Nature vs. nurture revisited: Toward a truly integrative psychiatry: CrossCurrents Autumn 2004

CrossCurrents

by Abigail Pugh

The heart is just a muscle, a powerful mass of chambers and walls. Yet popular wisdom holds that emotions live there. A happy person is "lighthearted" and a depressed one is "downhearted." Mental health professionals generally prefer to see the brain as the centre of these powerful states - and, for many disciplines, "brain" is further localized to "mind."

But is the mind an actual physical area within the human brain? Or is "mind" just a metaphor for something unplaceable - more akin to "spirit" or "soul"? Who is more qualified to study and treat devastating emotional disorders such as depression, anxiety, addiction or psychosis: the philosopher, poet, priest or counsellor interested in "mind," or the objective neuroscientist who is focused on "brain"?

Questions like these, large enough to encompass so many ancient dualisms - mind/body, nature/nurture, art/science - are starting to take a central place in mental health research. Thanks to newer research technologies, answers may be coming that will unify the many ideological and methodological rifts dividing mental health care.

The fact that Freudian psychoanalytic methods traditionally involve talking rather than taking medication has led to a popular conception of psychoanalysis as an arts- as opposed to a science-based therapy, inhabiting the opposite end of the spectrum of neuroscientists and biological psychiatrists. Yet Freud's non-reliance on drugs stemmed in large part from the primitive and non-specific medications available at the time, and his inability to explain the mechanisms of the "talking cure" stemmed, not from his lack of interest in brain functioning, but from the absence of technologies for viewing its structures and metabolism. In his 1920 book, Beyond the Pleasure Principle, Freud wrote, "The deficiencies in our description would probably vanish if we were already in a position to replace the psychological terms with physiological or chemical ones."

2000 Nobel prize-winning neuroscientist and psychiatrist Dr. Eric Kandel of Columbia University in New York, says much the same thing: "Insofar as psychotherapy works, it's got to be doing something [in the brain]. And if it does, one should be able to detect it with various imaging techniques. To me it's really a question of time and resolution in finding it. Everything that we think of as mind is a series of functions carried out by the brain." As an example, Kandel mentions the fact that those who experience severe anxiety, such as panic attacks or post-traumatic stress disorder, tend to show high levels of activity in an area of the brain called the amygdala. "Understanding the biological basis of emotion will lead to better treatments, and brain imaging will lead to better understanding of outcomes of psychotherapy." (See sidebar for explanation of brain imaging techniques.)

Toronto-based psychoanalyst Dr. Norman Doidge agrees: "Curious psychotherapists must be interested in the brain, and curious neuroscience researchers must be interested in mind."

Dr. Ari Zaretsky, head of the Cognitive Behaviour Therapy Clinic at Sunnybrook and Women's College Health Sciences Centre in Toronto, reinforces the point: "Recent research is demonstrating that talk therapies create measurable changes in the brain. This fact should not be surprising, given that psychotherapy is really nothing more than a complex form of experiential learning, and learning creates lasting biological changes."

At the heart of talk-based therapies is the notion that significant improvements to mental health and well-being can occur through verbal and emotional transactions in a controlled environment, leading to changes in deeply ingrained thoughts and behaviour. Underlying the biological interventions such as medication, electroconvulsive therapy and brain surgery is the assumption that mental disorders have an organic root, and must be addressed biologically. Modern psychotherapies often combine drug- and talk-based approaches in the belief that they mutually reinforce each other's benefits, a position that, since the advent of more effective medications, is now mainstream practice.

So why have "mind" and "brain" been distinguished from one another for so long? "Mind is a biological phenomenon," explains Doidge. "There is a long history as to why we doubted this, going back to the philosopher Descartes who tried to separate mind and brain … in part having to do with the Church's belief that the mind was the soul, and hence immortal, outlasting the body, and hence immaterial."

A 2002 study by Dr. Zindel Segal, head of the Cognitive Behavioral Therapy Unit at the Centre for Addiction and Mental Health, and Dr. Helen Mayberg, a senior scientist at the Rotman Research Institute, both in Toronto, examined the effects of talk therapy on clients experiencing depression. Using positron emission tomography, they looked at the brains of clients treated with the antidepressant Paxil and those treated with cognitive-behavioural therapy (CBT). Although the two groups responded equally well in terms of symptom relief, their brains looked different after treatment: "The antidepressant drugs worked in the lower, older levels of the brain, and the CBT worked on higher levels of the brain - those involved with thinking, worrying and rumination," says Segal. In other words, the medication had a "bottom-up" effect, and the talk therapy had a "top-down" effect, but both effectively eased depression. Segal says that studies of biological effects of talk therapies are as-yet very scarce: "This work is very new. I can count the number of studies on one hand: there are three studies of depression, one study of social anxiety and one study of obsessive-compulsive disorder [treated with either cbt or interpersonal therapy]."

An entirely new scientific specialty called neuropsychoanalysis seeks to better understand and objectively measure the effects of psychoanalysis, one of the oldest talk therapies. But, as Doidge points out, this will be difficult, even with modern brain imaging: "To my knowledge, brain scan studies haven't yet been done for psychoanalytic therapies, and for good reason," he says. "Each of our talk therapies works in slightly different ways and aims at different kinds of problems." Unlike CBT, psychoanalytic treatments don't work by directly targeting pathological mood states (although they at times try to deal with some of the triggers for these states to ultimately prevent them). Analytic treatments are more focused on working through and changing mental representations, especially those formed in early life that we may not be aware of, which give rise to ongoing problems. "A change in thoughts will change a life, but as far as we know it won't change a fMRI [functional magnetic resonance imaging] because these kinds of thoughts involve very widely distributed patterns of neurons and, unlike mood states, occur very quickly," adds Doidge.

It seems that measuring the biological effects of some talk therapies may be decades away. But the process has begun and, in the case of cbt, has yielded fascinating, useful results. We may be entering a new era of truce between talk therapy and quicker-fix biomedical therapies - good news for both the mental health and addiction fields.

• Print