Your brain and psychotherapy

Content provided by the Faculty of the Harvard Medical School

Your brain and psychotherapy

Are there consistent underlying features of therapeutic change?

Early in his career, Sigmund Freud conceived what he called a project for a scientific psychology, linking an understanding of the mind to an understanding of the brain and its functions. He soon abandoned the effort because he realized that too little evidence was available. But psychotherapists know that psychiatric disorders always involve activity in the brain. In this era of psychopharmacology, brain imaging, and therapeutic electrical and magnetic stimulation of the brain, scientists are beginning to get some glimpses of what that activity might be.

One source of those insights is the use of positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and other scanning techniques to see how psychotherapy itself affects the brain. The findings to date — preliminary and often conflicting — usually involve two brain regions: the limbic system, a center for the integration of memory and emotion; and the prefrontal cortex, which supplies the capacity for long-term planning, judgment, and self-control.

Studies have concentrated on three disorders:

Phobias. When a person with performance anxiety has to give a speech or a person who fears snakes is confronted with one, brain scans show rising blood flow and energy consumption in the amygdala, a center for fear and anger, and sometimes in the insula, a region that registers disgust and pain. Treatment with either cognitive behavioral therapy or an antidepressant lowers this activity. Treatment also seems to cause changes in several parts of the prefrontal cortex, and in this case the effects of medication and psychotherapy may be different.

Obsessive-compulsive disorder (OCD). When the symptoms of OCD — unwanted, uncontrollable, repetitious thoughts that result in compulsive actions — are highly active, so is a brain circuit connecting part of the frontal cortex with the basal ganglia, a region involved in the coordination of movements. Successful treatment with either psychotherapy or antidepressants reduces that activity.

Depression. Results are conflicting. In some studies, treatment with cognitive behavioral or interpersonal therapy seems to heighten activity in the prefrontal cortex and decrease it in the limbic system, including the amygdala. Other studies suggest that what changes is relative activity levels in different parts of the prefrontal cortex. Different kinds of depression or depressions with different causes may create different patterns.

The meditating brain

Mindfulness meditation and related techniques for regulating attention are said to produce serenity, heightened awareness, and other therapeutic effects in the short and the long run. According to a review, though, brain imaging and EEG recordings have shown no consistent correlations between these reported effects and blood flow, electrical rhythms, or energy consumption in various parts of the brain.

So far, the most striking result has come from a study finding that the cerebral cortex was thicker than average in people with years of meditation experience. But since there were no controls, it’s not clear that meditation deserves the credit. Research on these questions will become more important as meditation is further incorporated into psychotherapy.

Psychoanalysts have begun to take an interest in relating discoveries about brain function to their own ideas about the defenses of the ego, the influence of the unconscious, and the effects of emotionally charged memories. Freud said that the aim of psychoanalysis was to replace the id, or “it” — unconscious forces and impulses — with ego, or “I.” Some psychoanalysts are suggesting parallels in the idea of reasserting the rule of the prefrontal cortex over the limbic system. Psychoanalysts and others trying to reconcile and unify Freud’s ideas with recent brain science have taken up his abandoned project for a scientific psychology by forming the International Neuro-Psychoanalysis Society (www.neuro-PSA.org/uk/nPSA).

Another mystery brain scientists are trying to penetrate is the placebo — the sugar pill or saline injection that seems to heal through faith and hope. One experiment found that in Parkinson’s disease, both the medication L-dopa and a placebo relieved symptoms by raising the level of the neurotransmitter dopamine in the region affected by the disease. But in a study of depression, drugs and placebos had opposite effects on brain activity. In patients who responded to antidepressants, blood flow increased in the prefrontal cortex; in patients who responded to a placebo, it decreased.

In another depression study, activity in the amygdala and nearby limbic regions decreased when patients responded to an antidepressant but not when they responded to a placebo. Different underlying processes might be at work, and different kinds of depression might be responding to the two treatments. One theory is that placebos work from the top down, altering expectations by changing activity in the prefrontal cortex, while medications work from the bottom up, influencing the limbic system first.

Psychotherapy shares with placebo the themes of hope and belief. Time and research may tell whether, when psychotherapy heals, its effect on the brain is like placebo, medication, or neither. If psychotherapy and drugs are complementary in their action on the brain, that might explain why a combination of the two is often the most effective treatment for a psychiatric disorder.

The ultimate goal of understanding psychotherapy’s effects on the brain is to influence the choice of treatments. A study published in 2006 found that certain brain activity patterns predicted which depressed patients would and would not respond to cognitive behavioral therapy. Some enthusiasts have imagined a day when patients could be assigned to psychotherapy, medication, or other treatments on the basis of brain scans. Some even suggest the possibility of monitoring the progress of psychiatric treatment by tests of brain health resembling the exercise stress tests by which cardiologists judge changes in heart health.

We need a much more detailed understanding of how the brain works, and much more specific testing, to achieve that end. Today, it’s difficult to get consistent results from brain scans. The symptoms of psychiatric disorders are too ambiguous. The brain changes that underlie the symptoms are too subtle and variable. And brain scans are not sensitive enough to pick up key differences.

Scientific curiosity about brain changes in psychotherapy derives from the understanding that everything we think of as being the mind happens in the brain. To explain the complicated process of psychotherapy this way may seem utopian. Nevertheless, in a Newsweek interview, Eric Kandel, who won the Nobel Prize for his work on brain changes that accompany memory and learning, has said, “We need to look for the biological effectiveness of all kinds of psychotherapy in the same way we do for drugs. I think that will be the leitmotif of the next 15 years. If we can do it, we will revolutionize the field.”

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Last updated:	August 21, 2006