Chapter 118. Brain Interventions as Therapy

1. The medical model views psychological disorders as mental illnesses that can be treated with the same methods used on physical illnesses, such as drugs, surgery, and electrical or mechanical stimulation. Each of these methods attempts to alter the functioning of the brain and, in some cases, even the structure of the brain.

2. The easiest way to change brain functioning is with psychoactive drugs that influence the way neurons communicate. Some drugs are agonists, enhancing the action of the brain’s own neurotransmitters. Other drugs are antagonists, blocking neurotransmitter action. Each drug is designed to target one of the symptoms of psychological disorders.

3. In the 1930s, some physicians experimented with psychosurgery—removing or destroying portions of the brain—as a drastic way of altering brain function. The most common surgical method was frontal lobotomy, which cut the connections between the limbic system (involved in emotion, motivation, and memory) and the frontal lobes of the cerebral cortex (involved in making decisions and planning for the future). Although this procedure did seem to calm some agitated patients, it also altered the patient’s intelligence and personality. Lobotomies fell out of favor in the 1970s, and are rarely performed today.

4. In the 1930s, another controversial treatment passed electricity through the brain, disrupting the normal activity of the brain for about a minute. This method, called electroconvulsive therapy (ECT), sounds like a barbaric punishment. But as ECT has been refined over the decades, it has become the single most effective treatment for major depressive disorder, especially in serious cases that do not respond to drug therapy.

5. Because ECT causes massive disruption to the electrical activity of the brain, sometimes producing memory loss, researchers tried to find a less drastic way of "resetting" the brain’s neural circuits. One such method, repetitive transcranial magnetic stimulation (rTMS), shows promise as a treatment for major depressive disorder and some disorders related to anxiety. This method runs electrical current not through the brain, but through a wire coil positioned near the person’s head. This generates a magnetic field that penetrates targeted regions of the brain’s cerebral cortex, changing the pattern of neural activity and possibly stimulating the growth of new neural connections.

6. Even though rTMS is less disruptive than ECT, rTMS still affects millions of neurons. In contrast, deep brain stimulation (DBS) can target a specific brain region, influencing only a few thousand neurons. This is possible because thin electrodes are inserted into the brain itself and deliver a weak electrical pulse directly to the neural circuits that are known to be involved in major depressive disorder or other psychological disorders.