What Is Psychosurgery?

The World Health Organization (WHO) defines the field of psychosurgery as “the selective surgical removal or destruction of nerve pathways for the purposes of influencing behavior.” Simply put, psychosurgery is brain surgery performed to treat psychiatric disorders. 

The core concept behind this type of surgery is that if certain parts of the brain are responsible for symptoms, destroying the brain tissue connecting those parts of the brain will help eliminate those symptoms.

History of Psychosurgery

To date, the most well-known example of a psychosurgery is the lobotomy. The lobotomy was developed by António Egas Moniz in the mid-1930s. He used it to "cure" a variety of mental health disorders, particularly depression and schizophrenia.

The procedure involved drilling two small holes in a patient's skull and cutting the nerve fibers that connected the front of the brain (which controls personality, decision-making and reasoning) with other regions of the brain. He believed that as new nerve connections formed, the patient's "abnormal" behaviors would stop.

In the late-1930s, neurologist Walter Freeman brought the surgery to the U.S. In an effort to “improve” Moniz’ method, he developed the ice-pick method: hammering an ice pick through the eye socket into the brain and "wiggling it around" to sever brain connections.

It should come as no surprise that hammering an ice pick directly into the brain wiggling it about, often produced serious side effects. Some patients were left severely brain damaged and hundreds died. Even those procedures that were considered successful left patients unresponsive and childlike.

Despite the irreversible effects, psychosurgery was incredibly popular in the 1930s and 1940s. An estimated 5,000 lobotomies were performed in 1949 in the U.S. It was only after antipsychotic drugs were introduced in the mid-1950s to treat schizophrenia, that the use of psychosurgery began to decline. 

Modern Psychosurgery

Although psychotherapy is still used, it is only used in extreme cases when medication and behavioral therapy has failed. Furthermore, the techniques used today are radically different than those used in the past.

Surgeons no longer blindly rummage around a person's brain with an ice pick and destroy sections as they see fit. Rather, psychosurgery now involves destroying only tiny bits of tissue by heat. The specific areas of the brain that are targeted have virtually no effect on intellectual functioning and quality of life.

However, in very rare cases psychosurgery may be used to treat the following treatment-resistant conditions: 

• Generalized anxiety disorder (GAD) 
• Major depressive disorder (MDD)
• Obsessive-compulsive disorder (OCD)

The most common psychosurgical procedures in use today are:

• Anterior cingulotomy
• Subcaudate tractotomy
• Limbic leucotomy (which is a combination of the first two)
• Anterior capsulotomy

Only anterior cingulotomy, anterior capsulotomy, and limbic leucotomy are practiced with any frequency.

Anterior Cingulotomy

While most patients with OCD eventually respond to treatment with medication and/or behavioral therapy, a small minority of people aren't so lucky. For these people, anterior cingulotomy appears to be a relatively effective treatment.

Since the 1960s, anterior cingulotomy has been used to treat patients with treatment-resistant OCD (and sometimes MDD). The procedure begins with a surgeon drilling a small hole in the patient's skull and then using a blade to allow access to the anterior cingulate cortex. A heated probe then burns away about half a teaspoon of tissue in the anterior cingulate cortex.

Studies show that up to 70% of patients with treatment-resistant OCD receive some benefit from the procedure. Although the procedure is not without side effects (including a risk of infection and seizures), the risk of experiencing these side effects is small.

Anterior Capsulotomy

Another psychosurgery procedure used for treatment-resistant psychiatric disorders is called anterior capsulotomy. Anterior capsulotomy is similar to anterior cingulotomy, but instead of targeting the anterior cingulate cortex, surgeons burn away tiny bits of tissue in a region near the thalamus (called the anterior capsule).

This surgery is effectively reduces symptoms in more than half of patients with OCD who do not respond to therapy or medication. Unlike anterior cingulotomy, anterior capsulotomy has a slightly higher risk of causing a few immediate side effects, including:

• Cerebral edema (swelling)
• Delirium (acute state of confusion)
• Headache
• Seizures
• Urinary incontinence

A surprisingly common long-term effect of this procedure is weight gain. A review of 20 studies found that after undergoing an anterior capsulotomy, almost one-third of patients gain more than 10% of their body weight.

Subcaudate Tractotomy

According to a landmark study of 208 patients in 1975, approximately two-third of patients with depression or anxiety, and 50% of those with OCD demonstrated improvement.

However, although this procedure is just as effective as the cingulotomy, it appears to cause more side effects. Approximately 2% demonstrated postoperative seizures, and almost 7% demonstrated negative personality traits after surgery.

For this reason, the subcaudate tractotomy is rarely, if ever, performed as a stand-alone procedure in the U.S.  Subcaudate tractotomy is a procedure that targets the white matter in the brain.

Limbic Leucotomy

Another important development for treatment-resistant psychiatric disorders is limbic leucotomy. Limbic leucotomy has been used since the mid-1970s to treat MDD and of course, OCD.

This procedure is essentially a combination of anterior cingulotomy and subcaudate tractotomy. It is usually done if a patient doesn’t respond to anterior cingulotomy. A 2013 study found a 73% rate of symptom improvement in patients with OCD and severe MDD who did not initially respond to anterior cingulotomy.

The side effects, which appear to be short term, include transient hallucinations, amnesia, and mania.

Recovery and Prognosis

For the vast majority of patients, response and/or recovery is a slow process. Most patients spend at least two to three weeks in the hospital following psychosurgery. Most people are able to tell if the treatment worked nine to 12 months after surgery.