Many adolescents are curious about medications and may be tempted to experiment with drugs they find at home. Unfortunately, even a single pill can sometimes produce unexpected and distressing consequences.
A Lesson Michael Will Never Forget
Michael was a 17-year-old honor student with no history of mental illness. One afternoon, while looking through his parents’ medicine cabinet, he noticed a prescription bottle labeled: «Take one tablet as needed for severe anxiety and agitation.»
Curious about its effects, he swallowed one pill.
Within an hour, Michael felt unusually calm and sleepy. He decided to take a nap. But when he woke up several hours later, something was terribly wrong.
He felt an overwhelming inner restlessness unlike anything he had ever experienced. Sitting still became almost impossible. He paced around the house, shifted constantly from foot to foot, and found it painful to remain seated for more than a few moments.
As the evening progressed, his anxiety intensified. He became increasingly irritable and unusually argumentative with his parents. That night, he slept very little.
By the following morning, Michael’s behavior had become alarming. He remained unable to sit still, felt intensely anxious, and became aggressive when confronted about his behavior. His parents barely recognized the son they knew.
Fearing that Michael was experiencing his first psychotic break, they rushed him to the emergency department.
Was Michael Developing Psychosis?
The answer was no.
Michael was not psychotic, nor did he need antipsychotic medication.
What he was experiencing was akathisia, a common but often overlooked side effect of the medication he had taken: Haloperidol.
Because Haloperidol can remain in the body for several days, the symptoms can persist long after a single dose.
What Is Akathisia?
The word akathisia comes from the Greek words meaning «not sitting.» The name is fitting because people experiencing akathisia feel an intense inner urge to move and are unable to remain still.
Patients often pace, rock back and forth, shift their weight repeatedly, or constantly move their legs. Many describe the sensation as unbearable.
Beyond physical restlessness, akathisia can trigger severe anxiety, irritability, agitation, and, in some cases, aggressive behavior.
Among antipsychotic medications, Haloperidol is one of the drugs most commonly associated with akathisia. Studies suggest that even a single dose can trigger akathisia. [1] Fortunately, akathisia typically resolves once the medication is discontinued.
Why Akathisia Is Often Misdiagnosed
One of the greatest dangers of akathisia is that its symptoms can resemble the early stages of a psychiatric illness. [2]
A patient who suddenly becomes restless, agitated, anxious, and aggressive may be mistakenly thought to be developing psychosis. As a result, additional antipsychotic medications may sometimes be prescribed, potentially worsening the very condition causing the symptoms. [3]
Misdiagnosis can lead to unnecessary hospitalizations, emotional distress, and prolonged suffering.
Akathisia belongs to a group of medication side effects known as extrapyramidal symptoms. Other extrapyramidal symptoms associated with Haloperidol include tremors, muscle rigidity, painful muscle spasms, and involuntary upward eye movements.[4]
Other Causes of Akathisia
Although antipsychotic medications are a common cause, they are not the only one.
Akathisia has also been reported with several classes of drugs. [2]
Among those:
- Selective serotonin reuptake inhibitors (SSRIs)
- Serotonin-norepinephrine reuptake inhibitors (SNRIs)
- Tricyclic antidepressants
- Metoclopramide and other anti-nausea medications
- Stimulants such as amphetamines
Medical conditions can sometimes produce similar symptoms as well. Parkinson’s disease and iron-deficiency anemia are among the better-known examples. [2]
Researchers believe that akathisia is partly related to disruptions in dopamine signaling within the brain, although its exact mechanism remains incompletely understood. [5][6]
The Importance of Asking One Simple Question
Fortunately for Michael, the emergency physician took the time to obtain a careful history.
Rather than immediately assuming a psychiatric disorder, the physician asked a simple but critical question: «What happened just before your symptoms started?»
Only then did Michael remember taking a pill from his parents’ medicine cabinet.
Once the medication was identified as Haloperidol, the diagnosis became clear.
Michael was able to return home. His symptoms persisted for approximately three days, then gradually improved until they completely resolved.
The Moral of the Story
For parents, medications should always be stored securely and out of reach of children and adolescents.
For teenagers, experimenting with prescription medications can be dangerous. Even a single pill can produce serious and unexpected reactions.
For healthcare professionals, Michael’s story serves as a reminder that medicine remains both a science and an art. A careful history can sometimes prevent a devastating misdiagnosis.
And for Michael, one pill was enough to teach a lesson he would never forget.
Copyright 2026 @Chris Gilbert, MD, PhD
www.psychologytoday.com
