We are truly intricate and complex — a biological system — and genetic variants often don’t have a huge impact on their own. Instead, the impact comes in the combination of gene variants or the interaction of a variant with the environment (toxins, stress, sleep, diet, pathogens, etc.).
A brain imaging study recently showed that the combination of a BDNF genetic variant plus a serotonin receptor variant literally changes the brain. Instead of just looking at a single genetic variant, this article digs into how the combination of these two variants interact to increase the risk of depression, anxiety, and bipolar disorder.
Let’s get into some background science and then go into how BDNF and serotonin work together.
Background on BDNF:
You may think you only have the brain cells you were born with. Perhaps your parents told you this when you were a teenager to prevent you from drinking :-)
However, research now shows that you can actually add brain cells to certain areas of your brain, especially in the hippocampus. You can also increase the connections between the neurons, increasing the brain’s plasticity.
BDNF is the key to producing more neurons.
BDNF stands for brain-derived neurotrophic factor. It is a type of protein called neurotrophin. BDNF works in several ways:
- BDNF encourages new neuronal growth from stem cells
- it protects neurons from injury and cell death
- it improves neuronal function (important in learning and mood)
To improve the way the neurons function, BDNF binds to receptors that are located in the synapses between neurons. BDNF potentiates or increases the signal from one neuron to the next.
In addition to being found in the brain, BDNF is also found in the peripheral nervous system – helping muscle nerves to function well. This connection with muscles is one way that exercise increases BDNF.
Studies on BDNF show:
- Chronic stress causes a decrease in BDNF.[ref]
- Low BDNF is linked to Alzheimer’s disease[ref] and Parkinson’s[ref][ref]
- People with depression usually have lower levels of BDNF.[ref][ref][ref]
- Mothers with postpartum or during-pregnancy depression have low BDNF[ref], and the elderly with depression also have low BDNF.[ref]
- Low BDNF is linked to obesity.[ref]
BDNF doesn’t necessarily act alone in causing diseases. It often interacts with neurotransmitters or cytokines. For example, a recent study found that in people with schizophrenia, lower BDNF levels correlated with higher IL-2 (interleukin-2) levels. IL-2 is an inflammatory cytokine that is part of the immune system.[ref]
BDNF Genotype Report:
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Lifehacks:
There are several different ways that you can increase your BDNF levels:
Lifestyle changes for improving BDNF levels:
Sleep: Good quality sleep boost BDNF. Sleep is the mediator between stress and BDNF levels.[ref] Make sure that you don’t have light in your room at night when you sleep. Dim light at night decreases BDFN levels (animal study).[ref] Be sure to read this article: Blue-blocking glasses.
Sunlight: Exposure to sunlight or bright light during the day increases BDNF levels.[ref] Go outside! Or take a vacation to a sunny area.
Avoid Chronic Stress: Stress decreases BDNF levels.[ref] We all know that stress isn’t good for us, so here is one more reason why you should avoid it. While easier said than done, there are tried and true methods for reducing stress, including exercising (go for a walk in the sunshine!) and sleeping well.
Exercise has been shown in multiple studies to increase BDNF levels reliably. It is thought that this is one way that exercise decreases depression for some people.[ref] Specifically, aerobic activity or endurance-type exercises are best for increasing BDNF.[ref]
Supplements for increasing BDNF:
Related Articles and Topics:
Bipolar disorder and the circadian clock genes:
New research shows that depression and bipolar disorder are linked to changes or disruptions in circadian genes. Some people carry genetic variants in the circadian genes that make them more susceptible to circadian disruption.
Tryptophan:
Tryptophan is an amino acid that the body uses to make serotonin and melatonin. Genetic variants can impact the amount of tryptophan that is used for serotonin. This can influence mood, sleep, neurotransmitters, and immune response.
Circadian Rhythm Genes: Mood Disorders
Circadian rhythm disruption can drive mood disorders. Learn more about the genes involved and the ways to normalize your circadian rhythm.
Anxiety: Genetics and personalized solutions
This article covers genetic variants related to anxiety disorders. Genetic variants combine with environmental factors (nutrition, sleep, relationships, etc.) when it comes to anxiety. There is not a single “anxiety gene”. Instead, there are many genes that can be involved – and many genetic pathways to target for solutions.
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