Biological Evidence for Depression - Mental Illness Exists
Common messages spread by certain special interest groups are that “mental illness doesn’t exist” and “there is no biological evidence for mental illness.” It’s not surprising I take great exception with these claims. So do most doctors.
But the brain is an extremely complex organ and refuting the above notions is hard. It’s not a two-word response. So, I’m going to attempt to give a two-part overview, in plain English, of some of the research around the biology of major depressive disorder according to a meta-analysis done in 2010 (see below).
There are several promising areas in the research of the “pathophysiology” (the physical changes stemming from a disease) of major depressive disorder (MDD), all with strengths and weaknesses.
Depression, Genes, and Stress
Studies consistently show genetic factors affect 30% - 40% of cases of MDD. The other 60% - 70% of cases are closely linked to stressors both in the present and in childhood. A wide array of genes have been found to be associated with MDD.
[Note: the Mayo Clinic now offers a gene test to assess how your body would react to particular antidepressants.]
Depression and Stress Hormones
Elevated levels of cortisol (a stress hormone) are associated with times of stress. Cortisol levels typically decrease to normal levels once the stress has passed, however, in depressed patients, cortisol levels appear to be permanently elevated. Elevated cortisol is more prominent in those with childhood trauma.
[Note: cortisol levels have been linked to other mental illnesses such as anxiety and PTSD as well.]
Cortisol can be measured in saliva and elevated cortisol levels are almost exclusively found in patients with severe and psychotic depression. The corticotropin-releasing hormone (which stimulates cortisol release, among other things) has been repeatedly shown to play a major role in depression (and other diseases).
Serotonin, Dopamine, and Noradrenaline (Monoamines)
Monoamines like serotonin, dopamine and noradrenaline have been widely studied and almost everything that increases the concentration of monoamines has been shown to have antidepressant effects.
While reduced central serotonin has been associated with “mood congruent memory bias, altered reward-related behaviors, and disruption of inhibitory affective processing,” testing of serotonin levels in people with MDD shows inconsistent results.
Research is increasingly showing the role of dopamine in MDD. Dopamine levels are consistently low in depressed patients and experimentally reducing dopamine levels is associated with an inability to feel pleasure and decreased performance on a reward-driven task in those with an increased risk of depression.
It is thought the monoamine effects seen are likely downstream effects of the primary abnormality, which is unknown. New drugs that affect dopamine appear to have promising antidepressant uses, particularly in hard-to-treat depression.
[Note: some dopamine altering drugs are on the market but are often not covered for mood disorders due to lack of FDA-approval in those disorders.]
Neuroimaging of Depression
Because of the cost of neuroimaging studies, only small-scale study data is available and most studies don’t have overlapping results due to subjects and neuroimaging methods selected.
However, structural abnormalities and decreased brain volumes have consistently been found in several areas of the brain of those with MDD. Brain volume in those with untreated depression decreases with the length of the depression.
Biological Evidence for Depression - Part Two Next Week
Next week I will discuss the three remaining biological depression areas of research and bring together what this information means.
Notes on Information Source
This information is a concise synopsis of “Pathophysiology of Depression: Do We Have Any Solid Evidence of Interest to Clinicians?” by Gregor Hasler at the Psychiatric University Hospital, University of Berne, Switzerland. Published: World Psychiatry. 2010 October; 9(3): 155–161.
Yes, I have massively condensed this article and explained it in plain English, so for all the details, refer directly to the article.
Comments are welcomed as always; however, please be aware comment moderation has become stricter. Comments that are not on topic or that disparage others will not be allowed. Thank-you for your cooperation
Tracy, N. (2011, April 7). Biological Evidence for Depression - Mental Illness Exists, HealthyPlace. Retrieved on 2019, July 21 from https://www.healthyplace.com/blogs/breakingbipolar/2011/04/biological-evidence-for-depression-mental-illness-exists
Author: Natasha Tracy
The problem with meta-analysis is that they rely on studies already carried out which themselves have inherent flaws and biases. The major flaw being being confirmation bias (you see what you want to see and downplay contradictions ) and that correlation is not causation. Our mental states influence our physiology, long term exposure to stressful environments causes adverse affects and changes on our physiology. That physiological changes are evident in some subjects and not others does not imply causation.
Presenting selectively chosen phrases from a single meta-analysis without presenting any qualification for the points you are making is misleading and potentially harmful. The truth is that the evidence shows (and is stated repeatedly in the study) that no single varifiable biomedical abnormality can be proven to cause depression.
There is a huge body of evidence, not just from special interest groups but from within the psychiatric field itself and from clinical psychologists and therapeutic practitioners, not to mention experiences of 'service users' that shows that treating mental distress as biological illness is unfounded and potentially very harmful.
If the purpose of your site is to support and inform sufferers of mental distress you have a responsibility to present informed unbiased information. Statements such as "biological evidence for depression - mental illness exists" are misleading and supported by the paper you are quoting
Given that the scientific understanding of these issues is likely to beyond most readers of your article it is likely to simply cause more distress and alienation.
Some children seem to be born with mental illness, how do you explain that? And some with very loving families
I agree, however, at times trauma play a part in mental illness and there is even one illness PTSD where trauma is a 'criteria'
If there is no "biological basis" for mental illness just because there is no biological test discovered YET to accurately diagnose it doesn't necessarily mean no biological basis exists, anymore than you could argue the world is truly round when it was once believed to be flat.
Why do you think antipsychotics help schizophrenics. Do you honestly believe their psychosis would disappear or be alleviated on it's own without ongoing help?
MEDICATION helps treat BIOLOGICAL illnesses
Genetics have a biological basis. I am adopted and did not grow up with my biological family but I do know mental illness runs in my BIOLOGICAL family
I am bipolar and have been involuntarily commited before because I was suffering from psychosis brought on by untreated mania . When I was given antpsychotics I was CURED of the psychosis and the mania was brought under control. Other meds help keep it under control and improve my quality of life and reduce the kindling effect
Depression has often been referred to the common cold of mental illness. There is a biological basis for colds too but some would say there is no real cure, ok well maybe there are some medications that will help alleviate the symptoms until you get over it but unlike some mental illnesses you don't just get over it. They don't just disappear on their own and people need medication on a daily basis to cope.
If there is a biological basis for some illnesses such as with cancer then why does treatment not help everyone. BECAUSE THEY HAVEN'T FOUND A CURE, just like some forms of mental illness
Granted people die of suicide in large part by choice but their depression is not a choice. No one wants to be unhappy. CBT, positive thinking and psychologists can only do so much to help.
You could also argue that cancer is a choice to some degree and in some cases. What I'm talking about is cigarette smoking. There a reason there's a warning on cigarette packages
No doubt certain behaviours can lead to biological illnesses
Show us real evidence instead of relying on muddled thinking, unclear results and meaningless correlation. If your claim of clear differentation between depressed and non-depressed people would hold water don't you think doctors would be diagnosing these individuals with MRI-scans instead of questionairs? The day mental illnesses become objectively diagnosable and effectively treatable is the day psychiatry will cease to be since neurology will simply take over.
Meditation has been shown to increase feelings of happiness and contentment with a physical correlate in the brain but that doesn't mean meditation is a treatment for a medical illness, is it? Unless you consider the suffering inherent to life as stemming from mental illness of course but then we are all mentally ill just like christianity considers the whole of humanity sinners.
In your line of reasoning the fact that certain chemicals have an effect on the brain and its functioning apparantly translates to there being something physically wrong with it in the first place. If I drink ethanol and it elevates my mood apparantly there must have been a problem with my brain which was fixed by the self-administered cure in the form of liquid happiness. The only thing that proves is that the mind and the brain aren't seperate entities and subjective experience and brain chemistry mutually influence each other.
The argument that neurotransmitters have 'antidepressant' qualities has grown rather stale: clearly they regulate mood to a certain extent but little is known about them and medication which aims to elevate the levels of serotonine etcetera do not have a statistically significant effect on happiness, at least not without taking into account the placebo-effect as shown by double blind studies. Basically a whole industry is growing rich by selling people chemicals that do not 'heal' anything and rely on belief in order to produce measurable effects.
A correlation between stress, cortisol and feelings of unhappiness doesn't prove in any way your thesis of objectively verifiable conditions known as mental illnesses. No-one doubts that suffering exists, nor that it can be both physical and mental.
Perhaps in your next post you could try to explain why psychiatry is not a form of (secular) religion because to me it clearly is. In lieu of undeniable evidence (obtained in the same way cancer and other illnesses are diagnosed: through lab results) which you clearly failed to provide it all boils down to belief. Do I want to believe or not? If you find it easier to cope with life's problems (which for some are clearly more difficult to bear than for others) by accepting this belief fine but then at least be intellectually honest enough to admit your position relies solely on pragmatism. If you want to use drugs in order to cope fine and they might have positive effects on mood and behaviour but do not claim they fix anything or constitute proof of a physical problem.
PS: "So do most doctors" is not a valid argument (a position is not true because it is held by many people even if they have university degrees in the field, it is true or untrue based on the facts), do you have sources to back up the claim that GP's and specialists outside of psychiatry actually subscribe to this view?
What sites or books did you use for your research or what would you recommend?
Thanks a lot! The information on your blog is also very helpful :)
Seriously, though, when I was at a major university, the math dept. offered free statistics help and nobody in medical research took advantage of it. The math dept. offered this help because they found the medical study designs and analysis to be extremely flawed. It serves no one but big pharma (or whomever else seeks to profit) when deeply flawed research is done.
I don't understand why those who think mental illness has mostly biological causes think that those of a different opinion are denying their suffering and struggles. Most do not deny that there is terrible suffering.
The truth is, people who do research in the physical sciences and mathematics laugh at the medical researchers with their lousy studies and poor knowledge of statistics. The fact the research is horribly done is no reflection upon the people who are suffering (including myself). I don't know why it gives people comfort to think that they have a defective brain, that they genetically inherited, rather than some other cause. I don't know what the cause is. NOBODY knows.
I think a lot of people want to believe there is a biological and genetic basis so they can point to some scientific reason to feel less responsible for their troubles. Therefore, when others deny a biological cause, it feels like an attack on their character, when it was not usually meant that way.
Even though many psychiatrists say that bipolar disorder is caused by genetics and changes in the brain, the evidence for that is terrible! Patients shouldn't be taught this stuff as fact, because nobody knows what the causes are. We do not know for a fact that any mental illness is caused by some physical defect in the brain. That's the reason the mental illnesses are shunted to psychiatry. Otherwise, the neurologists would take over.
Don't let confirmation bias keep you from reading and absorbing studies that contradict what you may want to believe. This idea of a biological basis is FAR from settled. If bipolar was so darned genetic, the genes would have been found by now. Maybe there are 10 different causes of bipolar, or 100, or maybe it's not genetic after all. Maybe it is an epigenetic illness. I really don't know. That doesn't make my depression problems fake. And I don't think anyone would be posting on this blog if their problems were fake. It is a mistake to be too sure of your facts, when they aren't really facts at all.
If you feel more comfortable NOT being mentally ill and decided that your physical symptoms were the cause of your mental symptoms, well, that is up to you. But why deny the suffering of others just because you have denied your own? You don't know what their personal, medical and hormonal profiles are. You have extrapolated a bit too far on very little data.
Despite all that you have mentioned, I do not believe mental illness exists. I was diagnosed with depression, anxiety and panic disorder. In the end, i found out that it was just hormonal imbalance that has cause the symptoms. Therefore, i did not have any mental illness after all. The psychotherapeutic drugs did not work even when they were switched from one to another. However, I do agree that cortisol helps balance with the adrenals in our body and prevents a burn-out. And that does not necessarily linked to "depression", as it is more of physical health. With that being said, there is no reason to rebuke the so called "common interest group" that voice out to say that there is no biological evidence for mental illness.
I believe that it is all about hormones, diet on the physical side and one's personal upbringing and the ability to take stress that causes the so called symptoms of mental illness which can be easily resolved by counseling or psychotherapy.
I could go on a long rant about Elpenor's close-minded comments, but instead I will just say this.
While the theory that people are trying to get out work by saying they're mentally ill is "interesting", I know for a fact that it's not true for most of us. How would you explain getting accepted into a prestigious school, interning at the job of your dreams, doing great, loving life, only to find your chemicals have gone unbalanced again and you're forced to put your dreams on hold to be stuck in bed every day? Bipolar doesn't care if your life is going well or not.
I think I speak for most of the bipolar community when I say that one of the worst things about being mentally ill is most of the people who don't have it don't understand it.
I wouldn't wish it on anyone.
historical facts can remind us that the treatment of people with these illnesses, throughout time, has been guessing, if anything at all. Depending on their own history, their education about their illness, plus how they are feeling at the time, comments that are made by folks who are stuck on one idea, or opinion about this topic. It's obvious that this is an emerging area of understanding, much further behind that what is known about any other part of the body & that
Wow sound just like the excuses I hear from the alternative health woo-woo doctors as to why they have no biological evidence to support what is unfounded opinion. There is no rational hypothesis for any mental illness having a biological basis, and until Psychiatry can prove beyond doubt that this is biological then medicine should stick to physical illness. The truth is the only evince you have is qualitative and the vast majority of this is funded directly or indirectly by the pharmaceutical industry.
This is typical of the type of simplistic nonsense we hear of biopsychiatry zealots, you misrepresent my point by suggesting I do not wish to get out of bed and work, an obvious judgement on your part. If I spend 9 years in training and studying at own expense for a profession and the government decides to cut my job in order to bail out criminal financial agencies, why should I then be expected to work flipping burgers in fast food restaurant? How about if you find yourself in a position where the only means available to feed your family were to sell your body to rich businessmen, how would you feel about that, would you get out of bed for that, or would you lie there in a depression? Yet these are the choices faced by many in our neoliberal anti human societies, where job opportunities for a large section of the population are declining year on year as corporate profits increase. These people are victims of our society but rather helping them in any practical sense the medical industry supported by government labels and drugs them. Medical models for mental illness totally eliminate the social causes, allowing government and society avoid its responsibility.
"Trauma doesn’t equal mental illness."
No but it can lead to it if repressed, trauma can eat away at an individual , leading to depression, alcoholism and drug addiction, where allowed to fester. Speak to any combat veteran who returns from a war totally dehumanised or a victim of rape or abuse, who do these people turn for support in order to heal their emotional wounds, a psychiatrist?
"If you would rather have a dead brother, or mother, or friend, than a medicated one, well, again, that’s your business, but mot people wouldn’t make that choice."
Actually most normal human beings would rather a happy unmedicated family member than a family member so unhappy in their lives that the only thing preventing them from killing themselves are prescription drugs, They would support and empower their family member helping them to get positive recovery focused counselling or psychotherapy. Also many mental health issues have their origins in the family bullying, abuse, religious or social coercion etc, so here again biopsychiatry becomes another way of disempowering the victim to protect the abuser by suggesting the victim suffers from a mental disease.
Biopsychiatry is a unquestionably a construct of the pharmaceutical industry, who pump money into research departments, to generate academic cheerleaders for their cause, the profit motive. Individuals such as yourself should be aware of the damage you do by proselytising for them.
You are certainly welcome to that opinion. If you do not wish to get out of bed and get a job, that's your business, but it seems like you would be homeless fairly quickly. If you don't have a problem with that, then that's up to you.
Some people have trauma in their background and have a mental illness, some do not. Some people do not have a trauma and do not have a mental illness, some do. People are unique. Trauma doesn't equal mental illness. Many people with a mental illness work very hard at dealing with whatever their particular life experiences have been, that doesn't necessarily make a mental illness disappear.
Well, if you would rather lose an ear and paint, well again, that's up to you, but I rather like my ears. Keeping my ears isn't about "society" or "convention" it's about the fact that I want my ears. And arms. And pretty much everything else I was born with.
And for all the people who committed suicide, that isn't about "fitting in" either, it's about saving their lives. If you would rather have a dead brother, or mother, or friend, than a medicated one, well, again, that's your business, but mot people wouldn't make that choice.
I wrote that mental illness is only a problem when it causes problems in your life. http://www.healthyplace.com/blogs/breakingbipolar/2011/03/mental-illness-is-only-a-problem-when-mental-illness-is-a-problem/
As for genes even if in Van Goghs case if they were to identify the set of genes that made him stand out from the norms what would that gene be, a biopolar gene or a gene for artistic creativity? What then? Give someone like van Gogh a drug that switches off the respective bipolar/creative genes so he can be like everyone else and spent his life working 9-5 as an office clerk.
Thanks so much for this article! I have always wondered if cortisol levels were elevated in patients with depression. I have OCD and Bipolar and wondered why I always felt stressed. I guess that explains it!
I think you're missing my point.
While yes, I'm the kind of person that finds research interesting, it's not terribly useful to me. If it doesn't help me personally get better, it's of limited personal value.
This information is less for me than it is for every person with a mental illness who has to stand up to people saying mental illness isn't real. It doesn't exist. Mental illness is just "normal emotion." And so on.
Legally, mental illness is already an illness, legality has nothing to do with it. What it has to do with is dispelling myths. Brain scans don't change my life one whit.
That's the idea. Glad you found it helpful.
Thank you for the update. I can respect your enthusiasm with the theories. If lack of mental heath or stability is proven biologically it is a brave new world indeed. However, I am on the other side of the aisle on this. I will rant and muse now on these things. What would change if a bipolar disease gene was actually discovered?
Would medical, legal, and political laws change? How so? To what degree? Would civil and religious authorities be more merciful to diseased offenders and as a consequence less so to their healthy victims? By what percentage? Who would decide?
What new tests would apply? What old tests would be validated? "Maybe he/she is just an undiagnosed or untreated bipolar?" Would a cruel act by someone with a mental disease diagnosis now be less cruel? Would a kind or courageous act be even more kind or courageous? Would a contract signed by someone with mental disease now possibly be less legal?
Would having such a gene make one less mature or less responsible or excuse poor hygiene or table manners or bad debts or social graces or watering flowers or patience with children? Maybe a lack of confidence or excessive pride is just due to a bipolar disease gene. Is there a gene marker for that? A graded difficulty factor? How about with exercise or volunteering or vitamins figured in?
What test can currently be applied to prove conclusively someone has a bipolar disease? Would the test hold up in a bar room discussion or in a court of law? Are unhappy or abusive or abused people less stable generally and more rude more often than happy people simply because of a gene?
Does a bipolar disease gene possibly contribute to make you sad or angry or greedy or jealous? Does another gene than make you joyful or loving or kind?. Does another one make you a quitter or lazy or fat? More apt to make impulsive choices with unhappy consequences? Is it a question of personal behavior or of social conduct or is it mainly biology? Is there a "scientific cure" for the way some people relate to or respect others or themselves? Could a medical drug or a surgery fix this. If so, prescribe me one please.
Thanks for this article. Lot's of insights, resources, links and the like that dispel the myths of depression as something that's "all in the mind", tantamount to eliciting preconceived (and erroneous) notions from people about how "easy" it may be to handle.
Yes, the article references 88 other publications. It's a pretty good overview of where mental illness is right now. We're far from knowing enough, but we do know some things.
Now that you show that there is "Real" science from "Real Institutions" the anti psych crowd can only go personal. Science removes their argument so like a child they get personal. Keep fighting them with science, shine a light into their empty theories.