1) Is There a Biological Cause For Depression?:
With about 350 million people affected worldwide, or about 5% of the world’s population, Depression is a pretty widespread problem.
-Especially given its increased-concentration in 1st world countries (~7%).
Only Anxiety occurs in larger numbers (~18%).
But, what exactly going on inside people with these disorders?
Is it just cognitive-distortions & chemistry, or is there an actual Biological basis for it?
Well in the above video, ASAPScience tries to find out…
2) Pure Chemistry Is Old Thinking:
So previously, scientists thought that depression came only from a chemical imbalance in the brain.
They believed there was a neurotransmitter deficiency involving a lack of serotonin, the so-called “Feel-good chemical”.
BUT! The only real evidence for this was studies that showed when some depressed people were given serotonin boosters, they felt better.
So, those researchers decided depression was a 1-cause, 1-brain-chemical problem.
And although chemical-imbalances are still probably involved, this view was unlikely to tell the whole story.
As the med-school professors saying goes, “Half of what we’re about to teach you is wrong. We just don’t know which half.”
3) More Recently: Brain Cell Growth & Connections Play Larger Role:
Recent scan-based studies show compelling discoveries about the structure of depressed brains.
The most notable one is that the Hippocampus region tends to be much smaller than average.
There is also a good chance that at-least 5 other areas are physically affected, too.
But the interesting characteristic of the HC, is that it controls most of memory & a good chunk of Emotion.
And most-shockingly, the longer a person is depressed, the smaller the hippocampus becomes.
4) Stress Shrinks The Hippocampus, Increases Mood-Disorders:
Both the cells that comprise it, & the networks they form also deteriorate.
Our old nemesis, Stress is a big culprit in this bizarre decrease of neurons.
Get Dr. Amen to scan that one!
But hope is not lost! Other studies show that when this region is regenerated, including new neurons, mood improves!
So in other words, if you are under the type of stress that is toxic (ie: high, chronic, irrational, non-negotiable, as opposed to the low-medium, positive-challenge type),
That environment is -literally- destroying your hippocampus & making you depressed at the physical level.
5) Happy-Accident, You Can Regrow Your Hippocampus!:
Weirdly enough it turns out many modern drugs, including serotonin-boosters, have an indirect effect that causes brain-cell growth!
And this is actually the real reason why these drugs seem to help.
Experimentation produced a success, just not for the original reasons they thought.
These drugs may help directly, and also end-up triggering the release of different brain-chemicals that encourage and protect neurogenesis.
Most notably, this is exactly the mechanism believed to be working behind the drug Prozac, which is still not completely understood.
And because of these study-findings, science is starting to shift its focus to drugs that more directly promote neurogenesis.
Good-bye, excess body-weight and completely-flat emotions! Hello Brain POWAH!
6) More Than Just Physical, What About Your Personal Code?:
Although the hippocampus-shrinkage is the the most glaring direct issue we know of right now,
Many Genetic factors have been discovered as-well!
One landmark study found that variations in something called The [Serotonin] Transporter Gene (no relation to Jason Statham),
Can leave people with mutations increasingly-vulnerable to depression.
Each of us has 2 copies of this gene.
But there are 2 variants: Short and Long.
And you can end up with any of the possible combinations: 2 long ones, 1 long & 1 short, or 2 short ones.
7) The Transporter Gene Controls Emotional Resilience:
But as the study revealed, mutants matter.
33% of people with 1 short STG became depressed after stressful life events.
People with 2 short STGs did much worse.
People who had 2 long copies were much less likely to get sad & stay that way after the same type of emotional stimulus.
As you might expect, the results aren’t just confined to studies.
As a trend, the people with 2 short copies of this gene have the highest incidence of depression.
8) More Genes, More Problems?:
Many other genes besides The Transporter have been implicated in depression.
And that would tend to make sense, as depression and bipolar disorder both tend to run in families.
Even for people with schizophrenia, their chance of getting it increased by 10x if they had a first-order relative with the disorder.
In a rare identical twins study, if 1 twin had BPD, the other had between a 60-80% chance of having the same disorder.
9) Still Further-Afield:
The list of other possible causes is still pretty long.
Things like Sleep, Environmental-Impacts, Gut Microbes, Food & Drink contamination, Inflammation, and even Allergies, are all possibilities in creating a direct-effect or an indirect-cascade that can result in depression.
Even considering all the work that’s been done, science has just scratched the surface in the hunt for a cure.
And those cures can’t come soon enough, because it will probably turn out that anxiety & depression is not a weakness of character, but simply a genetic deck stacked against a blameless individual.
(until that day, get out there & run like hell!)
Check out the details at the Links:
JUMP BONUS! The School Of Life To Not Take Faulty Machinery Too Seriously:
Video 1 by YT-ASAPScience
Video 2 by YT-The School Of Life
Photo, “sad cat diary” by Flickr user Greyloch
• HarvardHealth-What Causes Depression?
• More Coverage: HT-Inflammation & Depression | HT-Exercise Generates New Brain Cells In Hippocampus
• Source Study: NeuroPsyPharm-Serotonin and hippocampal neurogenesis