People with depression commonly hear different versions of:
“Everybody goes through tough times. Everybody feels depressed, withdraws from company, loses their appetite, sleep and feels generally horrible at times, but they manage to pull themselves out of it. You need to buck up, take control of your life and get rid of your depression.”
This is extremely frustrating for the depressed person and can make them feel worse about themselves because it seems like somehow it is their own fault that they can’t get out of depression.
People with depression cannot pull themselves out of it. They cannot ‘will’ themselves out of depression. Depression is not something they can control, because depression is as much a biological disorder as say, diabetes is.
One of the problems is that the same word depression is used both for the low feeling we have for a couple of hours when we get bad news and for the biological disorder, for which the main symptoms are an overwhelming sense of sadness and a loss of pleasure in activities. They are entirely different things. The depression we refer to here is the second kind - the overwhelming, debilitating, pervasive biochemical disorder, with a genetic basis and early experience influences which makes it difficult to enjoy life; a disorder which affects 15% of the population.
A brief look at the biology of depression can help us get this distinction more clearly.
There are hundreds of neurotransmitters in our body, conveying different messages from neuron to neuron in our brains and a handful of them have been implicated in depression.
- Dopamine: Low levels of dopamine are associated with the loss of pleasure in activities and anything that used tobring pleasure earlier. So a person who is successful at work, is in a long term relationship, who seemingly has a good life, can still be depressed and unable to enjoy life, because their level of dopamine is low.
- Norepinephrine: Low levels of norepinephrine are associated with psychomotor retardation – the feeling that you don’t have the energy for anything, that makes getting out of bed and get ready for the day very difficult, the overwhelming feeling of tiredness.
- Serotonin. Low levels of serotonin are related with obsessive feelings of guilt and grief.
Hormones are chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. There are many types of hormones that act on different aspects of bodily functions and processes.
- Thyroid Hormone. The thyroid hormone is responsible for all lot of things but low levels of thyroid are associated with depression. In fact, research says that 20% of all depression is undiagnosed low levels of thyroid.
- Estrogen-Progesterone Ratio: Women have twice the incidence of depression as men. Women have higher vulnerability to depression at certain points in their reproductive life histories - menarche, during their period, after delivery (postpartum depression), menopause - all of this is associated with greater vulnerability to depression. Research has shown that the levels of estrogen, progesterone and more importantly, the ratio between estrogen and progesterone is associated with depression. Estrogen and progesterone are associated with the level of several neurotransmitters who are in turn associated with depression.
- Hydrocortisone: Hydrocortisone is a hormone released during stress. The level of this stress hormone is off the charts during depression. There is a huge neurochemical battle going on inside the heads of depressed people. If a person is exposed to a lot of hydrocortisone, they are more at risk for depression. Hydrocortisone works by affecting the dopamine levels, among others.
- Twin Studies: Depression is a genetic disorder and tends to run in families. Your chances of getting depression are higher if you have a close blood relative who has depression. If your Identical twin has depression, there is a 50% chance of you getting it. If your fraternal twin or siblings have it, you have a 25% chance of getting it. What does that tell us? That it is a genetic disorder. Also that there is a 50% chance of NOT getting it, even when your identical twin who has all the genes in common with you has it. So it has a genetic component, but it is not the only thing that matters. The relationships between genes and depression is not about absolute inheritability, it is about vulnerability.
- Gene Regulating Serotonin: A few years ago researchers found a gene involved in the levels of serotonin. There are two versions of the gene - each of us has one of the versions. The immediate hypothesis was that one of those version of the gene is responsible for depression. However, it was shown that those with the good and bad version of the gene had the same likelihood of getting depression UNLESS they had a history of exposure to major stressors – stressors like parental divorce, abuse, death of a family member in your childhood. In the people with the good version of the gene, as they have more and more traumatic childhood experiences, their risk of depression goes up, naturally, but for the people with the bad version of the gene, the rise is exponential, - they have30 times more risk than people with the good version. This gene has to do with the impact the stressors have on you in the long term.
Depression is often triggered by stressors. For a large subset of people, before their first episode of depression, something awful happens. They stay down for a long period. When they come out of the other side, they are no more at a risk for another depressive disorder than the average person. The second major stressor can trigger another depressive disorder. Once they come out of it, they are no more at a risk for another depressive incident than anybody else. Somewhere by the fourth and the fifth stress-induced depression, something in their biochemistry changes and stressors are not required to trigger depression. Depression can occur without a stressor.
What all of this shows is that depression has a biological basis and it is not something an individual can control on their own. This also highlights the importance of medication, because medication is what can control the levels of neurotransmitters and hormones in the body and maintain them at an optimal balance. The treatment of depression necessarily has to have a two-fold approach – psychiatric medication to control the levels of hormones and neurotransmitters, and counselling to help deal with life stressors. Any one approach can be ineffective without the other.