Psychosurgery: From Lobotomy to Deep Brain Stimulation

surgeons performing an operation — Photo: Shakirov Albert / Shutterstock

A surgeon once drilled into a patient’s skull, severed part of the brain, and won a Nobel Prize for it. Today, doctors do something similar but reversible, using tiny wires and electricity instead of a blade. That is the strange, decades-long story of psychosurgery.

Story Snapshot

Portuguese neurologist Egas Moniz performed the first leucotomy, an early form of lobotomy, in 1935 and published his results in 1936.
Lobotomies spread widely through the mid-1900s before a fierce ethical backlash shut most of them down.
Surgeons later developed precise, targeted procedures and, by 1999, tested reversible deep brain stimulation for severe obsessive-compulsive disorder.
Modern deep brain stimulation research shows real symptom relief but still raises tough questions about consent and long-term effects.

How A Nobel Prize Winner Started The Lobotomy Era

Egas Moniz began operating on psychotic patients in November 1935, cutting the connections between the frontal lobes and deeper brain structures. He published his findings the next year, describing a surgical treatment for certain psychoses. The procedure, called leucotomy, aimed to calm severe mental illness by disrupting brain pathways tied to emotion and thought. It marked the formal start of frontal lobe surgery as psychiatric treatment.

Moniz’s technique spread fast. Doctors across the world adopted lobotomy as a fix for conditions ranging from depression to schizophrenia, often with little proof it worked and no reliable way to measure the damage it caused. Thousands of patients underwent the surgery through the 1940s and 1950s. The procedure was irreversible, and outcomes varied wildly from patient to patient.

The Backlash That Nearly Ended Brain Surgery For Mental Illness

By the mid-1900s, the lack of rigorous testing and the harsh side effects of lobotomy sparked outrage. Reports of personality changes, emotional flatness, and permanent disability turned public opinion against the practice. Lawmakers in the United States even called for a ban, and the era of unchecked psychosurgery ended in widespread condemnation. Doctors and ethicists vowed history should not repeat itself.

That backlash forced a reset. Surgeons who still believed brain-based treatment held promise for severe mental illness had to prove their methods were precise, evidence-based, and reversible. This shift pushed the field toward stereotaxis, a technique that lets surgeons target tiny, specific brain regions instead of cutting broadly through the frontal lobes.

From Irreversible Cuts To Reversible Electrical Signals

The next leap came in 1999, when a research team led by Bart Nuttin used deep brain stimulation instead of permanent lesions to treat severe, treatment-resistant obsessive-compulsive disorder. Electrodes placed in the internal capsule delivered electrical pulses that could be adjusted or turned off entirely. Early results showed real improvement in several patients, though some needed unusually strong stimulation to see benefits.

That trial opened the door to a wave of research. Anterior cingulotomy and capsulotomy, both narrower descendants of the old lobotomy, remain in use today for the most severe, treatment-resistant cases of obsessive-compulsive disorder and depression. Deep brain stimulation later expanded further, with the Food and Drug Administration approving it for movement disorders like essential tremor in 1997 and Parkinson’s disease in 2002.

What The Evidence Shows Today

A meta-analysis covering nearly thirty studies found deep brain stimulation produced significant, measurable drops in obsessive-compulsive symptoms, along with improvements in anxiety and depression scores. Separate research tracking patients over time found depressive symptoms improved by as much as 67 percent in some cases. These numbers give the treatment real credibility, something lobotomy never earned through honest testing.

Ethicists still argue over how to classify this modern treatment. Some researchers insist deep brain stimulation is fundamentally different from old psychosurgery because it is precise and reversible. Others counter that it is still a form of psychosurgery carrying old and new ethical concerns that deserve serious attention, especially around consent from vulnerable psychiatric patients. That debate deserves respect, since altering brain circuits, even reversibly, is not a decision to take lightly. Contemporary ethical standards now demand strict attention to patient autonomy and informed consent, a hard-won lesson from the lobotomy era that should never be forgotten.