treatment evidence.
The elegant idea: changing a personality
The reason this topic exists at all is a genuinely interesting piece of reasoning. Personality disorders are, more than almost any other diagnosis, disorders of fixed pattern: rigid, self-reinforcing ways of thinking and relating that have usually been in place since adolescence. Psychedelics, meanwhile, are among the few interventions shown to shift personality measurably, classic studies report lasting increases in the trait of openness after a psilocybin experience, along with reductions in rigidity. Put those together and you get an unusually direct hypothesis: a drug that demonstrably moves personality might be able to move a disordered one.
It is worth taking seriously, and worth being precise about its limits. Almost all of the personality-change evidence comes from healthy volunteers or from people with depression, not from people with personality disorders, and the changes, while real, are modest. "Psychedelics can nudge personality traits in non-patients" is a long way from "psychedelics treat personality disorders". The science of trait change is genuinely promising; its application to these specific, entrenched and often risky conditions is almost entirely untested.
Where the actual research is: mostly BPD
When you look for real clinical data in personality disorders, you find borderline personality disorder and very little else. That research has its own page, and the short version is sobering: the only randomised controlled trial in BPD, of ketamine, was negative[1]Neuropsychopharmacology, pilot RCT of ketamine in BPD (2023), the first psilocybin study was a nine-person open-label trial in people who also had depression, and the strongest theoretical case, for MDMA, remains a review-stage argument[2]Focus (APA), MDMA-assisted psychotherapy for BPD review (2022) with a dedicated trial only now recruiting. So even the best-studied corner of this family has produced no controlled evidence of benefit.
Beyond BPD, the map is nearly blank. The most direct umbrella data are naturalistic cohort studies of people with a personality disorder who used psychedelics[3]Prospective cohorts, psychedelics in individuals with a personality disorder (2024), which are uncontrolled and self-selected and can only generate hypotheses. There are isolated, intriguing fragments, a case report of repeated low-dose LSD helping a complex personality disorder[4]Front Psychiatry, repeated low-dose LSD for a complex personality disorder, case report (2020) notable because the benefit appeared without strong acute drug effects, but a case report is the weakest form of evidence, and one swallow does not make a treatment.
A new frontier, and a hard one: narcissism and Cluster B
The genuinely new development is that interest is starting to reach beyond BPD into the rest of the dramatic-erratic cluster, including the disorders that are usually considered hardest to treat. Early research on ceremonial ayahuasca for narcissistic personality and antagonistic traits[5]J Personality Disorders, ayahuasca and narcissistic personality/antagonism (2023), and a first trial of MDMA-assisted therapy for pathological narcissism, are testing whether emotion-opening psychedelics can reach conditions where the core problem is often a defended lack of insight. It is a bold idea.
It is also one to watch with particular care. Disorders like narcissistic and antisocial personality disorder differ from BPD in a crucial way: the person is frequently not in acute distress and may have little motivation to change, which is part of why they are so hard to treat and why their effects on others can be serious. Whether a single profound experience can shift that, or whether it simply produces a temporary softening that fades, is completely unknown. These first studies deserve attention precisely because the stakes and the uncertainty are both high.
The part of the family that is a contraindication
One section of this umbrella must be read in the opposite spirit to the rest. The Cluster A personality disorders, schizotypal and paranoid in particular, sit on the schizophrenia spectrum, sharing some of its biology and its proneness to distorted perception and thinking. For these conditions, the relevant lesson is the one from the schizophrenia page: classic psychedelics can trigger or worsen psychosis, and a history of psychotic-spectrum problems is a standard reason to be excluded from psychedelic research. Analyses of the psychiatric risks of psychedelic use[6]J Psychopharmacol, psychiatric risks for worsened mental health after psychedelic use (2024) reinforce that, for vulnerable individuals, harm is a real outcome.
So "psychedelics for personality disorders" is not one message but two, pointing in opposite directions. For the trauma-linked, emotion-dysregulation disorders, there is a hopeful (if unproven) hypothesis. For the schizophrenia-spectrum disorders, there is a warning. Collapsing the two into a single optimistic headline would be both inaccurate and, for the people in the second group, potentially dangerous.
Reading this honestly
So where do personality disorders sit? They are home to one of the field’s most elegant ideas and least of its evidence. The thought that a personality-changing drug might treat a disorder of personality is serious and worth pursuing, and it is finally beginning to be tested directly, in BPD and now, tentatively, in narcissism. But almost nothing has yet been shown to work; the best-studied corner has a negative trial; the trait-change science that inspires the whole enterprise comes mostly from people without these disorders; and a meaningful part of the family is a contraindication rather than a candidate. For people living with a personality disorder, the truthful message is that this is an interesting and respectful area of early research, not a source of available treatments, and that the proven psychotherapies, undramatic as they are, remain the real route to change.
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No controlled evidence in personality disorders. The interest is conceptual (psilocybin can shift personality traits such as openness, though mainly in other populations) plus naturalistic cohort data and a small open-label study in BPD with co-occurring depression. There is also a signal that personality-disorder features can blunt the response. A hypothesis, not a treatment. (The prior "High/Large" rating was unsupported.)
The most theoretically promising for the trauma-linked, emotion-dysregulation disorders (above all BPD), based on its effects on emotional openness and attachment. But the evidence is rationale, not results: dedicated trials in BPD and in pathological narcissism are only now under way, with nothing reported yet. (The prior "High/Large" rating was unsupported.)
Studied mainly in BPD, where the only randomised trial was negative for suicidal ideation, depression and BPD severity. Real-world use targets co-occurring depression rather than the personality disorder itself. Not shown to treat any personality disorder.
No controlled evidence in personality disorders. The interest is conceptual (psilocybin can shift personality traits such as openness, though mainly in other populations) plus naturalistic cohort data and a small open-label study in BPD with co-occurring depression. There is also a signal that personality-disorder features can blunt the response. A hypothesis, not a treatment. (The prior "High/Large" rating was unsupported.)
The most theoretically promising for the trauma-linked, emotion-dysregulation disorders (above all BPD), based on its effects on emotional openness and attachment. But the evidence is rationale, not results: dedicated trials in BPD and in pathological narcissism are only now under way, with nothing reported yet. (The prior "High/Large" rating was unsupported.)
Studied mainly in BPD, where the only randomised trial was negative for suicidal ideation, depression and BPD severity. Real-world use targets co-occurring depression rather than the personality disorder itself. Not shown to treat any personality disorder.
Small MagnitudeLow EvidenceLow Consistency
Published research
4
linked papers
4
clinical papers
0
syntheses
Latest linked paper 2023
Registered research
2 registered trials
2 recruiting/opening
158 combined reported enrollment
Highest Phase II
Psilocybin and Personality Disorders
Psilocybin carries the most conceptually interesting case here, because of what it does to personality itself. In studies of healthy volunteers and people with depression, psilocybin has been associated with lasting shifts in personality traits, notably increases in openness, which is exactly the kind of change a rigid personality disorder might in principle benefit from. The leap, of course, is from "changes traits in other people" to "treats a personality disorder", and that leap has not been made. The closest direct data are naturalistic cohort studies of people with a personality disorder who used psychedelics[1]Prospective cohorts, psychedelics in individuals with a personality disorder (2024), which are uncontrolled and self-selected.
Clinically, the only structured psilocybin work in this family is the small open-label study in borderline personality disorder with co-occurring depression, covered on the BPD page. And a note of caution cuts against the optimism: analyses of how pre-treatment clinical presentation shapes the psilocybin experience[2]J Clin Psychopharmacol, pretreatment clinical presentation and psilocybin experience (2025), together with evidence that personality-disorder features predict weaker antidepressant responses, suggest the very traits that define these disorders may complicate, not ease, treatment. Psilocybin in personality disorders is a genuinely intriguing idea at a very early stage.
MDMA is the strongest theoretical fit for the trauma-linked, emotion-dysregulation end of the family, particularly borderline personality disorder, because it reduces fear and increases emotional openness and trust. A review of MDMA-assisted psychotherapy for BPD[1]Focus (APA), MDMA-assisted psychotherapy for BPD review (2022) makes that case, and the detail is on the BPD page. What is newer, and relevant to the umbrella, is that the interest is starting to extend beyond BPD: an early trial is exploring MDMA-assisted therapy for pathological narcissism and antagonistic traits, an idea also probed in ceremonial-ayahuasca research[2]J Personality Disorders, ayahuasca and narcissistic personality/antagonism (2023).
These are first steps into genuinely under-explored territory, and they should be read as such. Treating something like narcissistic personality disorder, where the difficulty is often a lack of insight and motivation rather than overwhelming distress, is a very different and harder proposition than treating trauma. There are no efficacy results yet for MDMA in any personality disorder. The rationale is real and, for once, beginning to be tested directly; the evidence remains to come.
Ketamine’s role in this family is almost entirely about borderline personality disorder, and the headline is a negative one: the only randomised controlled trial of ketamine in BPD found no benefit over an active placebo for suicidal ideation, depression or BPD severity[1]Neuropsychopharmacology, pilot RCT of ketamine in BPD (2023). The fuller account is on the BPD page. Outside BPD there is essentially no ketamine research in personality disorders.
Where ketamine is used in people with personality disorders, it is generally aimed at co-occurring depression rather than the disorder itself, and that use is confounded and uncontrolled. Given the negative trial and the particular cautions around dissociation and impulsivity in this population, ketamine should not be presented as a treatment for any personality disorder. It is, at best, a treatment for depression that some people with a personality disorder also receive.
The near-term trajectory is a field cautiously widening its gaze beyond borderline personality disorder. Dedicated BPD trials are under way, and the first studies in other conditions, notably pathological narcissism, are beginning, which is genuinely new. There is also a slow accumulation of indirect and naturalistic data, and even isolated reports, such as a case of repeated low-dose LSD apparently helping a complex personality disorder without strong acute drug effects[1]Front Psychiatry, repeated low-dose LSD for a complex personality disorder, case report (2020), that keep the question alive without answering it.
The realistic outlook is patience and care in equal measure. The personality-change rationale is one of the more intellectually serious ideas in the field, but it has to clear two hurdles it has barely approached: showing benefit in people who actually have these disorders, and doing so safely in a group that includes high suicidality (in BPD) and psychosis-spectrum vulnerability (in the Cluster A disorders). Work on the psychiatric risks of psychedelic use[2]J Psychopharmacol, psychiatric risks for worsened mental health after psychedelic use (2024) is a reminder that, for parts of this family, the more likely effect is harm. The honest outlook is real scientific interest, almost no clinical evidence, and a strong case for proceeding slowly.
Industrial Landscape
Interest in this area comes mostly from academic researchers drawn to two things: the elegant idea that a drug which changes personality might help disorders of personality, and the challenge of populations that mainstream trials excluded. Commercial development is minimal, because the conditions are heterogeneous, stigmatised, hard to treat and legally sensitive. Lived-experience advocates, especially in the borderline community, are an important voice, often rightly wary of a field that has historically described their conditions as untreatable and might now overcorrect into hype.
For an honest broker, personality disorders are a place to resist a seductive story. "Psychedelics change personality, so they should treat personality disorders" is a clean, appealing line, and it runs far ahead of the evidence; worse, applied carelessly it points these powerful drugs at some of the most vulnerable and, in the Cluster A disorders, most contraindicated people in psychiatry. The responsible position is to find the idea genuinely interesting, to support the careful early trials now starting, and to be unambiguous that, for now, proven psychotherapy is the treatment and psychedelics are an open and partly cautionary question.
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