When the Truth Sounds Like a Delusion: The Cost of Getting Diagnosis Wrong
What happens when a therapist mistakes an improbable story for a delusion? A patient can spend years being treated for a disorder they do not have while the trauma they actually experienced goes untreated.
Katie Rose, LCSW is a manhattan based psychotherapist with over a decade of experience treating individuals and couples in NYC.
That is the danger of confusing what seems unlikely with what is untrue.
Delusions live in the space between what is true and what feels true. Sometimes that distance is enormous—like believing you are being monitored by aliens from another planet. Other times, the distance is paper-thin, because the truth itself sounds almost impossible.
For clinicians, that distinction matters. A story can sound implausible and still be true. And when a therapist decides that something cannot have happened simply because it seems unlikely, the consequences can be profound.
What is delusional disorder?
Delusional disorder is a psychotic disorder characterized by persistent delusions—strongly held beliefs that are not consistent with reality. The belief persists despite evidence that contradicts it.
For a diagnosis of delusional disorder, clinicians also have to consider whether the belief is better explained by another mental health condition, a substance, a medical condition, or a culturally or religiously accepted belief.
Delusional disorder is different from schizophrenia in several important ways. People with delusional disorder may otherwise function relatively well, and prominent hallucinations, disorganized speech, and negative symptoms associated with schizophrenia are generally absent.
The important clinical point is this:
A belief should not be labeled a delusion merely because a clinician finds it unusual, improbable, or difficult to believe.
What is the difference between bizarre and non-bizarre delusions?
Traditionally, clinicians have distinguished between bizarre and non-bizarre delusions.
A non-bizarre delusion involves something that could theoretically happen. For example, a person might believe they are being followed by the FBI.
A bizarre delusion involves something that could not realistically happen—for example, believing that aliens have implanted a device in your brain so they can transmit your thoughts to another planet.
The distinction is important because non-bizarre beliefs can be particularly difficult to evaluate. They describe events that are possible.
And that creates a dangerous clinical trap:
Possible does not mean delusional. Improbable does not mean impossible.
Sometimes the unbelievable thing really happened.
The case that changed how I think about diagnosis
In graduate school, one of my professors frequently used cases from her private practice to illustrate clinical concepts. She had practiced in New York City for more than 20 years and often told us she had “seen it all.”
In 2014, she presented a case involving an adult patient she had treated for approximately a decade.
The patient had entered therapy after reporting a sexual assault that had allegedly occurred during adolescence. They described classic trauma symptoms: nightmares, intrusive memories, avoidance of places associated with the alleged perpetrator, profound shame, and hopelessness.
There was one problem, according to the professor:
The assault had never happened.
The alleged perpetrator was an A-list celebrity. Based on what the professor knew about the patient's life and the celebrity's public timeline, she believed it was impossible that they could have crossed paths.
So she interpreted the patient's account as a delusion.
At the time, the case seemed like an excellent example of how difficult delusional disorder can be to diagnose. The patient's story sounded extraordinary. The belief was firmly held. And the alleged event seemed so unlikely that an experienced clinician had concluded it could not have happened.
I remember the case vividly.
I also remember the details my professor shared—the celebrity's name, personal information about the patient, and enough identifying context to make the story feel disturbingly real.
That is why I have heavily redacted the details in this retelling.
But the story did not end there.
What #MeToo revealed
In 2017, the #MeToo movement became a global force for confronting sexual harassment, sexual assault, abuse, and systems that protected powerful people.
And one of the powerful individuals exposed by that movement was the very celebrity my professor had identified.
The public allegations revealed a pattern of grooming and sexual misconduct that closely matched the patient's account—the account my professor had spent years treating as delusional.
The patient was not delusional.
The story that sounded impossible was true.
The real diagnostic mistake
The most important lesson from this case is not that clinicians should automatically believe every allegation.
It is that clinical skepticism must not become clinical certainty without evidence.
The patient had presented with a story that sounded improbable. But they had also presented with significant trauma symptoms.
Even if the patient's account had ultimately proved inaccurate, those symptoms still deserved careful assessment and treatment.
Instead, the clinician appears to have anchored on the implausibility of the story and interpreted the patient's experience through that assumption.
That is the opposite of trauma-informed care.
What does trauma-informed therapy require?
Trauma-informed care does not mean accepting every statement without question. It means understanding how trauma can affect a person's emotions, behavior, relationships, memory, sense of safety, and engagement with treatment.
It also means approaching the client with curiosity rather than prematurely imposing an explanation.
For social workers, this connects directly to a foundational principle: commitment to clients and starting where the client is.
A therapist does not have to decide immediately whether every detail of a client's story is objectively true.
The therapist does have to take the client's distress seriously.
That distinction is crucial.
Why clinicians need diagnostic humility
There is a particular danger in mental health care: the clinician's interpretation can become more powerful than the patient's own account of their experience.
Once a clinician decides, “This cannot be true,” subsequent information may be interpreted through that lens.
The patient's fear becomes paranoia.
Their certainty becomes delusion.
Their trauma symptoms become evidence of a psychotic disorder.
And the diagnosis itself can make it harder for future clinicians to reconsider what happened.
This is why diagnostic humility matters.
Experienced clinicians have seen extraordinary things. But experience should increase curiosity, not eliminate it.
“I've never seen that before” is not the same as “that cannot happen.”
What this case taught me about PTSD
The patient in this story reportedly experienced symptoms consistent with post-traumatic stress disorder (PTSD), including nightmares, intrusive memories, avoidance, shame, and hopelessness.
Those symptoms deserved attention regardless of how plausible the alleged assault initially seemed.
That is one reason trauma-informed practice matters even when a clinician does not primarily work with people who identify as trauma survivors.
Trauma does not always arrive in a story that is easy to believe.
Sometimes it arrives wrapped in details that make the listener uncomfortable.
Sometimes it sounds improbable.
And sometimes, unfortunately, the truth really is stranger than fiction.
There is also a lesson about confidentiality
There is another part of this story that has stayed with me: confidentiality is more than a legal standard. It is also an ethical responsibility.
A clinician can avoid technically violating a privacy law and still fail to treat a patient's story with the care and dignity it deserves.
Teaching cases can be valuable. They allow future clinicians to learn from real-world complexity.
But the people whose lives become those teaching cases are not hypothetical characters.
They are patients.
Their suffering is not a plot device.
And their stories deserve tenderness.
The danger of thinking you've “seen it all”
My professor taught me a great deal about clinical practice.
But the most important lesson she gave me was not the one she intended.
It was this:
Never confuse clinical experience with omniscience.
In mental health, confidence is useful. Arrogance is dangerous.
A clinician who believes they have seen every possible presentation may stop asking questions. They may rely on pattern recognition when they should be gathering evidence. They may mistake an unusual story for a pathological one.
And a patient can pay the price.
I still think about that patient—someone I never met and, ethically, should never have known about.
They deserved a clinician who could remain curious when their story sounded impossible.
They deserved someone who could say:
I don't know yet what happened. But I believe that you are suffering, and I want to understand why.
What should therapists do when a client's story seems impossible?
When a client's account seems improbable, the goal should not be to choose immediately between “true” and “delusional.”
Instead, clinicians should:
Separate the client's symptoms from the factual question. Treat distress and impairment even while evaluating the underlying account.
Ask questions rather than making assumptions. An unusual story deserves careful assessment, not automatic dismissal.
Consider alternative explanations. Psychosis is one possibility among many.
Assess for trauma symptoms independently. A patient's need for trauma treatment should not disappear because one aspect of their story is difficult to verify.
Remain aware of diagnostic bias. Once a diagnosis is assigned, confirmation bias can make contradictory information easier to overlook.
Maintain appropriate confidentiality. Teaching and consultation should protect the dignity and privacy of the person whose experience is being discussed.
Practice epistemic humility. “I don't know” is sometimes the most clinically responsible answer.
The lesson I wish every clinician remembered
The best clinicians are not the ones who have “seen it all.”
They are the ones who know that they haven't.
A patient can be mistaken. A patient can misunderstand what happened. A patient can experience psychosis. A patient can remember something inaccurately.
And a patient can also be telling the truth about something that sounds completely impossible.
Our job as clinicians is not to force every story into the category that makes the most sense to us.
Our job is to stay curious long enough to understand the person in front of us.
Because the distance between what is true and what feels true can sometimes be enormous.
And sometimes, it is almost nothing at all.
Frequently Asked Questions
Can an improbable story be mistaken for a delusion?
Yes. An unusual or improbable claim is not automatically a delusion. Clinicians need to assess the belief in context and consider available evidence, alternative explanations, cultural context, medical factors, substance use, and other psychiatric conditions.
What is the difference between delusional disorder and schizophrenia?
Delusional disorder primarily involves persistent delusions, while schizophrenia generally involves a broader pattern of psychotic symptoms and greater disruption in functioning. Schizophrenia may include hallucinations, disorganized thinking or speech, and negative symptoms.
Can someone with PTSD have unusual or strongly held beliefs?
Yes. PTSD can involve intrusive memories, nightmares, avoidance, hyperarousal, negative changes in mood and cognition, and other symptoms. The presence of an unusual belief does not by itself establish a diagnosis of delusional disorder.
Does trauma-informed care mean believing everything a client says?
No. Trauma-informed care does not require a clinician to accept every factual claim without assessment. It requires clinicians to understand trauma, avoid unnecessary retraumatization, respect the client's experience, and approach assessment with safety, curiosity, and humility.
Why is diagnostic humility important in therapy?
Diagnostic humility helps clinicians recognize the limits of their own knowledge. It reduces the risk of prematurely interpreting an unusual experience as evidence of mental illness and encourages clinicians to continue assessing new information.
What is the biggest lesson from this case?
A story that sounds impossible is not necessarily false. Clinicians should distinguish between evaluating whether a belief is accurate and evaluating whether a patient is suffering. Both require careful, evidence-based assessment.
This article was originally published on my substack!
