Multiple sclerosis can cause hallucinations, though the symptom catches many patients and even some clinicians off guard. Psychotic symptoms, including hallucinations, occur in people with MS at roughly two to three times the rate seen in the general population, according to epidemiological studies. The causes range from demyelinating lesions in specific brain regions to medication side effects to sleep disorders that tag along with the disease. Understanding why hallucinations happen in MS, and recognizing that they are more common than once thought, matters because they are treatable once correctly identified.
How Common Are Hallucinations in MS
For a long time, psychosis in MS was considered rare, almost a curiosity confined to scattered case reports. That view has shifted. More recent population-level studies found that psychotic symptoms in MS show up at two to three times the rate expected in the general population, putting the prevalence well above what “rare” would suggest.1PubMed Central. The spectrum of psychosis in multiple sclerosis: a clinical case series Hallucinations are one piece of that broader psychotic spectrum, which also includes delusions and paranoid thinking. Other psychiatric conditions frequently seen alongside MS include anxiety disorders, bipolar disorder, and substance misuse.2PubMed Central. Neuropsychiatric Symptoms of Multiple Sclerosis: State of the Art
The real numbers are probably higher still, because hallucinations are one of the symptoms people tend to keep to themselves. Someone who hears a voice or sees something that is not there may worry about being labeled with a psychiatric illness on top of an already demanding diagnosis. Clinicians do not always screen for psychotic symptoms during routine MS visits, so the gap between what patients experience and what gets documented is likely substantial.
Where Lesions Form Shapes What You Perceive
MS attacks the insulating myelin around nerve fibers, and the location of the resulting lesions largely determines which symptoms appear. When it comes to hallucinations, three brain areas stand out.
- Temporal lobe: Lesions here are linked to psychotic features that look similar to schizophrenia, including auditory hallucinations and paranoid delusions. One documented case involved a young man with MS who developed first-episode psychosis with acute lesions visible in his temporal lobe on imaging.3PubMed Central. Temporal lobe lesions and psychosis in multiple sclerosis
- Brainstem and cerebellar peduncles: Damage here can produce a phenomenon called peduncular hallucinosis, which typically involves vivid visual scenes, sometimes with an auditory component, that the person recognizes are not real. A reported case described a 27-year-old woman with MS lesions in the superior cerebellar peduncle and pontine tegmentum who experienced both visual and auditory hallucinations that she could self-identify as unreal.4Acta Neurológica Colombiana. Peduncular hallucinosis in multiple sclerosis, a rare symptom in demyelinating disease
- Optic nerve and visual pathways: When MS-related optic neuritis causes significant vision loss, the brain’s visual cortex can become overactive in the absence of normal input. This produces a condition called Charles Bonnet syndrome, discussed in more detail below.
The important takeaway is that the type of hallucination often tells you something about where the disease is active. Auditory hallucinations and paranoid thinking point toward cortical involvement, especially temporal regions. Vivid visual scenes that the person knows are not real suggest brainstem or visual pathway involvement. That distinction directly influences how the symptom should be managed.
Charles Bonnet Syndrome and Optic Neuritis
Optic neuritis is one of the most recognizable symptoms of MS, and when it causes substantial vision loss, it can set the stage for a type of visual hallucination that has nothing to do with psychiatric illness. Charles Bonnet syndrome occurs when the brain’s visual cortex, deprived of its normal input, starts generating images on its own. The mechanism is sometimes compared to a radio producing static when it loses a signal: the visual processing regions fill in the gap with internally generated patterns or scenes.
The hallucinations in Charles Bonnet syndrome are often strikingly detailed. Patients report seeing intricate patterns, faces, animals, or full scenes. A key feature is that these hallucinations are typically not distressing. People recognize that what they are seeing is not real, and there are no accompanying delusions or confusion. One case report described a woman with MS whose optic neuritis left her temporarily blind in both eyes; during the blind period, she experienced vivid visual hallucinations for about two weeks that resolved as her vision returned.5PubMed. Charles Bonnet syndrome associated with a first attack of multiple sclerosis She had no psychiatric history and no cognitive problems, making Charles Bonnet syndrome the clear explanation.
A more recent case added detail to this picture. Visual evoked potentials confirmed severe optic nerve damage in a patient whose hallucinations matched the Charles Bonnet pattern, supporting the interpretation that deafferentation of visual inputs to the brain was driving the hallucinations rather than any primary psychiatric condition.6The Primary Care Companion for CNS Disorders. Charles Bonnet Syndrome in a Patient With Multiple Sclerosis: A Rare Presentation of Complex Visual Hallucinations Associated With Optic Neuritis Recognizing Charles Bonnet syndrome matters because it does not require antipsychotic medication. Treatment focuses on the underlying vision loss and reassuring the patient that the hallucinations are a known, benign neurological phenomenon.
Medications That Can Trigger Hallucinations
Some drugs prescribed to manage MS symptoms can themselves cause hallucinations, creating a confusing clinical picture where it is unclear whether the disease or the treatment is responsible.
Amantadine, commonly prescribed to treat MS-related fatigue, is a notable culprit. In cases where kidney function declines, amantadine can accumulate to toxic levels because the body clears it through the kidneys. One report described a woman with MS who developed florid visual hallucinations after acute kidney impairment raised her amantadine levels; the hallucinations resolved completely once the medication was stopped.7PubMed. Amantadine toxicity causing visual hallucinations In another case, cognitive deterioration, balance problems, and hallucinations in a person with MS all disappeared after discontinuing amantadine that had been prescribed years earlier, suggesting that toxicity can build gradually and mimic disease progression.8PubMed. Delayed amantadine toxicity causing apparent progression of multiple sclerosis
Baclofen, a muscle relaxant widely used for MS spasticity, presents a different risk. The hallucinations here tend to happen not when a person is taking the drug, but when they suddenly stop. Abrupt withdrawal from oral or intrathecal baclofen has been documented to cause visual hallucinations, likely driven by changes in brain receptor activity after chronic exposure to the drug is suddenly removed.9Functional Neurology. Hallucinations after abrupt withdrawal of oral and intrathecal baclofen The practical implication is that baclofen should always be tapered rather than stopped abruptly.
These medication-related cases are important because they are the most fixable cause of hallucinations in MS. Adjusting a dose, switching a drug, or monitoring kidney function can make the hallucinations disappear entirely.
Sleep Disruption and Hypnagogic Hallucinations
MS takes a well-documented toll on sleep architecture. Fatigue is one of the most common complaints in the disease, and behind that fatigue often lie identifiable sleep disorders. Narcolepsy, although uncommon in the general population, has been reported in association with MS, and it brings its own brand of hallucinations. Hypnagogic hallucinations (occurring as you fall asleep) and hypnopompic hallucinations (occurring as you wake up) are classic features of narcolepsy, along with sleep paralysis and sudden muscle weakness triggered by emotion.10IntechOpen. Sleep Disorders in Multiple Sclerosis
These hallucinations differ from the other types discussed so far. They are tied to the boundary between sleep and wakefulness, and the person experiencing them often recognizes that they were in a transitional state. They might see a figure at the foot of the bed or hear someone call their name as they drift off. The experiences can be unsettling, especially for someone already managing a chronic neurological condition, but they stem from disrupted sleep regulation rather than from demyelinating lesions or drug effects. Treatment typically targets the underlying sleep disorder rather than the hallucinations themselves.
The Steroid Paradox
High-dose corticosteroids are the standard first-line treatment for MS relapses. They are also well known for causing psychiatric side effects, including insomnia, mood swings, mania, and psychosis. This creates a genuine dilemma when someone with MS develops hallucinations during an acute relapse: are the hallucinations coming from the new demyelinating lesion, or from the steroids used to treat it?
The answer is sometimes both, and sometimes the relationship is paradoxical. Steroids do have a propensity to exacerbate psychosis, which typically argues against using them in someone who is already hallucinating. But if the psychosis is driven by active demyelination, reducing that inflammation with steroids could theoretically improve the psychiatric symptoms even as the drug carries its own psychiatric risks.11PubMed. Steroid treatment of acute psychosis associated with multiple sclerosis One case report documented the successful treatment of acute psychosis in an MS patient using corticosteroids, supporting the idea that when the brain inflammation is the root cause, treating the inflammation resolves the psychosis.12Primary Care Companion for CNS Disorders. A Case of Psychosis in a Patient Concurrently Diagnosed With Multiple Sclerosis Treated Successfully With Corticosteroids
This is a judgment call that requires careful clinical reasoning. If a patient develops new psychotic symptoms during steroid treatment, the clinician has to weigh the timing, the location of lesions on imaging, and the patient’s psychiatric history to decide whether to continue, reduce, or stop steroids. There is no simple algorithm.
How Hallucinations in MS Are Treated
Treatment depends entirely on the cause. For medication-related hallucinations, adjusting or stopping the offending drug is usually sufficient. For Charles Bonnet syndrome, no psychiatric medication is needed; managing the underlying optic neuritis and educating the patient are the priority. For sleep-related hallucinations, treating the sleep disorder comes first.
When hallucinations are driven by MS lesions themselves, the evidence, while limited to case reports and small series, points toward two approaches. If the psychosis coincides with an active relapse and new lesions, corticosteroid treatment aimed at reducing the demyelination can resolve the psychiatric symptoms along with the neurological ones. When antipsychotic medication is needed, low-dose atypical antipsychotics have shown benefit in individual cases.12Primary Care Companion for CNS Disorders. A Case of Psychosis in a Patient Concurrently Diagnosed With Multiple Sclerosis Treated Successfully With Corticosteroids Aripiprazole at a low dose improved paranoid and hallucinatory symptoms in one patient within days.13Journal of Psychiatric Practice. Use of aripiprazole in a patient with multiple sclerosis presenting with paranoid psychosis Risperidone depot has also been reported as effective.14PubMed. Risperidone depot in the treatment of psychosis associated with multiple sclerosis — a case report
A persistent problem in this space is the near-total absence of large-scale clinical trials. The evidence consists almost entirely of case reports and small case series. No randomized trial has compared antipsychotic agents head-to-head in MS patients, and there is no consensus guideline specifying which drug to use first. Clinicians draw on individual case data and general antipsychotic principles, choosing agents with lower risk of worsening fatigue or mobility problems that are already prominent in MS.
Untreated psychotic symptoms carry real consequences beyond the hallucinations themselves. People experiencing untreated psychosis in MS are more likely to have difficulty sticking to their disease-modifying therapies, which increases disability over time and erodes quality of life.1PubMed Central. The spectrum of psychosis in multiple sclerosis: a clinical case series Getting the psychiatric symptoms under control is not just about comfort; it directly affects how well someone can manage their MS.
Telling MS Hallucinations Apart From Primary Psychiatric Illness
One of the trickiest diagnostic questions is whether a person with MS who starts hallucinating has developed a new psychiatric disorder, like schizophrenia, that happens to coexist with their MS, or whether the MS itself is producing the psychotic symptoms. The distinction is not academic: it changes the treatment plan.
Several features point toward MS as the cause. If the hallucinations begin during or shortly after an acute relapse, especially when new lesions are visible in the temporal lobe or brainstem on MRI, the MS is the likely driver. If the person has no prior psychiatric history and no family history of psychotic illness, that further tilts the balance toward an MS-related explanation. Age of onset matters too: schizophrenia typically emerges in the late teens to early twenties, while MS-related psychosis can develop at any point during the disease course and often appears later than primary schizophrenia would.
In contrast, if psychotic symptoms predate the MS diagnosis by years, run in the family, or persist even when the MS is stable with no new lesions, a co-occurring psychiatric condition becomes more plausible. The reality is that some patients fall into a gray zone where the two overlap. Someone with a genetic vulnerability to psychosis might have it unmasked or worsened by MS-related brain changes. These cases require collaboration between neurology and psychiatry, a partnership that does not always happen smoothly in practice.
Why Peduncular Hallucinosis Gets Missed
Peduncular hallucinosis deserves special attention because its features make it easy to overlook or misinterpret. The hallucinations are typically visual, vivid, and fully formed: people report seeing animals, people, or elaborate scenes. They often occur in the evening or at night. And the hallmark feature is that the person experiencing them usually knows the visions are not real. That preserved insight is both a clinical clue and a practical barrier to diagnosis, because a person who knows their hallucinations are not real is less likely to bring them up with a doctor.
The underlying cause is damage to the brainstem structures, particularly in the pons and midbrain, which disrupts the neural circuits that normally regulate visual processing during wakefulness. In MS, demyelinating plaques in the cerebellar peduncles or pontine tegmentum can produce exactly this pattern.4Acta Neurológica Colombiana. Peduncular hallucinosis in multiple sclerosis, a rare symptom in demyelinating disease When a patient reports vivid nighttime visions that they recognize as unreal, and MRI shows brainstem lesions, peduncular hallucinosis should be high on the list of explanations. No antipsychotic is typically necessary; treating the underlying relapse and monitoring the lesions is the standard approach.
What Hallucinations Feel Like in Context
Living with MS already means managing an unpredictable disease that attacks different systems at different times. Adding hallucinations to that experience introduces a layer of fear and confusion that goes beyond the perceptual disturbance itself. People worry about losing their minds on top of losing their mobility. They worry that reporting hallucinations will lead to a psychiatric diagnosis that overshadows their neurological care, or that their MS medications will be changed in ways they do not want.
These concerns are not irrational. Psychiatric symptoms do sometimes redirect clinical attention away from the MS itself, and the stigma surrounding hallucinations is real. For people on disease-modifying therapies who are carefully managing relapses, the prospect of adding an antipsychotic with its own side-effect profile feels like another burden. Clinicians who actively ask about perceptual disturbances during appointments, and who frame the question in a matter-of-fact way, are more likely to hear about symptoms that would otherwise go unreported. Normalizing hallucinations as a known neurological complication of MS rather than treating them as a sign of separate psychiatric pathology makes it easier for patients to speak up and get appropriate help.