In the grim, garbage-strewn streets of Gotham, a city teetering on the edge of dystopia, lives a man named Arthur Fleck. His story is not one of a battle against a caped crusader—Bruce Wayne is still just a boy—but a far more harrowing war waged within the confines of his own mind. The film masterfully avoids placing a neat diagnostic label on him, yet his struggles provide a powerful lens through which we can explore the devastating manifestations of severe mental illness. This is an examination of a man’s descent, where the villain is not just a person, but the disorder and the societal system that failed him.

A Laughter Like Sobbing

Arthur dreams of being a stand-up comedian in a city that has forgotten how to laugh. He watches the "Live! with Murray Franklin" show with his mother, escaping into a fantasy world where he is celebrated and loved. In reality, his attempts at humor are disastrous, and his most prominent trait—his laugh—is a source of agony, not joy.

We see it erupt at the most inappropriate times: when he’s confronted on a bus, or when he witnesses harassment on the subway. This is not mirth. This is an uncontrollable, painful explosion of sound that contorts his face and ends in a gasping cough, more akin to sobbing. He even carries a small, laminated card to explain his condition to bewildered strangers, noting he has a neurological disorder. This key symptom strongly points to Pseudobulbar Affect (PBA), a neurological condition characterized by involuntary, sudden outbursts of crying or laughing. It is often the result of a brain injury or neurological disease—a critical detail when we later learn about Arthur’s past. His laughter is a physical manifestation of immense psychological distress, a nervous system under a pressure it cannot possibly bear.

The Cracks in Reality

Arthur’s world is a fragile construct, and as the narrative unfolds, we realize we cannot always trust what we see. His disorder is marked by more than just PBA. At first, his daydreams seem distinct from his reality; he knows he is only imagining himself in the audience of Murray’s show. However, the lines blur until they vanish completely.

His tender, supportive relationship with his neighbor, Sophie, feels genuine. We believe she cares for him, sees his pain, and even attends one of his performances. The eventual reveal that none of it was real—that it was all a vivid hallucination—is a chilling look into the severity of his detachment from reality. These hallucinations appear to intensify after he loses access to his seven different medications, a testament to how crucial psychiatric care was in keeping him tethered, however loosely, to the world.

Beyond hallucinations, Arthur is consumed by delusions—unshakeable beliefs that defy reality. We observe two primary forms. First, paranoid delusions manifest in his growing conviction that he must fight back against an unjust world. This escalates from a vague feeling of being wronged to a messianic mission to spark a revolution, a cause for which he is willing to commit murder. Second, he displays delusions of grandeur, a belief in one’s own exaggerated importance. This is initially seeded by his mother, Penny, who convinces him that the wealthy and powerful Thomas Wayne is his father. When that fantasy is brutally shattered, the delusion of grandeur doesn't disappear; it transforms. He no longer needs a powerful father because, after his violent acts make headlines, he believes he has become a powerful figure in his own right. He finally feels that he exists.

The Wounds of a Broken Childhood

Arthur’s problems are deeply rooted in a childhood devoid of safety or love. His mother, Penny, was herself a patient in a psychiatric hospital, diagnosed with paranoid psychosis and narcissistic personality disorder. We see these traits reflected disturbingly in Arthur. Pathological narcissism, as seen in Penny, often involves a lack of empathy, vindictiveness, and the perception of others as mere tools. While Arthur’s condition is complex, we see this coldness and vindictiveness emerge from behind his pain as his illness progresses.

More damning is the revelation of his upbringing. Penny, his adoptive mother, allowed her partner to subject Arthur to horrific physical abuse. He was once found chained to a radiator, suffering from a significant head injury. This brain trauma is a plausible organic cause for the pseudobulbar syndrome he exhibits. His mother’s note that he was “always a happy boy” is retroactively horrifying; his “happiness” was likely the uncontrollable laughter of a neurological disorder born from violence.

A Possible Diagnosis

Observing the full constellation of his symptoms—paranoid delusions, vivid hallucinations, social and emotional withdrawal, and disorganized thinking, all layered over a history of severe trauma—a diagnosis of Paranoid Schizophrenia seems probable. Schizophrenia has a known genetic component, and while Penny was not his biological mother, we know nothing of his biological parents, who may have passed on a predisposition. Furthermore, significant head trauma in childhood is recognized as a potential environmental trigger for the development of psychosis in vulnerable individuals.

When Arthur stops his medication, he claims he feels better, that he has a “new strength.” This isn't recovery; it's a shift into a more euphoric, manic state. The medications that suppressed his symptoms for years are gone, and their discontinuation unleashes the full force of his disorder. He dances after committing murder and prepares for his television appearance with a terrifying zeal. His life, he concludes, is not a tragedy but a "fucking comedy." This is the chilling endpoint of a mind and a man let down by everyone and everything, a personal story of illness that becomes a catalyst for city-wide chaos.

References

• American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.).

  This manual is the foremost authority in the United States for psychiatric diagnoses. The criteria listed for Schizophrenia align closely with Arthur Fleck’s symptoms, including the presence of prominent delusions (persecutory, grandiose), hallucinations, and social dysfunction. The text provides the specific diagnostic framework that a real-world clinician would use to assess such a condition.

• Ahmed, A., & Simmons, Z. (2013). Pseudobulbar affect: prevalence and management. Therapeutics and clinical risk management, 9, 483–489.

  This peer-reviewed article offers a clinical overview of Pseudobulbar Affect (PBA). It explains that the condition is a disorder of emotional expression, not a mood disorder, and is characterized by uncontrollable, often contextually inappropriate, episodes of laughing or crying. Importantly, the authors discuss its link to traumatic brain injury (TBI) and other neurological diseases, which directly supports the theory that the head trauma Arthur suffered in childhood could be the cause of his signature pathological laughter.