By DAPHNE MERKIN
Published: July 28, 2012
SOME of my happiest moments have been spent as a mother. I say this despite being a constitutionally unhappy person who has fought all her life against an encroaching darkness — and not always successfully. Angie Wang
· Health Guide: Depression
Those moments stretch back decades — to, say, summer mornings in a rented cottage on Block Island, when I, an inveterate late sleeper, would be awakened shortly past dawn by my 10-month-old daughter, Zoë, standing up in her crib, cheerfully gurgling at me, raring to begin the day. And they are as recent as last week when Zoë, now 22, and I engaged in one of our long analytical talks about the movie we had just watched, and I was struck by the ways in which her mind works differently from mine and by certain perceptual habits we have in common.
My battles with chronic depression have landed me in a psychiatric unit several times since my daughter was born. She was 6 months old when I was first hospitalized, 7 years old the second time, and 18 the last time. I worry about the impact on her of those separations, relatively short as they were, and I worry more about the effect of living with a mother who often fights to keep afloat. (I have been divorced from Zoë’s father since she was about 4, and we have spent large periods of one-on-one time together.) Although I know that depression is not something you can catch from another person, like chickenpox, I fear that my susceptibility will somehow “rub off” on my daughter — that she might pattern her responses to life’s inevitable difficulties after my own.
I will never forget the time when she was a little girl, no more than 6 or 7, and announced one evening after I had gotten angry with her about something, that she was taking a kitchen knife to bed in order to kill herself. I remember that she was wearing her favorite pajamas, which were imprinted with pink bows, when she said this and how incongruous such a declaration seemed, coming from someone whose bedtime was 7:30.
Panic-stricken, I rushed after her into her room, pried away the knife and attempted to soothe her, and read to her until she fell asleep. She never repeated this gesture or anything like it, but I feel intensely guilty even now as I recall it, since I can only assume that she modeled her behavior on some distraught conversation she had overheard in which I threatened to take desperate action. As Zoë has grown, it has become harder to shield her from my periods of acute despair; she has heard me express suicidal wishes and, at the worst points, has observed me sink into virtual immobility and wordlessness.
I have been thinking about such matters lately because of the comedian Sarah Silverman’s remark on a TV talk show that she didn’t want to have a child of her own and preferred to adopt for fear of passing on her depression. Much as I sympathize with Ms. Silverman’s trepidations (assuming they were meant to be taken seriously), I think they suggest the undue influence we assign to genetic determinability. This is a fairly recent phenomenon, one that can be accounted for by the latest pendulum swing in the nature versus nurture debate.
The 1950s and ’60s saw a consuming belief in the importance of environmental factors in the shaping of personality; this led to such handy but reductive concepts as the “schizophrenogenic” mother and Bruno Bettelheim’s theory that withholding mothers caused autism. Now, with greater knowledge of how our brains work, we live under the tyranny of the biological. Where once we feared the input of our own unwitting selves, we now fear the imprint of our chemically ordained destinies.
So how heritable is depression? There is no single genetic marker for it; current research shows that multiple genes probably contribute simultaneously to its chances of being transmitted. Research is hard in this area because we can’t perform the perfect experiment — separating identical twins at birth and raising them in different homes to see which get depressed and which don’t. Scientists can, however, compare identical twins (conceived from the same egg and sperm) with fraternal twins (conceived from different eggs and sperm) and see how they differ. Such twin studies have recently concluded that the heritability of depression is about 40 percent.
This may sound fairly high, until you realize that heritability refers only to an underlying risk of depression, not to depression itself. “It’s not Mendelian genetics,” observes Dr. Andres San Martin, a New York City psychopharmacologist. “Causality is a result of interaction,” he asserts, shaped by “multiple factors on multiple levels.”
Probably the most basic error we make is in trying to frame the puzzle of how human character evolves in stark oppositional terms — nature or nurture — rather than seeing it as an inextricable mix of things. Dr. Robert Klitzman, a professor of clinical psychiatry and director of the master’s program in bioethics at Columbia University, observes that “people misunderstand genetics.” “They want to read genetic tests as black and white,” he adds. “Doctors see it much more like predicting the weather.”
Dr. Klitzman points out that people find genes a handy receptacle for blame in what he calls a high-stakes “responsibility game.” We want to know, in other words, if it’s our fault or not our fault — or perhaps our mother’s fault. If it’s your genes, you’re not culpable, and what a relief that is. When Prozac emerged, the biological notion of depression gained traction and the stigma about the disease correspondingly went down. So there are lots of incentives to link psychological disorders to genetic factors, even if it means overstating or blurring reality.
Though science has made rapid advances in the culling of genetic information, it is rare for a common disease to be attributable to one gene; Tay-Sachs, cystic fibrosis and sickle cell anemia are among the few examples. In other instances, even when a gene has been isolated (as is the case with Alzheimer’s), the gene doesn’t begin to account for all cases of those diseases. You can have the mutation and not get the disease, or get it and not have the mutation. It’s all in the intertwining of nature and nurture. Researchers, for example, have reported that the combination of the monoamine oxidase A gene, dubbed “the warrior gene,” and a background of childhood abuse may help explain instances of aggressiveness and antisocial behavior.
Biology is not destiny: a child born of any parent (depressed or not depressed), has about a 16.5 percent (one in six) chance of experiencing a depressive episode during his or her lifetime. Depression is not a single phenomenon, which makes it all the more difficult to figure out the cause.
What’s clear is that for most people, depression appears to be more a result of environment and experience than of one’s inherent nature, which means that “upbringing,” to use an old-fashioned word, still matters. If you do things halfway right and there are no unforeseen traumatic occurrences, like crucial losses or undue stresses, chances are good — better than 50-50 — that the child of a depressed parent will grow up to be a nondepressed adult. That statistic would never persuade me to opt out of the experience of bringing a child of my own into the world. If anything, Zoë has been more of an antidepressant than the best cocktail of meds that I’ve been offered.
Until more compelling genetic information becomes available, it seems that the best we can do is to keep our children’s predispositions in mind while focusing on the pieces of the developmental puzzle over which we can exert control. (This includes being attuned to your child’s nature, especially when it differs from your own.)
Betwixt my lurches into the dark, I gave my daughter a lot of love, which my own parents weren’t capable of doing (a fact I take to be at the root of my own depression, given that neither of them was depressed). These days, Zoë’s no longer the bright-eyed early riser she was as an infant, and she’s got her share of problems, just like the rest of us. But, so far a lifelong case of the blues does not appear to be one of them.
The author of a forthcoming memoir on living with depression.