Factors that lead to mental illness are biological factors, environmental factors and circumstantial factors. No single one of these is the be all and end all of mental illness and generally people have two or even three of these present.
Biological factors are looking at genetics, which includes both DNA and epigenetics. DNA (deoxyribonucleic acid) is the chain of G, T, A, and C rungs that are the blueprint for making a human. Your DNA defines how to make you, while my DNA defines how to make me. Not each rung is an on switch, nor an off switch – it is far more complicated than that. The rungs bunch together and are called genes. They define how certain groups of things work, and some of these things seems quite unconnected. One of these genes in canines, for example, connect the aggressive response to the rigidity of the ear and a few other factors. When you breed aggression out of foxes, you get domestic dog looking foxes. Epigenetics is a faster environmental response system that is built into your body for how to interpret different parts of the DNA. Eating bitter plants (such as broccoli and brussel sprouts) turns more of your anti-cancer epigenes on. This isn’t changing our DNA, it is changing how our body interprets the DNA. As we get older we don’t mind bitter plants as much, as that is when we need the cancer fighting foods, while when we are younger and can be more easily poisoned by eating the wrong bitter plants, we don’t like bitter much at all. Some epigenetic switches have been found to last as little as 6 months.
What we consume and what we experience affects us. It can also affect our children. The Dutch Winter Hunger is a fascinating discovery of how epigenetics not only switch the genes on and off for one generation, but last several generations down the line. When looking at biological sources of mental illness we look at your genogram, that is your children, your siblings, your parents, your parents siblings and your grandparents. Do any of them have odd behaviours or diagnoses? If there is a few, then the odds are that your experience is being influenced by hereditary genetics. This can lead to a nature vs nurture debate, which I’ll cover a bit later when I talk about environment. This is the nature part.
Some drug use can change some of these switches. We all have some genetic switches that when flipped will promote ill health. Paracelsus points out that all drugs are poisons, what matters is the dose. That is, if the does is right, the drug is useful, if the does is wrong, it creates harm. Illicit drugs are hard to control the dose and often we take far more of them than we should or need, thus we run the risk of taking doses high enough that we promote mental illness. Getting drunk on alcohol will make most people act oddly while the alcohol is in their system, but once they sober up the expectation is that the temporary insanity will go away. Drink too much for too long and your behaviour may last longer than the alcohol in your system. Illicit drugs are more likely to create persistent effects because you’ve flipped a genetic switch (or at least, that is the current thinking on how this works). Sometimes we are poisoned by toxins in our environment and sometimes by what we choose to consume. Sometimes we pass on these altered epigenetics to our children.
The Dutch Winter Hunger, mentioned above, was directly involved with a generation of children born during an induced famine. These children were born underweight and never grew to the full height of the rest of their family. This is not too unexpected. They also had a higher incidence of illness and disease when compared to their brothers and sisters born outside of the famine. What was unexpected was that the children born to these now adult’s, who were born in relative prosperity, were also seemed to have an increase in disease (the previously thought decline in weight appears to just be a statistical anomaly that was cancelled out later), as were their children. We are waiting to find out what the next generation does. The effects of drugs and toxins that lead to poor mental health on the next generation is still being explored… watch this space. But slowly, because it takes a lot of time to breed humans. It will be interesting to see what more examination of this specific famine have. Lab tests done with animals and plants have also corroborated inter-generational epigenetic inheritance.
Environmental factors are more about society, culture, subculture and parenting. This is the nurture side of the “debate”. The debate is a bit silly. It is trying to create a false dichotomy. Is who I am a result of my nature or my nurture? The answer is both. Sometimes more one than the other, but both nonetheless.
Society is the land you are in, culture is the assumptions of your family (often based on heritage), subculture is the values of your friends and peers, and parenting is the parental environment aside from all of these. Each of these creates a set of values and problem solving strategies and assumptions within us. When they work well with our personal view of the world and interaction with events, life is generally pleasant and easy. When there is conflict between our society, culture, subculture and/or parental environment, then often we find conflict within ourselves. Sometimes one or more of these environments can be harmful to us, in which case we again find conflict within ourselves. This conflict can become behavioural or emotional (feeling) regulation issues, commonly regarded as mental illness.
Coinsider being raised in a culture that defines blue eyed people as probably possessed by demons while brown eyed people are naturally resistant to such possession. A child will not be able to inherently know that this is cultural belief is considered strange by wider society. Children often assume the beliefs of their parents and local community are true. When that grown child is arrested by blue eyed police officers for doing something that the family believes is okay, such as burning down heretical places of worship, the assumption is going to be that the blue eyed police officers are possessed by demons. If the person ever works out that the values and life assumptions given to them by their parents and community are in error, that person is going to have a tough time adjusting to society. Society is going to seem shallow and full of errors. And it is. Mostly that majority of people who grow up in mainstream society have excellent ways to excuse all of the little errors, mistakes and outrages that surround us. People who come into this society see these errors for what they are – foolish and wrong.
When our environment harms us in subtle or overt ways, we learn ways to minimise the harm and make it seem alright. We humans survive. When we find ourselves no longer in a harmful situation, we don’t adapt well to peace and safety. Many mood disorders stem from this environmental harm. Mood disorders such as anxiety, depression, post traumatic stress disorder, borderline personality disorder and so on frequently stem from surviving hostile situations and not adjusting to non-hostility.
Sometimes the environmental factor is quite short lived. At this point we steer a bit away from thinking of it as nurture and define it more as circumstantial. That is, the circumstances in which you have found yourself is very stressful. A natural consequence of high and/or ongoing stress is changed behaviour.
Each of us has a certain amount of buffer space where we can be faced with adversity and adapt and overcome it without significant effect on ourselves. Buffer space is the concept behind stress tolerance and resilience. Stress tolerance is how much stress (unbalanced pressure) we can endure before it causes us problems. Resilience is how quickly does that stress tolerance come back. Each person has a different amount of both of these – some have little, some have lots. At some point, every person’s buffer can be overwhelmed. I posted a few weeks ago about torture. The point of torture is to overwhelm a person’s buffer space. Go read that if you want to know more.
Humans break, and upon breaking they change. When this change hinders us, it promotes mental ill health.
Often we want to personalise disaster – “why is this happening to me?”, “everything comes in threes”, “it’s like the universe is out to get me”. In the vast majority of times the disasters are not personal, they just happen randomly. Human perception of random is poor. We tend to think of random as an even distribution of events rather than recognising that events clump. Consider crossing the road away from traffic lights. The drivers are not in communication with each other and they don’t care about you. They are just driving. Yet they tend to clump up together at some times and spread out at other times. This is great for us at the side of the road, we just wait for the spread out bits to cross the road, rather than cross when the cars clump together. Unless the cars clump so much that they stop, that is. Events do that too. We think the spread out bits of bad luck (that is events that we don’t like) are lucky for us while the clumped up bits feel personal, because then we have some measure of control over it… right?
When enough local events go wrong for us we use up our buffer to deal with the first few events and then fail to have the resources to manage the next few events. This is when we humans tend to fall down and fail a bit. This risks mental illness, that is behavioural change and/or perception of the world change, of either a short term or long term nature.
Each of these causes can create different behaviours and management methods of the world. When we continue to interface with the world in a mostly successful way, we call them behavioural traits and no one really cares. When we move to the next level of management, where it is going okay, but wider society thinks it is odd, we frequently call the behaviour eccentric, different, annoying and/or special. When we fail to manage okay and our life becomes disordered or intolerable for various reasons, we call that mental illness.
For some, only one of these factors contributed to their mental illness. For others a combination of factors contributed. The mental illness is not defined by the contributing factor(s), it is defined by the effect it has on you now.