Depression Caused by Kissing? Psychiatry Hits New Low with Clickbait Fear-Mongering

Depression. It’s contagious. Through kissing.

At least this is the conclusion of a new psychiatric study that has been covered and shared widely in the days since it’s been published. It was even mentioned on Stephen Colbert, sadly without irony. It was published in Exploratory Research and Hypothesis in Medicine, which is a journal so poor that the papers it publishes have only been cited by others 36 times in its entire lifetime. The journal focuses on publishing outlandish and unconventional ideas that have little support in any mainstream scientific literature.

Notwithstanding that physical touch and intimate human connection may very well be a key antidote to depression for many, psychiatry would like you to now fear smooching with your significant other.

Psychiatry, as an ideological field, has long demonstrated its lack of ethical inquiry, empathy, or general understanding of social and relational context. But it has finally stooped so low that words fail to capture the preposterousness and gall of its suggestions.

The thrust of the article is this: the microbiome is influenced by swapping saliva. Therefore, if depression was caused by the microbiome (one theory among many), then changes to the microbiome due to kissing a depressed partner might lead to depression in the partner too.

But the paper itself is one of the worst studies I’ve seen, and is a prime example of the principle “correlation does not equal causation.”

First: their sample was patients with insomnia, not depression or anxiety. They were recruited from a sleep clinic in Iran. That also means that the paper is subject to Iranian morals around physical touch: it goes to great pains to profess that all the subjects were married before they began cohabiting, for instance. Can we trust the self-report of the participants, who may not have truthfully reported their levels of intimacy?

Moreover, their actual finding is quite unsurprising: spouses whose partners were insomniacs with emotional distress found their mental health somewhat reduced after six months of living with them, found their microbiota becoming more similar, and found their cortisol levels increased (heightened cortisol is an effect of stress, not a cause, of course).

None of this is surprising or controversial, but it also doesn’t support the causal role they claim. In the third paragraph of the study’s introduction, the authors clearly state “Salivary cortisol does not directly cause depression or anxiety.”

All opinions and jaw-dropped-on-the-floor befuddlement aside, let’s break down this academic word salad of science to understand (and correct) the logic behind this conclusion.

Oral Microbiota

Your saliva directly indicates the state of your digestive and oral health. It is made up of a delicate balance of hundreds of different bacteria, hormones, viruses, and other gross stuff most would prefer not to think about living in their mouths.

Studies have shown that people who are diagnosed with various psychiatric disorders differ from controls, on average, in their makeup of gut and oral microbiota. This isn’t too surprising nor controversial, but it has never been enough of a clear difference to actually use as a biomarker to diagnose any mental health condition.

A change in this microbiome can be caused by poor diet, stress, various drugs and pills, sleep hygiene, and the environment. Inflammation can be bi-directional, in that it both can cause and be caused by problems with the gut and mouth as well as stress.

Statistics

Statistics are great for developing computational models to estimate and predict things like economics, politics, and gambling. They also can very easily be manipulated.

In the mental health field, studies tend to rely on what’s called statistical significance. Here’s an example of a study that mimics what happens in this field: Take 100 people: 50 whose favorite color is green and 50 whose favorite color is red. Compare them on levels of anger. You give each a complicated questionnaire that assesses levels of anger and gives everyone a score. Then you use statistics to average out these scores and compare them across and within groups. Now, let’s say the results show that 23 of the green and 32 of the red score above some threshold on this questionnaire. It may show that people whose favorite color is red are more likely to be angry and that this result is statistically significant.

What does this actually show? Nothing. This study is stupid.

First, almost half of the first group are angry in this study. Second, if there were a few less folks, it might not show statistical significance at all (this is one area where manipulation comes in). Third, it could be that the 23 green people are astronomically angry and the other 27 are mildly angry, while the 32 red are just above a threshold but still mildly angry while the rest are the most peaceful people ever. Thus, statistical significance doesn’t mean real-life significance.

The most important thing to know about statistical significance can be summed up by this article:

“significant ≠ important”

Correlation is Not Causation

There is a clear correlation between the microbiome of your mouth and your emotional state. That does not mean that one causes the other. Correlation does not equal causation.

Here are just a few things that can cause both a shift in oral microbiota and your psychological well-being:

• Poverty – If you don’t have money for healthy food, you will have poor gut health and might be pretty darned stressed and unhappy
• Urban living – If you breathe in toxic air and live in a crowded metropolis, your mouth and emotions might start screaming as loud as the taxi driver stuck in traffic
• Trauma and abuse – Living in chronic fear and anger drastically impacts both your gut health (think ulcers) and your mental health
• Psychiatric drugs – If you’re already diagnosed and medicated, those drugs impact your gut health more than you may know. For instance, 95% of serotonin is produced in the intestine. What do you think the largest effect of a so-called antidepressant is?
• Reverse effects – People who are stressed, traumatized, overwhelmed, and/or lonely may eat to relieve stress. Usually stress-eating is pretty unhealthy.
• Other substance use – Alcohol, smoking, and other substance use also drastically change the biome of your mouth and belly. Guess who are the people who tend to use these substances more? Duh, people who are pretty freakin’ unhappy.

The Big Newsworthy Click-Bait Findings

Overall, the authors found that people who scored higher on insomnia, anxiety and depression had more cortisol in their spit (duh). They also found that originally “healthy” spouses married to someone who had insomnia, scored higher on measures of anxiety and depression after six months. This was especially true for female spouses.

Have you ever lived and shared a bed with someone who was struggling with insomnia? Have you ever been married to someone who was depressed and anxious? What heteronormative gender tends to be the caretaker? Have you ever taken care of someone who wasn’t sleeping and was anxious and depressed?

Is it really that surprising that living with someone who was struggling to sleep for six months would lead you to start feeling more stressed, anxious and depressed yourself? How could you not be affected by this? These are SPOUSES for cryin’ out loud – Don’t you think that when the person you love is suffering you might also start to suffer?

But, who cares because what matters to these professors of logic is that the spouse’s spit had more cortisol. So, therefore, the most likely culprit is kissing.

Psychiatry Has Lost its Mind

The headlines splashed all over the internet proclaim that depression and anxiety can be transmitted through swapping spit. Kissing can lead you to be depressed. Watch out.

This is not an Onion article, these are real news sources like Vice and the NY Post.

Instead of being laughed out of the submission room, this study was published in a so-called scientific journal and then promoted as real science demonstrating an utterly illogical conclusion from a most obvious correlation.

This in itself should lead everyone to question every psychiatric proclamation immediately, as they all are based on not so dissimilar processes of statistics and logic. It does make one wonder what psychiatry seems to have against a good make-out fest.

People who are depressed and anxious have more stress hormones in their mouth. And, living with someone who is not sleeping and is stressed is, well, depressing and stressful.

But, I guess there’s no excitement in the obvious.