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The culprit of increased depression among teens? Smartphones, new research suggests.
A new study, led by psychologist Jean Twenge, points to the screen as the problem.

- In a new study, adolescents and young adults are experiencing increased rates of depression and suicide attempts.
- The data cover the years 2005–2017, tracking perfectly with the introduction of the iPhone and widespread dissemination of smartphones.
- Interestingly, the highest increase in depressive incidents was among individuals in the top income bracket.
The recent terrorist attack that killed 50 people in New Zealand mosques has been dubbed "a mass shooting of, and for, the internet." Livestreamed on Facebook, the killer referenced a controversial YouTube star before he began his shooting spree. Many of the negative effects of social media are really just beginning to be known. So far, it's not looking good.
Not that social media is inherently bad — this is not a binary media. It does not necessarily cause mental health issues. What it is doing, however — especially in young people, a new study argues — is exploiting depressive and suicidal tendencies. And it appears that this trend is especially insidious in the developing minds of teenagers and young adults.
The study, which was published in Journal of Abnormal Psychology on March 14, was led by psychologist Jean Twenge at San Diego State University. The author of iGen and Generation Me, Twenge has devoted her career to researching the effects of technology and social media on the adolescent brain (among others). Her 2017 article in The Atlantic speculated that teenagers and young adults are experiencing increased mood disorder problems that correlate perfectly with the release of the iPhone.
This problem is affecting every generation (or cohort) in some manner. Depression-related expenses currently cost the United States $106–$118 billion annually. A major depressive disorder will affect one in six people during their lives; 17 percent of those experiencing treatment-resistant depression attempt suicide. More contemplate it. Currently, about 45,000 Americans take their own lives every year.
For this study, Twenge and her partners hone in on data from 2005 to 2017. They wanted to know what age groups were most affected by increased instances of depression. Incidence of mood disorders, they write, "generally lessens with age." In the date range cited, depressive incidents among adolescents aged 12 to 17 increased by 52 percent (8.7 percent to 13.2 percent); between 2009-2017, they increased 63 percent among young adults aged 18-25 (8.1 percent to 13.2 percent).
iGen: The Smartphone Generation | Jean Twenge | TEDxLagunaBlancaSchool
These statistics were pulled from annual surveys conducted by the U.S. Substance Abuse and Mental Health Services Administration, which included data from 212,913 adolescents and 398,967 young adults. These cohorts were not the only two to experience an uptick in depression. In fact, alongside adolescents, Boomers were observed to be most affected. As the researchers write,
"The effects were primarily due to cohort, with the Boomer cohorts of the 1950s and the iGen cohorts of the late 1990s the most likely to experience serious psychological distress, MDE in the last year, and suicide-related outcomes."
Increases were most stark among women. Though the trend affected white Americans most, increased distress was observed across racial and ethnic groups. Mood disorders were worst in individuals in the highest income bracket. Interestingly, given the timeline of the results, the researchers are confident that neither economic conditions or drug or alcohol use (rates have remained steady or are falling, depending on cohort) are to blame.
They also feel that neither self-reporting or opioid usages is behind this uptick. Willingness to admit emotional problems couldn't account for all of the observed trends; opioid addiction predominantly affected particular cohorts.
There are two trends that do appear to be causing this problem, however.
"Another possibility is that the increased use of electronic communication and digital media during this time period may have changed modes of social interaction enough to affect mood disorders and suicide-related outcomes. For example, individuals who spend more time on social media and less time with others face-to-face report lower well-being and are more likely to be depressed."
Tied into increased screen time, which could lead to engaging in or being the victim of cyber-bullying, is sleep issues. Sleep duration is declining among all age groups, but especially adolescents and young adults during a time in life when they need it the most. Lack of sleep has been linked to mood disorders, suicidal ideation, and suicide attempts.
Though the internet is also used as a form of connectivity — say, in this case, to seek counseling for psychological problems and mood disorders — the researchers suggest further studies on how best to leverage technology for the support of individuals.
In her Atlantic article, Twenge points to a number of disturbing trends among teens: hanging out with friends less; dating less; having sex less; sleeping less. All of that time not doing those activities appear to be spent in front of a screen, making another finding — feeling isolated and lonely — rather obvious.
Utilizing the tech for good is one step forward. But another would be to put the phone down more often. A challenging prospect, given how tied into our lives they've become. If you've only grown up in a world viewed through a screen, learning that other worlds — namely, the real one — exist might seem impossible. Yet some distance is feeling more necessary by the day.
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How tiny bioelectronic implants may someday replace pharmaceutical drugs
Scientists are using bioelectronic medicine to treat inflammatory diseases, an approach that capitalizes on the ancient "hardwiring" of the nervous system.
Left: The vagus nerve, the body's longest cranial nerve. Right: Vagus nerve stimulation implant by SetPoint Medical.
- Bioelectronic medicine is an emerging field that focuses on manipulating the nervous system to treat diseases.
- Clinical studies show that using electronic devices to stimulate the vagus nerve is effective at treating inflammatory diseases like rheumatoid arthritis.
- Although it's not yet approved by the US Food and Drug Administration, vagus nerve stimulation may also prove effective at treating other diseases like cancer, diabetes and depression.
The nervous system’s ancient reflexes
<p>You accidentally place your hand on a hot stove. Almost instantaneously, your hand withdraws.</p><p>What triggered your hand to move? The answer is <em>not</em> that you consciously decided the stove was hot and you should move your hand. Rather, it was a reflex: Skin receptors on your hand sent nerve impulses to the spinal cord, which ultimately sent back motor neurons that caused your hand to move away. This all occurred before your "conscious brain" realized what happened.</p><p>Similarly, the nervous system has reflexes that protect individual cells in the body.</p><p>"The nervous system evolved because we need to respond to stimuli in the environment," said Dr. Tracey. "Neural signals don't come from the brain down first. Instead, when something happens in the environment, our peripheral nervous system senses it and sends a signal to the central nervous system, which comprises the brain and spinal cord. And then the nervous system responds to correct the problem."</p><p>So, what if scientists could "hack" into the nervous system, manipulating the electrical activity in the nervous system to control molecular processes and produce desirable outcomes? That's the chief goal of bioelectronic medicine.</p><p>"There are billions of neurons in the body that interact with almost every cell in the body, and at each of those nerve endings, molecular signals control molecular mechanisms that can be defined and mapped, and potentially put under control," Dr. Tracey said in a <a href="https://www.youtube.com/watch?v=AJH9KsMKi5M" target="_blank">TED Talk</a>.</p><p>"Many of these mechanisms are also involved in important diseases, like cancer, Alzheimer's, diabetes, hypertension and shock. It's very plausible that finding neural signals to control those mechanisms will hold promises for devices replacing some of today's medication for those diseases."</p><p>How can scientists hack the nervous system? For years, researchers in the field of bioelectronic medicine have zeroed in on the longest cranial nerve in the body: the vagus nerve.</p>The vagus nerve
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTYyOTM5OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NTIwNzk0NX0.UCy-3UNpomb3DQZMhyOw_SQG4ThwACXW_rMnc9mLAe8/img.jpg?width=1245&coordinates=0%2C0%2C0%2C0&height=700" id="09add" class="rm-shortcode" data-rm-shortcode-id="f38dbfbbfe470ad85a3b023dd5083557" data-rm-shortcode-name="rebelmouse-image" data-width="1245" data-height="700" />Electrical signals, seen here in a synapse, travel along the vagus nerve to trigger an inflammatory response.
Credit: Adobe Stock via solvod
<p>The vagus nerve ("vagus" meaning "wandering" in Latin) comprises two nerve branches that stretch from the brainstem down to the chest and abdomen, where nerve fibers connect to organs. Electrical signals constantly travel up and down the vagus nerve, facilitating communication between the brain and other parts of the body.</p><p>One aspect of this back-and-forth communication is inflammation. When the immune system detects injury or attack, it automatically triggers an inflammatory response, which helps heal injuries and fend off invaders. But when not deployed properly, inflammation can become excessive, exacerbating the original problem and potentially contributing to diseases.</p><p>In 2002, Dr. Tracey and his colleagues discovered that the nervous system plays a key role in monitoring and modifying inflammation. This occurs through a process called the <a href="https://www.nature.com/articles/nature01321" target="_blank" rel="noopener noreferrer">inflammatory reflex</a>. In simple terms, it works like this: When the nervous system detects inflammatory stimuli, it reflexively (and subconsciously) deploys electrical signals through the vagus nerve that trigger anti-inflammatory molecular processes.</p><p>In rodent experiments, Dr. Tracey and his colleagues observed that electrical signals traveling through the vagus nerve control TNF, a protein that, in excess, causes inflammation. These electrical signals travel through the vagus nerve to the spleen. There, electrical signals are converted to chemical signals, triggering a molecular process that ultimately makes TNF, which exacerbates conditions like rheumatoid arthritis.</p><p>The incredible chain reaction of the inflammatory reflex was observed by Dr. Tracey and his colleagues in greater detail through rodent experiments. When inflammatory stimuli are detected, the nervous system sends electrical signals that travel through the vagus nerve to the spleen. There, the electrical signals are converted to chemical signals, which trigger the spleen to create a white blood cell called a T cell, which then creates a neurotransmitter called acetylcholine. The acetylcholine interacts with macrophages, which are a specific type of white blood cell that creates TNF, a protein that, in excess, causes inflammation. At that point, the acetylcholine triggers the macrophages to stop overproducing TNF – or inflammation.</p><p>Experiments showed that when a specific part of the body is inflamed, specific fibers within the vagus nerve start firing. Dr. Tracey and his colleagues were able to map these relationships. More importantly, they were able to stimulate specific parts of the vagus nerve to "shut off" inflammation.</p><p>What's more, clinical trials show that vagus nerve stimulation not only "shuts off" inflammation, but also triggers the production of cells that promote healing.</p><p>"In animal experiments, we understand how this works," Dr. Tracey said. "And now we have clinical trials showing that the human response is what's predicted by the lab experiments. Many scientific thresholds have been crossed in the clinic and the lab. We're literally at the point of regulatory steps and stages, and then marketing and distribution before this idea takes off."<br></p>The future of bioelectronic medicine
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTYxMDYxMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNjQwOTExNH0.uBY1TnEs_kv9Dal7zmA_i9L7T0wnIuf9gGtdRXcNNxo/img.jpg?width=980" id="8b5b2" class="rm-shortcode" data-rm-shortcode-id="c005e615e5f23c2817483862354d2cc4" data-rm-shortcode-name="rebelmouse-image" data-width="2000" data-height="1125" />Vagus nerve stimulation can already treat Crohn's disease and other inflammatory diseases. In the future, it may also be used to treat cancer, diabetes, and depression.
Credit: Adobe Stock via Maridav
<p>Vagus nerve stimulation is currently awaiting approval by the US Food and Drug Administration, but so far, it's proven safe and effective in clinical trials on humans. Dr. Tracey said vagus nerve stimulation could become a common treatment for a wide range of diseases, including cancer, Alzheimer's, diabetes, hypertension, shock, depression and diabetes.</p><p>"To the extent that inflammation is the problem in the disease, then stopping inflammation or suppressing the inflammation with vagus nerve stimulation or bioelectronic approaches will be beneficial and therapeutic," he said.</p><p>Receiving vagus nerve stimulation would require having an electronic device, about the size of lima bean, surgically implanted in your neck during a 30-minute procedure. A couple of weeks later, you'd visit, say, your rheumatologist, who would activate the device and determine the right dosage. The stimulation would take a few minutes each day, and it'd likely be unnoticeable.</p><p>But the most revolutionary aspect of bioelectronic medicine, according to Dr. Tracey, is that approaches like vagus nerve stimulation wouldn't come with harmful and potentially deadly side effects, as many pharmaceutical drugs currently do.</p><p>"A device on a nerve is not going to have systemic side effects on the body like taking a steroid does," Dr. Tracey said. "It's a powerful concept that, frankly, scientists are quite accepting of—it's actually quite amazing. But the idea of adopting this into practice is going to take another 10 or 20 years, because it's hard for physicians, who've spent their lives writing prescriptions for pills or injections, that a computer chip can replace the drug."</p><p>But patients could also play a role in advancing bioelectronic medicine.</p><p>"There's a huge demand in this patient cohort for something better than they're taking now," Dr. Tracey said. "Patients don't want to take a drug with a black-box warning, costs $100,000 a year and works half the time."</p><p>Michael Dowling, president and CEO of Northwell Health, elaborated:</p><p>"Why would patients pursue a drug regimen when they could opt for a few electronic pulses? Is it possible that treatments like this, pulses through electronic devices, could replace some drugs in the coming years as preferred treatments? Tracey believes it is, and that is perhaps why the pharmaceutical industry closely follows his work."</p><p>Over the long term, bioelectronic approaches are unlikely to completely replace pharmaceutical drugs, but they could replace many, or at least be used as supplemental treatments.</p><p>Dr. Tracey is optimistic about the future of the field.</p><p>"It's going to spawn a huge new industry that will rival the pharmaceutical industry in the next 50 years," he said. "This is no longer just a startup industry. [...] It's going to be very interesting to see the explosive growth that's going to occur."</p>Just how cold was the Ice Age? New study finds the temperature
Researchers figure out the average temperatures of the last ice age on Earth.
Icebergs.
- A new study analyzes fossil data to find the average temperatures during the last Ice Age.
- This period of time, about 20,000 years ago, had the average temperature of about 46 degrees Fahrenheit (7.8 C).
- The study has implications for understanding climate change.
Surface air temperatures during the last ice age.
Credit: Jessica Tierney, University of Arizona
Best. Science. Fiction. Show. Ever.
"The Expanse" is the best vision I've ever seen of a space-faring future that may be just a few generations away.
- Want three reasons why that headline is justified? Characters and acting, universe building, and science.
- For those who don't know, "The Expanse" is a series that's run on SyFy and Amazon Prime set about 200 years in the future in a mostly settled solar system with three waring factions: Earth, Mars, and Belters.
- No other show I know of manages to use real science so adeptly in the service of its story and its grand universe building.
Credit: "The Expanse" / Syfy
<p>Now, I get it if you don't agree with me. I love "Star Trek" and I thought "Battlestar Galactica" (the new one) was amazing and I do adore "The Mandalorian". They are all fun and important and worth watching and thinking about. And maybe you love them more than anything else. But when you sum up the acting, the universe building, and the use of real science where it matters, I think nothing can beat "The Expanse". And with a <a href="https://www.rottentomatoes.com/tv/the_expanse" target="_blank">Rotten Tomato</a> average rating of 93%, I'm clearly not the only one who feels this way.</p><p>Best.</p><p>Show.</p><p>Ever. </p>How exercise changes your brain biology and protects your mental health
Contrary to what some might think, the brain is a very plastic organ.
As with many other physicians, recommending physical activity to patients was just a doctor chore for me – until a few years ago. That was because I myself was not very active.
Here's a 10-step plan to save our oceans
By 2050, there may be more plastic than fish in the sea.
