Reserpine, an indole alkaloid, was extracted from Rauwolfia serpentina or Indian snakeroot. It has been in used in Indian medicine for several hundred years, and was a treatment for conditions that we might now recognise as mental illness. Gandhi is alleged to have taken it as a relaxant.
It showed antipsychotic effects and was used in the treatment of high blood pressure. It has subsequently been banned from use in the United Kingdom, because of severe, problematic side effects. These included severe depression and unexpected suicide.
One of its predominant effects on the brain was to deplete stores of monoamine neurotransmitters, such as adrenaline, noradrenaline, and dopamine.
This is one of the bits of evidence that lead to the formulation of what was to become known as the “monoamine theory” of depression, a theory that still holds a lot of influence up to the present day.
The current focus has been on Serotonin, another monoamine neurotransmitter in the brain.
Much of the money that has been spent on research into depression has come from the pharmaceutical industry. The search for a “magic bullet” to cure physical illnesses that started in the 1950s, was also applied to the search for effective psychiatric medication. This still continues to this day, and althougth the idea of a pill to cure every ill is not as strong as it once was, the search still seems to be unconsciously driven by this idea.
It is therefore not surprising that much research has been focussed on the neurochemistry of the condition called depression The intent has been to find drugs that alter both the levels, and the balance, between various neuro-transmitter chemicals in different parts of the brain. The research evidence has supported the idea that brain areas that use serotonin as a neurotransmitter, have a particular role to play in the control of our emotional states.
It is believed that these chemical neurotransmitters have a clear role both in the pathogenesis, and in the symptomatic presentation of depression.
Such studies have also looked at those who are at risk of developing depression, as well as at those patients who have become suicidal while taking a Selective Serotonin Reuptake Inhibitor, as many of the modern anti-depressant drugs are known.
The existence of an association between depressed mood and low brain serotonin levels has been overinterpreted, and there is a strong and prevalent belief that it is these low levels of serotonin that cause the depression. From my reading of the research literature I remain unconvinced of this.
Association is not proof of causation, and the reality could be that the relationship works the other way round and the low serotonin levels are a result of the depression. The jury should perhaps return the Scot’s legal verdict of Not Proven with respect to this theory.
Many of the young people that I met have been told by their doctors or psychiatrists that their problems are due to a chemical imbalance and additionally, have been informed that they need medication to cure this “disease”.
Medication has only been shown to be helpful in those with have severe depression – they form the minority of those who present with depression, and although these drugs can be helpful for many they do have marked side effects, including suicidal thinking and emotional blunting.
Depression appears to be a “final common pathway”.
Many different causes come together, and their interaction leads to a depressed mood as a common symptom. In other words, making a diagnosis of depression is on a par with making a diagnosis of chest pain, where it describes a symptom, or possibly cancer, of which there are many varieties with differrent treatments and outcomes.
Several different neurotransmitters are involved in the brain’s control of our mood and emotions, as is the plasticity of the central nervous system, and the interactions between the biological brain and the many social and psychological stressors found in our environment.
Diet, lifestyle and the increasing stresses of living a twenty-first century life contribute to a significant degree.
More recently there has been an increase in interest about non pharmacological strategies that can be used either in an attempt to prevent depression from arising in the first place, or as a way of inoculating susceptible individuals to the triggers. There is also interest in developing treatments that can be used as an early intervention as soon as the first signs of depression appear, in order to get a very rapid response and so minimise the secondary harm that depression causes.
Prevention is seen as being a far better option than a cure.
Serotonin may not be the “cause” of depression but it does have widespread actions in the brain and body. In the brain these actions are involved in the day to day fluctuations and control of our mood and behaviours. The pathways involved seem to contribute to our sense of well-being, one of the things that supports both happiness and mental health, with knock on benefits for our physical health and contribute to our longevity.
Their impact has much to do with ensuring that we can go on and have an enjoyable and healthier old age.
Negative mental states have a similar, but negative effect on our lives.
It would seem sensible to do what we can to maintain ourselves in as healthy a condition as possible, and keeping our serotonin levels within normal limits would appear to be one of the things that would make a useful addition to our health care regimen.
Areas influenced by Serotonin.
- Mood and emotions.
- Cravings – especially for carbohydrates. This craving can be a secondary symptom of depression.
- Self esteem.
- Suicidal ideation.
- Obsessive Compulsive Disorder.
- Irritable bowel syndrome.
- Possibly plays a role in Bulimia.
- Pain threshold and pain tolerance.
- Sleep regulation.
- Body temperature regulation.
So what can we do to influence our serotonin levels without recourse to medication?
1. Lighten our darkness.
In the past the human race has spent a great deal more of its time outdoors, in natural daylight. Even in the middle of a European winter the intensity of the daylight is about a thousand times brighter than artificial light. In the summer this difference is even greater.
Our modern lives are lived indoors to a greater degree than ever before, with most light coming from flourescent tubes or lightbulbs that do not produce a full spectrum of light.
Blue light, between 460 and 480 nanometre wavelength, inhibits the productin of Melatonin by the pineal gland. Melatonin is the hormone that tells us it is time to go to sleep, it is made from serotonin.
If the light intensity is too low, we will make melatonin during the day as well as at night, and this contributes to both lethargy, depression and fatigue during the day. The disordered sleep seen in some depressed patients may be due to this.
This lack of light of a suitable intensity may be one of the factors that has contributed to the rising incidence of depressive disorders over the last two hundred years or so.
So we should get outside as often as we can, perhaps by taking an early morning walk or sitting outside and eating lunch in the open air whenever we can.
2. Change our diet.
Omega 3 fatty acids have received a lot of hype over the last twenty years, and have been recommended for many conditions including ADHD, arthritis, anxiety and depression.
Much of our modern diet is very high in Omega 6 fatty acids. We get these from eating food that contains large amounts of grains or animals that are fed on grains. They are said to be inflammatory in nature, contributing to the production of inflammatory chemicals in the body.
There has been at least one study showing that those of us who eat a diet high in junk food, tend to be 40% more depressed than those who do not.
Omega 3 fatty acids come from sources such as seafood, vegetables and grass fed meat. They are said to be anti-inflammatory in nature.
There are studies that support their benefits in many modern health problems such as diabetes, high cholesterol, metabolic syndrome, dementia and depression. All of which it is thought, might be related to chronic inflammatory responses in the body.
A diet higher in these “good” fatty acids may contribute to higher serotonin levels and has many other health gains.
Dark chocolate that is at least 70% cocoa solids, also shows some promise in raising serotonin levels (which is my excuse for eating it!).
Excessive caffeine ingestion, in either hot or cold drinks, helps to deplete our brain of serotonin. Smaller amounts may have positive effects on alertness.
Choosing to modify our diet may help and will certainly have general health benefits.
Regular exercise that is within our usual comfort zone, also contributes to better mental helath and wellbeing. This is because being physically fitter help us to feel mentally fitter and also because of a direct effect on the levels of Tryptophan in the body. Tryptophan is a precursor chemical for the production of serotonin.
A sensible level of exercise would be about 30 minutes at a brisk walking pace or equivalent, at least three to four times a week.
Other physical treatments such as massage may also be of help
4. Lifestyle adjustments.
Changes we make that reduce our daily levels of stress are very helpful in maintaining our serotonin levels. This involves monitoring what we allow into our environment.
Drugs and alcohol have known mood altering abilities, but only make things worse if used to excess or inappropriately.
Some of the more popular recreational drugs of abuse can deplete our neurotransmitter stores making our mood and ability to function worse.
Changing how we think both about ourselves and the events in our world can significantly affect our mood and help us to maintain a stable mind state.
Taking care not to overwork, and to ensure that we get adequate relaxation time and sleep will also be sensible.
Mindfulness meditation has demonstrable benefits on brain chemistry and the connections between the parts of the brain that trigger strong emotions and those that we use to pay attention to what is going on.
This helps us to concentrate on happier experiences rather than the small things that might have gone wrong, as well as becoming more aware of our own responses to our thoughts, emotions and events.
Such responses are often based in the beliefs we have picked up about ourselves and the world as we have developed.
Certainly there is evidence to suggest that people who suffer with a severe major depressive disorder will benefit from medication. However the research also shows that the effects of such treatments are additive to other interventions such as cognitive behavioural therapy.
Those with mild or moderate major depression show little benefit from anti depressant tablets and we need to find alternative, effective intervention to help these groups.
Taking steps to manage our own brain chemistry may be an area for further research.
Taking a preventative stance in our own lives and going with the best current evidence would seem to be one way that we can contribute to our own mental health.
If you are taking medication do not stop without consulting your health care provider.
More recent research has cast some doubt as to the relationship between depression and serotonin, or at least the action of medication on serotonin receptors. It will be interesting to see what additional research has to add to this topic.