The role of the brain
During an episode of depression the brain functioning is changed, namely the neurotransmitters’ metabolism in the brain is out of balance, so too is BDNF and the maintenance of synapses.
In people with chronic depression that was initiated in childhood or adolescence, some brain structures can be smaller than expected.
(In terms of treatment, the outcome of antidepressant treatment combined with psychotherapy is generally more positive in terms of prevention of relapse than antidepressant treatment alone).
Nevertheless, the up-to-date exact mechanisms of what happens in the brain are not yet completely clear from a scientific point of view. It is likely that the concentration of neurotransmitters in the synaptic cleft is too low and that there is less BDNF available, leading to fewer synapses and a poor dendritic tree.
Certain areas of the brain seem to function differently in those who are depressed.
In this process, neurotransmitters called noradrenalin and serotonin play a part, as do many other neurotransmitters.
We have seen the different nature of causes of depression, how they interact and what they produce at the brain level. We gave some examples earlier, but here is a list of some of the most frequent causes:
- Life events – we all need time to deal and cope with some stressful life events, such as bereavement or a relationship breakdown. When these events happen the risk of developing depression increases, especially if you stop seeing your friends and family and become isolated trying to deal with your issues alone.
- Long-standing difficulties – such as financial difficulties or poverty, or taking care of an incapacitated person can increase the risk of depression.
- Isolation – living with no social contacts, no family and friends increases the risk in most people.
- Illness – if a person develops a chronic or life-threatening illness, such as heart disease, auto-immunity disease or cancer, there is a higher risk of developing depression.
- Personality traits – Some people with low self-esteem or who are excessively self-critical may be more vulnerable to depression. Personality traits are related to genetic inheritance as well as education and social environment.
- Family history – if any of your first-grade relatives have already suffered from depression the likelihood that you will is higher.
- Previous personal history – if a person has already had a previous episode of depression, the risk for recurrence is increased. The more episodes a person has experience in the past, the greater the risk of developing further depressive episodes in the future.
- Pregnancy, birth, menses and menopause – women are more vulnerable to depression than men and evidence points to different hormonal environments. Hormonal imbalance and variability cause higher risk in women’s different life phases. A well-known example is postnatal depression.
- Alcohol and drugs abuse – People tend to use drugs to produce altered states of mind and also as a kind of self-medication. In certain cultures, depressed men are particularly prone to abusing alcohol. The toxic alcohol effects can lead to a spiral of depression.
Also, the use of cannabis to aid relaxation can result in depression, especially in teenagers.
- Sleep and vigilance pattern – we have seen that, while distressed people can have trouble sleeping well, sleeping disorders such as insomnia, hypersomnolence (sleeping too much) or waking too early are common depression symptoms. Nevertheless, if you have a poor bedtime habits with long-lasting insomnia due to excess work or leisure, this will increase the risk of depression in many cases because of physical exhaustion and bodily imbalance. Sleep is essential for physical health and neglecting it can lead to unhealthy outcomes.
Another typical example is the one of snorers in which breathing is shortly paused during the night. This wakes them up very briefly without having conscious memory the next day. But their sleep is interrupted and is not restful. The consequences are tiredness and exhaustion during the day, which can cause depression in the long term. It is clear that depression and sleeping disorder often occur together and aggravate each other.