Antidepressant Contact Lenses!

…and other items from this week’s health science news:

Seeing life in a better light?

Bringing new meaning to the idea of “looking at the world through rose-tinted glasses”, researchers at Yonsei University have developed soft, transparent contact lenses with built-in ultrathin electrodes that deliver mild electrical stimulation through the retina*, and in mice with induced depression, this treatment produced antidepressant-like effects comparable to fluoxetine (Prozac) after three weeks.

^{*because the retina is anatomically directly connected to the brain (and by some reckonings, the eyes can even be considered to be extensions of the brain), researchers used it as a non-invasive access point to influence the neural pathways involved in mood regulation.}

How it works: the lenses use temporal interference, where two harmless electrical signals intersect at precise points in the retina, allowing targeted stimulation of mood-related brain circuits, all without invasive brain implants or drugs.

What they did: depressed mice received 30 minutes of retinal stimulation daily for three weeks, and outcomes were compared with untreated depressed mice, healthy controls, and mice treated with fluoxetine.

What that did: treated mice had a 48% reduction in blood corticosterone (a stress hormone), a 47% increase in serotonin levels, and lower inflammatory markers in the brain compared with untreated depressed mice. Additionally, mice using the contact lenses showed reduced depression-like behaviors at levels similar to those seen with Prozac-treated mice.

You may be wondering how the scientists acquired depressed mice, and how they diagnosed the mental health of mice sufficiently clearly as to conduct this experiment. The answer is that they induced depression thus:

❝A chronic corticosterone-induced stress mouse model recapitulating depression-associated behavioral phenotypes was established following the protocol outlined by Pereira et al. C3H/HeNCrlOri (rd1, 25–30 g, male) mice were randomized into three groups, including the control (sham group), depression (Dep group), and TI-TES treatment (TES group). For depression induction, corticosterone by subcutaneous administration (s.c.) of a total 100 μL of corticosterone cocktail (20 mg kg⁻¹ body weight) dissolved in 20% Tween 80, 0.2% DMSO (all purchased from Sigma, St. Louis, MO), and 0.9% saline were chronically treated. It should be noted that the corticosterone paradigm used in this study does not represent human major depressive disorder itself but rather a preclinical stress model that recapitulates specific behavioral and biological features associated with depression.❞

Translated from sciencese: they gave them drugs that resulted in the same behaviors and measurable biomarkers as depression; as such, this is broadly assumed to be representative of depression in humans, but is not necessarily exactly the same thing.]

Next, up the researchers want to test long-term safety in larger animals, and customize stimulation, before human clinical trials:

Read in full: Contact lenses treat depression in mice as effectively as anti-depressant medication

Related: Does This New Machine Cure Depression?

COVID in the house? This antiviral cuts transmission by ⅔!

Researchers (Dr. Anne Luetkemeyer et al.) found that taking ensitrelvir within 72 hours of the first household member’s COVID symptom onset reduced the risk of symptomatic COVID in exposed household contacts by about two-thirds, compared to placebo.

In numbers:

• Dosage: participants took 375mg on day 1, then 125mg daily on days 2–5.
• Effect: symptomatic COVID by day 10 occurred in 2.9% of the ensitrelvir group versus 9.0% of the placebo group (a 67% relative risk reduction).
• Interpretation: in the full intention-to-treat analysis, infection occurred in 4.4% with ensitrelvir versus 10.2% with placebo (a 57% relative risk reduction).

In the US, the FDA hasn’t weighed in on this one yet, but ensitrelvir is already approved in Japan for mild-to-moderate COVID treatment and, based on this trial, for postexposure prophylaxis.

You can read more about it here:

Read in full: Antiviral ensitrelvir cuts risk of COVID-19 in household contacts by two-thirds, study finds

Related: Getting antivirals for COVID too often depends on where you live and how wealthy you are

Kratom crisis?

First, what kratom is: it’s a plant containing psychoactive compounds, most notably mitragynine, sold in powders, capsules, teas, liquid shots, and newer concentrated products such as 7-hydroxymitragynine (7-OH), which can be substantially more potent than traditional kratom.

A recent national survey analysis found kratom use in the US has reached its highest recorded level, with lifetime use rising from 1.6% of Americans aged 12+ in 2021 to 1.9% in 2024—more than 5 million people, including over 100,000 adolescents aged 12–17.

Yes, we’re getting these figures in 2026 because science takes its time sometimes (to analyze the data, get peer-reviewed, etc), so probably the numbers are even higher now.

In particular, synthetic or concentrated derivatives like 7-OH pose greater overdose or dependence risks because of much stronger opioid-like effects, and these products are increasingly sold in convenience stores and smoke shops:

Read in full: Kratom use is on the rise in the US

Related: Addiction Myths That Are Hard To Quit

Take care!