Does Depression “Run in Your Family”?
Does depression “run in your family”? Has anyone in your past generations, especially parents and grandparents, ever been diagnosed with depression? People diagnosed with depression (or indeed, other “mental illnesses”), or showing some symptoms of depression, are sometimes asked this question by a medical doctor or psychiatrist. Why? Because of the assumption that depression, or at least some predisposition to depression, could be inherited. This is the “nature” part of the “nature versus nurture” debate, very much at the core of the field of behavioural genetics. Since the “it runs in your family” concept relates to genetics and helps justify the use of psychiatric medication for depression, it might be helpful to understand where this idea originated.
Eugenics: Sterilize the “Degenerate”, the Poor and Criminals
Sir Francis Galton (1822-1911), a cousin of Charles Darwin, came up with the “it runs in your family” concept after reading Darwin’s seminal book, On the Origin of Species. Galton applied Darwin’s theory of evolution to his study of the British elite. Seeing trends and connections down family lines of the British elite, he came up with this idea of improving the human race which involved identifying the biologically unfit with mental disorders that exhibited “degeneracy” – even poverty. While physical features – your height, hair color and more – were considered genetically inherited, his idea that mental and character attributes were also largely inherited was new, but soon accepted by a growing number of academics and scientists. Human abilities and character were soon considered more genetic than previously thought. Apparently “madness” in those days – which we would understand today as deep emotional pain and inner conflict – was considered a family line’s last step in progressive deterioration. In Galton’s era, a person as diagnosed today with bipolar disorder and suffering deeply from say repeated past sexual abuse would be classed as a “degenerate” and having “bad genes”. Such a person (could it be you?) would be best removed from the larger population’s gene pool. This was the beginning of eugenics (“good genetics”) in the human population. Following the basic principles of population genetics, Galton advocated selective breeding, that is, intermarriage only of people with the “better” genes. Soon there were eugenics conferences organized to promote this new ideology.
Galton’s ideas were exported and further developed in the U.S. Early eugenics conferences advocated the sterilization of Americans in order to reduce the percentage of “defectives” in the population to an “acceptable level.” In 1927, the U.S. Supreme court passed laws for the sterilization of people with mental deficiency since it was considered genetic. The state of Oregon passed its sterilization law in 1917, and until it was repealed in 1983, over 2300 people in Oregon had been forcibly sterilized. The law applied to ” … feeble-minded, insane, epileptic, habitual criminals, moral degenerates and sexual perverts … “ In many states, Americans judged as mentally ill were even prohibited from marrying.
Some researchers claimed that criminality has a genetic root, or at least a predisposition. In 1907, Indiana became the first state in the U.S. to pass a law permitting compulsory sterilization of “confirmed criminals” who were deemed by physicians as showing no hope for improvement. Such people should not be allowed to procreate, it was argued, since their “bad genes” should be progressively removed from the population. What does this say for responsibility and one’s will? If criminal behaviour is genetic, how can anyone be punished for it? Is white-collar crime “as genetic” as that of a serial killer or a terrorist? Does the serial killer have several “major genes” and the white-collar criminal have many “minor” genes? If so, how many? The more one reflects on this ideology, the greater the ethical, moral and logical problems and paradoxes. A scholarly and critical review of the supposed evidence that “defective genes” causes criminal behaviour reveals that the supporting evidence and methodology, including that of twin and adoption studies, is flawed and inconclusive.
“… the evidence from twin and adoption studies does not support the existence of a genetic predisposition for any type of ‘criminal’, ‘psychopathic’, or ‘antisocial’ behavior, however it may be defined at any given time in any given society.” Jay Joseph, 2003, The Gene Illusion, Chapter 8, Is Criminal Behavior in the Genes? ppg. 240-263.
Why Not Genes for Atheism, Voting Liberal or Greed?
Well, thankfully the sterilization laws have been repealed and anyone with a mental illness is free to enjoy marriage like anyone else. But the basic reasoning is still flawed and simplistic. Any family history or pattern could also be environmental or a learned behaviour, or influenced by prenatal psychology or social forces or a mixture. Just because members of the same family for generations are Anglicans, it does not mean that there is a gene for Anglicanism. The same may be said for membership in a political party. Who would ever suggest there is a gene for Conservatism or Liberalism that governs voting behaviour? After all, “it runs in families.” Could there be a gene for atheism if for generations in a family no one had any faith or belief in God? But we then need an “atheism rating scale” – hardcore atheists who consistently denounce any and all religions are assigned “9”, and individuals who are quiet skeptics and just do not believe in God are assigned a “1”. Are there genes for impoliteness, arrogance, or snobbery, which has certainly been known to characterize whole families for possibly centuries?
Why not study the genetics of greed? One could construct a checklist to measure different scores for greed (twenty-five to thirty for really greedy, sixteen to twenty-four for moderate greed, nine to fifteen for sometimes greedy, and one to eight for possibly generous or at least averse to greed) and then compute the heritability for families and relatives with varying scores for greed. Why focus on the pathological side of life, the negative emotions, moods, or behaviours? Why not do the same for joy, gentleness, or compassion? If we studied the genetics of generosity, a useful numeric could be one’s total charitable donations each year – it could be easily computed for families and may well show a significant “heritability'”. Why not consider any of these behaviours? Because these are not mental illnesses for which a prescription is needed.
The Genetics of Spirituality
In case you think that my suggestions above are “far-fetched”, be aware that the latest scientific claim is that even spirituality has a genetic root due to the “God gene”. Apparently the VMAT2 gene (vesicular monoamine transporter) has been linked to spirituality, defined as the ability to experience self-transcendence. People with cytosine in that spot on their VMAT2 gene ranked higher on the self-transcendence test than those with adenine. The researcher confined himself to just 9 genes (0.025 per cent of all genes), those known to regulate brain chemicals known as monoamines. Incredibly, this has led to a proposal to develop a vaccine (see the short video!) to turn religious fundamentalists into more normal individuals. Spirituality can now be measured on a rating scale with fourteen and up for “highly spiritual,” twelve to thirteen as spiritually aware, eight to eleven for those with average spirituality who could do better, six to seven for practicing empiricists who don’t experience self-transcendence, and one to five for skeptics who resist developing any spiritual awareness. Apparently being drawn to God in the first place is “hard-wired” into our genes. But some people become religious late in life, others become atheists after leaving home. VMAT2 turns on or off?
This entire line of research falls apart in many respects. What if you define spirituality as loving your neighbour, obeying Jesus while walking in the light as Jesus is in the light (1 John 1:5-10)? The self-transcendence test for spirituality is biased, since it assumes a more eastern concept of spirituality based on meditation and some “higher consciousness.” People respond to God due to grace—not genetics—and resist Him due to hardness of heart and sin—not adenine in VMAT2. The research showed correlation – but correlation is not causation. What about all the other thousands of genes that were not looked at? This is all incredibly reductionist as it is incredible. But if the genetics of spirituality seems so “far-fetched”, why do we not consider the genetics of depression in the same way?
But What Is a Gene?
Any simple Google search will show many hits for supposed genes, gene interactions, “‘genomic predictions”, single nucleotide polymorphisms (SNPs) and a lot more. Many of those who argue for the genetics of mood swings and so forth are relying on the commonly held belief that “one gene leads to one effect.” Remember your high-school genetics? Most scientists believe that a section of DNA has a specific effect on some part of the organism, like hair colour, width of one’s big toe, size of one’s belly button, eye colour. If this is not always true, the arguments for the genetics of emotions and behaviours start to crumble.
Ironically, molecular genetics is steadily undermining the “gene” concept. If you are “genetics-challenged,” then the world of molecular markers, functional genomics, transposons, restricted fragment length polymorphisms (RFLP), single nucleotide polymorphisms, quantitative trait loci (QTL), linkage blocks, and so forth sounds daunting. But please read on anyway!
Professor Ellen Keller at MIT, in her very readable book “The Century of the Gene“, shows how contrary to popular opinion, simply knowing the sequence of one’s amino acids doesn’t give an understanding of biological function. Her book covers a lot of what I have seen as a PhD in quantitative genetics for the last forty years. Amidst all the gene sequencing, geneticists are less sure of where a gene begins and ends on a chromosome. Recently discovered regulator genes that control the rate of protein synthesis control the effects of other genes. Many genes are actually split and “occur” in several places on a chromosome. Alternative gene splicing causes the same sequence of “genes” to make proteins in different ways, while the one and same “gene” can actually make different proteins.
To make matters more confusing, the same protein can have different functions depending upon the context. Repeated genes, redundant genes, overlapping genes, cryptic DNA, nested genes, multiple promoters, and antisense transcription add even more complexity. Each of us has many defective genes “covered up” by normal ones. Due to different DNA sequences between everyone’s genome (all one’s chromosomes), we differ by about three million nucleotides to the next person. Then there are different DNA variations of the same gene. This does not even consider one’s all-important interaction with the environment during one’s development.
The classical “gene” concept has worked well for single-gene disorders like Tay-Sachs, Huntington’s disease, cystic fibrosis, and more—but these are rare examples. A “gene” or “genes” for depression or mood swings or spirituality, for example, is borderline illusion. Researchers often claim to have found “a gene” for some behaviour or emotion only to have it contradicted later or simply never repeated. Considering all the genetic complexity above, the difficulty in actually “measuring” depression and the fact that we all have a soul and a spirit, the genetics of depression (and joy, greed, spirituality, compulsive shopping, etc.) is entirely suspect and flawed. For even more reasons, I showed earlier that schizophrenia is certainly not genetic. No need to be “on the meds for life”!
“Go with the Flow” – But Where Will it Take You?
I went on a canoe trip in Saskatchewan with some friends many years ago. It was a nice, warm, relaxing summer day as we were quietly paddling along a rather peaceful river. We were having great fellowship and could also hear a few birds and the occasional beaver flapping his tail on the water. No one in our group had canoed this river before. There was a slight sound up ahead, and the water seemed to pick up just a bit in speed. But we were having such a great, relaxed time that nobody noticed. A few minutes later, we turned a bend, and suddenly we heard the sound of rushing water. The current quickly became very strong, and ahead of our canoes were rapids and what appeared to be a small (hopefully!) waterfall. No one was talking any more! Three of our canoes, including mine, managed to avoid getting capsized—probably more luck than skill! Two canoes capsized in trying to avoid a few large rocks, and four people ended up in the water. One person unfortunately lost his glasses.
Why mention this story? Because those who simply advocate “it runs in families” or the other common arguments or beliefs for the genetics of mood disorders or human behaviour probably don’t realize where this thinking will lead. The belief that mood disorders and other human behaviours are highly inherited ultimately leads into a huge quagmire. Man, who was made a little lower than the angels, now becomes just a little higher than his DNA. If the genetics of behaviour and character is accepted in principal, then why not declare a master race? Indeed, shockingly, the eugenics ideas of Galton can be traced to the US, wherein the laws of California in the early 1900s influenced Nazi Germany.
Ideas have consequences, sometimes unintended. There are times when taking a concept to its logical conclusion is a good test of whether the concept has any truth in it. A most fundamental question is “what is the nature of man”? Not surprisingly, Galton wrote to Darwin that in spite of his Christian upbringing, “the traditional biblical arguments made him wretched”. It is far, far better and safer to view all people as created in the image of God (Gen. 1:27), of equal worth to be loved by God the Father (John 3:16; 2 Pet. 3:9), and meant for peace and wholeness in a relationship with Him and others (John 10:10). The reality and power of Christ’s Presence with the Spirit to heal and transform people (Eph. 3:14-21) is light years beyond anything this world offers. I have seen this first-hand many times.
Many Christian authors concur with the “it runs in families” concept. Although family relationships and other factors play a role, since depression runs in families, it is argued, some family members may be “born with a genetic vulnerability to depression.” (Stephen Arterburn, 1992, Hand-Me-Down Genes and Second-Hand Emotions, ppg. 70, 82). Medically speaking, tendencies for mood disorders are genetic “because the problem runs in families.” (Grant Mullen, 2003, Emotionally Free: A Prescription for Healing Body, Soul and Spirit, page 35).
Mendel was an Augustinian monk. How ironic it would be if the Church unwittingly replaced the doctrine of grace with the laws of Mendel.