‘Tis the season to be jolly - but only for some of us. It’s also the season where one in six of us in the West are overwhelmingly, debilitatingly depressed. In fact, so prevalent is depression that it is predicted to overtake heart disease as the number one illness of our times.
True clinical depression, like most illness these days, is considered largely our ancestor’s fault. The entire edifice of standard treatment for depression rests upon the theory that depression results from a chemical imbalance within the brain, which in many circles is considered to be largely hereditary.
A chemical imbalance
Most of the millions of people diagnosed as suffering from clinical depression are told they are low in a neurotransmitter called serotonin, which is largely responsible for mood. For decades, the medical solution has been to offer up a drug to counteract this poor genetic roll of the dice.
This view of the origin of depression mirrors that of virtually all of medicine, which maintains that blueprint of our life and health lies in our DNA, the genetic coding that supposedly holds a fixed menu of our potential for health or illness.
My heart problem is like dad’s, who had a dicky ticker; I’m likely to get breast cancer because it’s what my grandmother died of. We look upon ourselves in a sense as victims—victims of our genetic history.
The fact is ‘chemical imbalance’ theory of depression never been convincingly proven in any peer-reviewed study anywhere. Researchers comparing the cerebrospinal fluid of clinically depressed and suicidal patients have found absolutely no differences in their serotonin levels, compared with those of healthy controls.
Even when of healthy participants in medical trials have had their serotonin levels deliberately lowered, they have failed to become depressed; when depressed people have been given huge increases of serotonin their symptoms have not improved.
Indeed, the bible of the psychiatric community, The Textbook of Clinical Psychiatry, refers to the theory of serotonin deficiency as “an unconfirmed hypothesis”.
Some forward-thinking researchers are re-examining the serotonin issue — in fact the entire theory of why depression occurs — in light of work such as that which has just emerged from Northwestern University.
The genetic short straw
Joan Chiao, an assistant professor of psychology at the Weinberg College of Arts and Sciences at Northwestern, was fascinated by the genetic roll of the dice signified by the gene (STG), which is responsible for transporting serotonin.
STG comes in two different flavors —the short and long allele — but the short allele, like its name, represents the short straw. This variation carries the major ‘on’ switch for depression; anyone with this gene who goes on to experience multiple life stresses is thought to be overwhelmingly likely to spiral into major depression.
Chiao and her colleagues are part of the new field of cultural neuroscience, which examines mental health across nations and individual social groups. One of the greatest distinctions in any culture is how someone thinks of himself — as an individual or mainly in relation to a group.
In Chiao’s study, she and her colleagues first began by differentiating the cultural values of 29 countries, including the US, the major European countries, South Africa, Eastern Europe, and also South Asia, East Asia and South America. They examined the degree to which each population was individualistic or collectivistic – that is, whether their cultures place greater emphasis on the individual or the group.
“People from highly individualistic cultures like the United States and Western Europe are more likely to value uniqueness over harmony, expression over agreement, and to define themselves as unique or different from the group,” Chiao noted. We are defined by our distinctiveness.
In collectivistic societies, such as those of East Asia, on the other hand, higher value is placed on social harmony rather than individuality. The culture encourages behaviors and practices that endorse interdependence and group cohesion. These people are largely defined by the social groups to which they belong.
Chiao’s team then studied the genetic makeup of all these societies. They discovered that East Asia has a hugely disproportionate number of carriers of the short allele — at least 80 per cent of the population — who are genetically susceptible to depression.
In fact, they found a powerful association between the collectivistic tendencies of the population and the prevalence of the short allele gene. The tighter knit the population, the higher percentage of the people who carried the gene for depression.
If the genetic theory of depression is right, they should have discovered correspondingly high levels of depression among these populations.
Instead, they found the opposite: among these highly susceptible populations, the actual prevalence of depression was significantly lower than that of Western Europe or America.
Buffering from the group
Chiao believes that their surprise finding has to do with a tacit or openly acknowledged expectation of social support. “Such support seems to buffer vulnerable individuals from the environmental risks or stressors that serve as triggers to depressive episodes,” she noted.
As a rough rule of thumb,” wrote Harvard political scientist Robert D. Putnam in his book Bowling Alone (Simon & Schuster, 2002), “if you belong to no groups but decide to join one, you cut your risk of dying over the next year in half.”
Make sure this season to have yourself a friendly little Christmas.