We looked at genetic clues to depression in more than 14,000 people. What we found may surprise you

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The core experiences of depression – changes in energy, activity, thinking and mood – have been described for more than 10,000 years. The word “depression” has been used for about 350 years.

Given this long history, it may surprise you that experts don’t agree about what depression is, how to define it or what causes it.

But many experts do agree that depression is not one thing. It’s a large family of illnesses with different causes and mechanisms. This makes choosing the best treatment for each person challenging.

Reactive vs endogenous depression

One strategy is to search for sub-types of depression and see whether they might do better with different kinds of treatments. One example is contrasting “reactive” depression with “endogenous” depression.

Reactive depression (also thought of as social or psychological depression) is presented as being triggered by exposure to stressful life events. These might be being assaulted or losing a loved one – an understandable reaction to an outside trigger.

Endogenous depression (also thought of as biological or genetic depression) is proposed to be caused by something inside, such as genes or brain chemistry.

Many people working clinically in mental health accept this sub-typing. You might have read about this online.

But we think this approach is way too simple.

While stressful life events and genes may, individually, contribute to causing depression, they also interact to increase the risk of someone developing depression. And evidence shows that there is a genetic component to being exposed to stressors. Some genes affect things such as personality. Some affect how we interact with our environments.

What we did and what we found

Our team set out to look at the role of genes and stressors to see if classifying depression as reactive or endogenous was valid.

In the Australian Genetics of Depression Study, people with depression answered surveys about exposure to stressful life events. We analysed DNA from their saliva samples to calculate their genetic risk for mental disorders.

Our question was simple. Does genetic risk for depression, bipolar disorder, schizophrenia, ADHD, anxiety and neuroticism (a personality trait) influence people’s reported exposure to stressful life events?

Girl or teenager leaning against wall, hand across face, looking down
We looked at the genetic risk of mental illness to see how that was linked to stressful life events, such as childhood abuse and neglect. Kamira/Shutterstock

You may be wondering why we bothered calculating the genetic risk for mental disorders in people who already have depression. Every person has genetic variants linked to mental disorders. Some people have more, some less. Even people who already have depression might have a low genetic risk for it. These people may have developed their particular depression from some other constellation of causes.

We looked at the genetic risk of conditions other than depression for a couple of reasons. First, genetic variants linked to depression overlap with those linked to other mental disorders. Second, two people with depression may have completely different genetic variants. So we wanted to cast a wide net to look at a wider spectrum of genetic variants linked to mental disorders.

If reactive and endogenous depression sub-types are valid, we’d expect people with a lower genetic component to their depression (the reactive group) would report more stressful life events. And we’d expect those with a higher genetic component (the endogenous group) would report fewer stressful life events.

But after studying more than 14,000 people with depression we found the opposite.

We found people at higher genetic risk for depression, anxiety, ADHD or schizophrenia say they’ve been exposed to more stressors.

Assault with a weapon, sexual assault, accidents, legal and financial troubles, and childhood abuse and neglect, were all more common in people with a higher genetic risk of depression, anxiety, ADHD or schizophrenia.

These associations were not strongly influenced by people’s age, sex or relationships with family. We didn’t look at other factors that may influence these associations, such as socioeconomic status. We also relied on people’s memory of past events, which may not be accurate.

How do genes play a role?

Genetic risk for mental disorders changes people’s sensitivity to the environment.

Imagine two people, one with a high genetic risk for depression, one with a low risk. They both lose their jobs. The genetically vulnerable person experiences the job loss as a threat to their self-worth and social status. There is a sense of shame and despair. They can’t bring themselves to look for another job for fear of losing it too. For the other, the job loss feels less about them and more about the company. These two people internalise the event differently and remember it differently.

Genetic risk for mental disorders also might make it more likely people find themselves in environments where bad things happen. For example, a higher genetic risk for depression might affect self-worth, making people more likely to get into dysfunctional relationships which then go badly.

Middle aged man looking sad, leaning on sofa, staring into distance
If two people lose their jobs, one with a high genetic risk of depression the other at low risk, both will experience and remember the event differently. Inside Creative House/Shutterstock

What does our study mean for depression?

First, it confirms genes and environments are not independent. Genes influence the environments we end up in, and what then happens. Genes also influence how we react to those events.

Second, our study doesn’t support a distinction between reactive and endogenous depression. Genes and environments have a complex interplay. Most cases of depression are a mix of genetics, biology and stressors.

Third, people with depression who appear to have a stronger genetic component to their depression report their lives are punctuated by more serious stressors.

So clinically, people with higher genetic vulnerability might benefit from learning specific techniques to manage their stress. This might help some people reduce their chance of developing depression in the first place. It might also help some people with depression reduce their ongoing exposure to stressors.

If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14.

Jacob Crouse, Research Fellow in Youth Mental Health, Brain and Mind Centre, University of Sydney and Ian Hickie, Co-Director, Health and Policy, Brain and Mind Centre, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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  • See what other 10almonds subscribers are asking!

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    It’s Q&A Day at 10almonds!

    Q: I would be interested in learning more about collagen and especially collagen supplements/powders and of course if needed, what is the best collagen product to take. What is collagen? Why do we need to supplement the collagen in our body? Thank you PS love the information I am receiving in the news letters. Keep it up

    We’re glad you’re enjoying them! Your request prompted us to do our recent Research Review Monday main feature on collagen supplementation—we hope it helped, and if you’ve any more specific (or other) question, go ahead and let us know! We love questions and requests

    Q: Great article about the health risks of salt to organs other than the heart! Is pink Himalayan sea salt, the pink kind, healthier?

    Thank you! And, no, sorry. Any salt that is sodium chloride has the exact same effect because it’s chemically the same substance, even if impurities (however pretty) make it look different.

    If you want a lower-sodium salt, we recommend the kind that says “low sodium” or “reduced sodium” or similar. Check the ingredients, it’ll probably be sodium chloride cut with potassium chloride. Potassium chloride is not only not a source of sodium, but also, it’s a source of potassium, which (unlike sodium) most of us could stand to get a little more of.

    For your convenience: here’s an example on Amazon!

    Bonus: you can get a reduced sodium version of pink Himalayan salt too!

    Q: Can you let us know about more studies that have been done on statins? Are they really worth taking?

    That is a great question! We imagine it might have been our recent book recommendation that prompted it? It’s quite a broad question though, so we’ll do that as a main feature in the near future!

    Q: Is MSG healthier than salt in terms of sodium content or is it the same or worse?

    Great question, and for that matter, MSG itself is a great topic for another day. But your actual question, we can readily answer here and now:

    • Firstly, by “salt” we’re assuming from context that you mean sodium chloride.
    • Both salt and MSG do contain sodium. However…
    • MSG contains only about a third of the sodium that salt does, gram-for-gram.
    • It’s still wise to be mindful of it, though. Same with sodium in other ingredients!
    • Baking soda contains about twice as much sodium, gram for gram, as MSG.

    Wondering why this happens?

    Salt (sodium chloride, NaCl) is equal parts sodium and chlorine, by atom count, but sodium’s atomic mass is lower than chlorine’s, so 100g of salt contains only 39.34g of sodium.

    Baking soda (sodium bicarbonate, NaHCO₃) is one part sodium for one part hydrogen, one part carbon, and three parts oxygen. Taking each of their diverse atomic masses into account, we see that 100g of baking soda contains 27.4g sodium.

    MSG (monosodium glutamate, C₅H₈NO₄Na) is only one part sodium for 5 parts carbon, 8 parts hydrogen, 1 part nitrogen, and 4 parts oxygen… And all those other atoms put together weigh a lot (comparatively), so 100g of MSG contains only 12.28g sodium.

    Q: Thanks for the info about dairy. As a vegan, I look forward to a future comment about milk alternatives

    Thanks for bringing it up! What we research and write about is heavily driven by subscriber feedback, so notes like this really help us know there’s an audience for a given topic!

    We’ll do a main feature on it, to do it justice. Watch out for Research Review Monday!

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  • This Is When Your Muscles Are Strongest

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    Dr. Karyn Esser is a professor in the Department of Physiology and Aging at the University of Florida, where she’s also the co-director of the University of Florida Older Americans Independence Center, and she has insights to share on when it’s best to exercise:

    It’s 4–5pm

    Surprise, no clickbait or burying the lede!

    This goes regardless of age or sex, but as we get older, it’s common for our circadian rhythm to weaken, which may result in a tendency to fluctuate a bit more.

    However, since it’s healthy to keep one’s circadian rhythm as stable as reasonably possible, this is a good reason to try to keep our main exercise focused around that time of day, as it provides a sort of “anchor point” for the rest of our day to attach to, so that our body can know what time it is relative to that.

    It’s also the most useful time of day to exercise, because most exercises give benefits proportional to progressive overloading, so training at our peak efficiency time will give the most efficient results. So much for those 5am runs!

    On which note: while the title says “strongest” and the thumbnail has dumbbells, this does go for all different types of exercises that have been tested.

    For more details on all of the above, enjoy:

    Click Here If The Embedded Video Doesn’t Load Automatically!

    Want to learn more?

    You might also like to read:

    The Circadian Rhythm: Far More Than Most People Know

    Take care!

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  • Undo The Sun’s Damage To Your Skin

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    It’s often said that our skin is our largest organ. Our brain or liver are the largest solid organs by mass (which one comes out on top will vary from person to person), our gut is the longest, and our lungs are the largest by surface area. But our skin is large, noticeable, and has a big impact on the rest of our health.

    The sun is one of the main damaging factors for our skin; assorted toxins are also a major threat for many people, and once the skin barrier gets broken, it’s a field-day for bacteria.

    So, what can we do about it?

    Tretinoin: the skin’s rejuvenator

    Tretinoin is also called retinoic acid, not to be mistaken for retinol, although they are both retinoids. Tretinoin is much stronger.

    As for what it’s stronger at:

    It’s usually prescribed for the treatment of sun-damage, acne, and wrinkles. Paradoxically, it works by inflaming the skin (and then making it better, and having done so, keeping it better).

    In few words: it encourages your skin to speed up its life cycle, which means that cells die and are replaced sooner, which means the average age of skin cells will be considerably younger at any given time.

    This is the same principle as we see at work when it comes to cellular apoptosis and autophagy in general, and specifically the same idea as we discussed when talking about senolytics, compounds that kill aging cells:

    Fisetin: The Anti-Aging Assassin

    About that paradoxical inflammation…

    ❝The topical use of tretinoin as an antiacne agent began almost a half century ago. Since that time it has been successfully used to treat comedonal and inflammatory acne.

    Over the intervening years, the beneficial effects of tretinoin have grown from an understanding of its potent cornedolytie-related properties to an evolving appreciation of its antiinflammatory actions.

    The topical use of clindamycin and tretinoin as a combination treatment modality that includes antibacterial, comedolytic, and antiinflammatoiy properties has proven to be a very effective therapy for treating the various stages of acne

    It is now becoming increasingly clear that there may be good reasons for these observations.❞

    ~ Drs. Schmidt & Gans, lightly edited here for brevity

    Read in full: Tretinoin: A Review of Its Anti-inflammatory Properties in the Treatment of Acne

    Against damage by the sun

    The older we get, the more likely sun damage is a problem than acne. And in the case of tretinoin,

    ❝In several well-controlled clinical trials, the proportion of patients showing improvement was significantly higher with 0.01 or 0.05% tretinoin cream than with placebo for criteria such as global assessment, fine and coarse wrinkling, pigmentation and roughness.

    Improvements in the overall severity of photodamage were also significantly greater with tretinoin than with placebo.

    Several placebo-controlled clinical studies have demonstrated that topical tretinoin has significant efficacy in the treatment of photodamaged skin. Improvements in subjective global assessment scores were recorded in:

    49–100% of patients using once-daily 0.01% tretinoin,

    68–100% of patients using 0.05% tretinoin, and

    0–44% of patients using placebo.❞

    ~ Drs. Wagstaff & Noble

    …which is quite compelling.

    Read in full: Tretinoin: A Review of its Pharmacological Properties and Clinical Efficacy in the Topical Treatment of Photodamaged Skin

    This is very well-established by now; here’s an old paper from when the mechanism of action was unknown (here in the current day, 17 mechanisms of action have been identified; beyond the scope of this article as we only have so much room, but it’s nice to see science building on science):

    ❝Tretinoin cream has been used extensively to reverse the changes of photoaging. It is the first topical therapy to undergo controlled clinical testing and proved to be efficacious. These results have been substantiated with photography, histopathologie examination, and skin surface replicas.

    Tretinoin cream has an excellent safety record; a local cutaneous hypervitaminosis A reaction is the only common problem.❞

    ~ Dr. Goldfarb et al.

    Read in full: Topical tretinoin therapy: Its use in photoaged skin

    Is it safe?

    For most people, when used as directed*, yes. However, it’s likely to irritate your skin at first, and that’s normal. If this persists more than a few weeks, or seems unduly severe, then you might want to stop and talk to your doctor again.

    *See also: Scarring following inappropriate use of 0.05% tretinoin gel

    (in the case of a young woman who used it 4x daily instead of 1x daily)

    Want to try some?

    Tretinoin is prescription-only, so speak with your doctor/pharmacist about that. Alternatively, retinal (not retinol) is the strongest natural alternative that works on the same principles; here’s an example product on Amazon 😎

    Take care!

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  • Stickers and wristbands aren’t a reliable way to prevent mosquito bites. Here’s why

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    Protecting yourself and family from mosquito bites can be challenging, especially in this hot and humid weather. Protests from young children and fears about topical insect repellents drive some to try alternatives such as wristbands, patches and stickers.

    These products are sold online as well as in supermarkets, pharmacies and camping stores. They’re often marketed as providing “natural” protection from mosquitoes.

    But unfortunately, they aren’t a reliable way to prevent mosquito bites. Here’s why – and what you can try instead.

    Why is preventing mosquito bites important?

    Mosquitoes can spread pathogens that make us sick. Japanese encephalitis and Murray Valley encephalitis viruses can have potentially fatal outcomes. While Ross River virus won’t kill you, it can cause potentially debilitating illnesses.

    Health authorities recommend preventing mosquito bites by: avoiding areas and times of the day when mosquitoes are most active; covering up with long sleeved shirts, long pants, and covered shoes; and applying a topical insect repellent (a cream, lotion, or spray).

    I don’t want to put sticky and smelly repellents on my skin!

    While for many people, the “sting” of a biting mosquitoes is enough to prompt a dose of repellent, others are reluctant. Some are deterred by the unpleasant feel or smell of insect repellents. Others believe topical repellents contain chemicals that are dangerous to our health.

    However, many studies have shown that, when used as recommended, these products are safe to use. All products marketed as mosquito repellents in Australia must be registered by the Australian Pesticides and Veterinary Medicines Authority; a process that provides recommendations for safe use.

    How do topical repellents work?

    While there remains some uncertainty about how the chemicals in topical insect repellents actually work, they appear to either block the sensory organs of mosquitoes that drive them to bite, or overpower the smells of our skin that helps mosquitoes find us.

    Diethytolumide (DEET) is a widely recommended ingredient in topical repellents. Picaridin and oil of lemon eucalyptus are also used and have been shown to be effective and safe.

    How do other products work?

    “Physical” insect-repelling products, such as wristbands, coils and candles, often contain a botanically derived chemical and are often marketed as being an alternative to DEET.

    However, studies have shown that devices such as candles containing citronella oil provide lower mosquito-bite prevention than topical repellents.

    A laboratory study in 2011 found wristbands infused with peppermint oil failed to provide full protection from mosquito bites.

    Even as topical repellent formulations applied to the skin, these botanically derived products have lower mosquito bite protection than recommended products such as those containing DEET, picaridin and oil of lemon eucalyptus.

    Wristbands infused with DEET have shown mixed results but may provide some bite protection or bite reduction. DEET-based wristbands or patches are not currently available in Australia.

    There is also a range of mosquito repellent coils, sticks, and other devices that release insecticides (for example, pyrethroids). These chemicals are primarily designed to kill or “knock down” mosquitoes rather than to simply keep them from biting us.

    What about stickers and patches?

    Although insect repellent patches and stickers have been available for many years, there has been a sudden surge in their marketing through social media. But there are very few scientific studies testing their efficacy.

    Our current understanding of the way insect repellents work would suggest these small stickers and patches offer little protection from mosquito bites.

    At best, they may reduce some bites in the way mosquito coils containing botanical products work. However, the passive release of chemicals from the patches and stickers is likely to be substantially lower than those from mosquito coils and other devices actively releasing chemicals.

    One study in 2013 found a sticker infused with oil of lemon eucalyptus “did not provide significant protection to volunteers”.

    Clothing impregnated with insecticides, such as permethrin, will assist in reducing mosquito bites but topical insect repellents are still recommended for exposed areas of skin.

    Take care when using these products

    The idea you can apply a sticker or patch to your clothing to protect you from mosquito bites may sound appealing, but these devices provide a false sense of security. There is no evidence they are an equally effective alternative to the topical repellents recommended by health authorities around the world. It only takes one bite from a mosquito to transmit the pathogens that result in serious disease.

    It is also worth noting that there are some health warnings and recommendations for their use required by Australian Pesticides and Veterinary Medicines Authority. Some of these products warn against application to the skin (recommending application to clothing only) and to keep products “out of reach of children”. This is a challenge if attached to young children’s clothing.

    Similar warnings are associated with most other topical and non-topical mosquito repellents. Always check the labels of these products for safe use recommendations.

    Are there any other practical alternatives?

    Topical insect repellents are safe and effective. Most can be used on children from 12 months of age and pose no health risks. Make sure you apply the repellent as a thin even coat on all exposed areas of skin.

    But you don’t need “tropical strength” repellents for short periods of time outdoors; a range of formulations with lower concentrations of repellent will work well for shorter trips outdoors. There are some repellents that don’t smell as strong (for example, children’s formulations, odourless formulations) or formulations that may be more pleasant to use (for example, pump pack sprays).

    Finally, you can always cover up. Loose-fitting long-sleeved shirts, long pants, and covered shoes will provide a physical barrier between you and mosquitoes on the hunt for your or your family’s blood this summer.The Conversation

    Cameron Webb, Clinical Associate Professor and Principal Hospital Scientist, University of Sydney

    This article is republished from The Conversation under a Creative Commons license. Read the original article.

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  • The Problem With Active Listening

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    The problem with active listening

    Listening is an important skill to keep well-trained at any age. It’s important in romantic relationships, parent-child relationships, friendships, and more.

    First, for any unfamiliar or hazy-of-memory: active listening is the practice of listening, actively. The “active” side of this comes in several parts:

    1. Asking helpful questions
    2. Giving feedback to indicate that the answer has been understood
    3. Prompting further information-giving

    This can look like:

    • A: How did you feel when that happened?
    • B: My heart was racing and I felt panicked, it really shocked me
    • A: It really shocked you?
    • B: Yes, because it was so unexpected; I’d never imagined something like this happening
    • A: You’d never expect something like that
    • B: No, I mean, I had no reason to

    And… As a superficial listening technique, it’s not terrible, and it has its place

    But unfortunately, if it’s one’s only listening technique, one will very quickly start sounding like a Furby—that children’s toy from the 90s that allegedly randomly parroted fragments of things that had been said to it. In fact this was a trick of programming, but that’s beyond the scope of this article.

    The point is: the above technique, if used indiscriminately and/or too often, starts to feel like talking to a very basic simulacrum.

    Which is the opposite of feeling like being listened to!

    A better way to listen

    Start off similarly, but better.

    Ask open questions, or otherwise invite sharing of information.

    People can be resistant to stock phrases like “How did that make you feel?”, but this can be got around by simply changing it up, e.g.:

    • “What was your reaction?” ← oblique but often elicits the same information
    • “I’m not sure how I’d feel about that, in your shoes” ← not even a question, but shows active attention much better than the “mmhmm” noises of traditional active listening, and again prompts the same information

    Express understanding… But better

    People have been told “I understand” a lot, and often it’s code for “Stop talking”. So, avoid “I understand”. Instead, try:

    • “I can understand that”
    • “Understandable”
    • “That makes sense”

    Ask clarifying questions… Better

    Sometimes, a clarifying question doesn’t have to have its own point, beyond prompting more sharing, and sometimes, an “open question” can be truly wide open, meaning that vaguer is better, such as:

    • “Oh?”
    • “How so?” ← this is the heavy artillery that can open up a lot

    Know when to STFU

    Something that good therapists (and also military interrogators) know: when to STFU

    If someone is talking, don’t interrupt them. If you do, they might not start again, or might skip what they were going to say.

    Interruption says “I think you’ve said all that needs to be said there”, or else, if the interruption was to ask one of the above questions, it says “you’re not doing a good enough job of talking”, and neither of those sentiments encourage people to share, nor do they make someone feel listened-to!

    Instead, just listen. Passive listening has its place too! When there’s a break, then you can go to one of the above questions/prompts/expressions of understanding, as appropriate.

    Judge not, lest they feel judged

    Reserve judgement until the conversation is over, at the earliest. If asked for your judgement of some aspect, be as reassuring as you can. People feel listened-to when they don’t feel judged.

    If they feel judged, conversely, they can often feel you didn’t listen properly, or else you’d be in agreement with them. So instead, just sit on it for as long as you can.

    Note: that goes for positive judgements too! Sit on it. Expressing a positive judgement too soon can seem that you were simply eager to please, and can suggest insincerity.

    If this seems simple, that’s because it is. But, try it, and see the difference.

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  • Power Plates – by Gena Hamshaw

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    Superfoods are all well and good, but there are only so many ways one can reasonably include watercress before it starts becoming a chore.

    Happily, Gena Hamshaw is here with a hundred single-dish vegan meals, that are not only nutritionally balanced as the subtitle promises, but also, as the title suggests, are nutritional powerhouses too.

    In the category of criticism, some ingredients are not so universally available as others. For example, depending on where you live, your local supermarket might not have freekeh, gochujang, or pomegranate molasses.

    However, most of the recipes have ingredients that are easy enough to source in any medium-sized supermarket, and for the ones that aren’t, we do recommend ordering the ingredient online and trying something you might not otherwise have experienced—that’s an important thing in life, after all!

    Bottom line: if you’d like plant-based meals that are packed full of nutrients and are delicious too, this is a top-tier recipe book.

    Click here to check out Power Plates, and enjoy a wide variety of plant-based cuisine!

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