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Wagamaga OP t1_j8xc96f wrote

In many patients, depression is associated with memory dysfunction. Now the results of a large study involving brain scans show that patients with moderate to severe depression have 7-10 per cent fewer serotonin 4 receptors in the brain than healthy test subjects.

The researchers from the University of Copenhagen, Psychiatry in the Capital Region and Rigshospitalet performed PET scans of 90 patients with depression who still had not received treatment and just as many healthy test subject of the same age. A PET scan will reveal the amount of serotonin 4 receptors in the brain.

“You cannot tell from a scan whether a person is depressed or not. But we could tell that there was a difference between the patients and the test subjects. The former had fewer serotonin 4 receptors,” says Clinical Professor Gitte Moos Knudsen from the Department of Clinical Medicine and the Neurobiological Research Unit at Rigshospitalet.

Largest PET brain scan study of its kind Previous studies have shown that the serotonin 4 receptor affects the risk of depression, while others have shown that it is associated with human memory. The new results, which have just been published in the scientific journal JAMA Psychiatry, are based on the largest PET brain scan study ever to have been conducted on patients suffering from depression. The aim of the study was to describe the connection between depression, memory dysfunction and low receptor levels.


MRSN4P t1_j8xrobb wrote

Very interesting. This begs the question of whether serotonin impacting medications (SSRIs, etc) affect memory performance in people with and without depression.


peer-reviewed-myopia t1_j8xwm8t wrote

I don't understand the value of this research. Depression has been known to correlate with memory dysfunction and decreased hippocampal volume. 5-HT4 (serotonin 4) receptors have been known to be involved with memory, and the structural plasticity effects within the hippocampus.

However, compared to other serotonin receptors, the function of 5-HT4 throughout the brain and periphery is diverse and complex — which makes sense when considering how relatively large / complicated the gene encoding 5-HT4 is, and how little is known about the regulation of its transcription.

There is strong evidence regarding the involvement of 5-HT4 in depression, but imaging that quantifies global reductions is completely insufficient. Humans show different responses in 5-HT4R expression in different brain regions. SSRIs have been shown to decrease global 5-HT4 binding. Depressed suicide victims show increased 5-HT4 receptor binding in the caudate nucleus and frontal cortex.

This study has zero value in paving the way for new drugs.


virgilreality t1_j8yo28m wrote

This is completely true, based on personal experience.


sgramstrup t1_j8z69eq wrote

> This study may pave way for new drugs.

It would be nicer if it could pave the way to hindering depression, but I guess we all have different incentives..


fl135790135790 t1_j8zmjf6 wrote

For what it’s worth, I was put on Remeron for general anxiety. Apparently it’s a bit different from regular antidepressants/anti anxiety and rarely has side effects.

My memory is 50x what it was before. I can glance at a piece of junk mail that mentions a class action lawsuit hearing that’s on October 5th and to call or email before August 8th to be considered part of the suit.

It’s pretty bizarre.


ciras t1_j8zvprw wrote

> there was a correlation between cerebral 5-HT4 receptor binding and verbal memory (r = 0.29; P = .02)

a correlation of r=0.29 is absolutely abysmal, look at the graphs they provided and tell me with a straight face these "correlations" mean anything


bog_w1tch t1_j901ciq wrote

As someone who suffered from clinical depression for ~4 years, my brain does not function like it did before, particularly regarding memory. It feels fundamentally different.


Ingolfthecat t1_j908v9e wrote

So does SSRI treatment reverse memory-loss to any degree? I know from experience that memory loss can make it difficult to engage socially which is important for beating the depression


mrb783 t1_j911z0k wrote

That reminds me of a study I read where depression can lead to memory dysfunction. Memory dysfunction was in a story I read about depression.

But, yeah, all joking aside, I super relate to this.


redvodkandpinkgin t1_j912bed wrote

I don't know the study you reference, but SSRIs and SNRIs were shown to improve depression over placebos countless times for a long time now. It's no miracle, mind you, but it still works at least better than nothing


romacopia t1_j913rb0 wrote

I wonder if psychedelic drugs can improve memory function. LSD, psilocybin, and MDMA are serotonin receptor agonists.


redvodkandpinkgin t1_j91kyp0 wrote

That study defends my point though. It's right in the abstract

>Results The random effects mean difference between drug and placebo favored drug (1.75 points, 95% confidence interval 1.63 to 1.86). Differences between drug and placebo increased significantly (P<0.001) with greater baseline severity. After controlling for participant characteristics at baseline, no trends in treatment effect or placebo response over time were found. The best fitting model of response distributions was three normal distributions, with mean improvements from baseline to end of treatment of 16.0, 8.9, and 1.7 points. These distributions were designated Large, Non-specific, and Minimal responses, respectively. Participants who were treated with a drug were more likely to have a Large response (24.5% v 9.6%) and less likely to have a Minimal response (12.2.% v 21.5%).

Depression is an insanely difficult to treat disorder. There is no one drug that cures it or even makes it manageable for everyone; hell, they din't help me a whole lot with it. But the medicine works for some people. More importantly, it seems to help more those with a more severe depression. It's no miracle, but it can help some together with therapy.

We still don't have a good drug for it, sure, but it's not like a placebo, it does help.


InTheEndEntropyWins t1_j91lm2p wrote

I suspect this is just a correlation thing rather than causative. For your brain to function properly you need to have a good diet, sleep and exercise. If you aren't doing those then your brain isn't going to work properly showing up as things like memory dysfunction and depression.

We have studies that show the causal effect of exercise and have a ideas on the mechanisms why

>Aerobic exercises, including jogging, swimming, cycling, walking, gardening, and dancing, have been proved to reduce anxiety and depression.3 These improvements in mood are proposed to be caused by exercise-induced increase in blood circulation to the brain and by an influence on the hypothalamic-pituitary-adrenal (HPA) axis and, thus, on the physiologic reactivity to stress.3 This physiologic influence is probably mediated by the communication of the HPA axis with several regions of the brain, including the limbic system, which controls motivation and mood; the amygdala, which generates fear in response to stress; and the hippocampus, which plays an important part in memory formation as well as in mood and motivation.


We have studies showing that exercise is just as effective as medicine in treating depression

>Four trials (n = 300) compared exercise with pharmacological treatment and found no significant difference (SMD -0.11, -0.34, 0.12). From

Exercise has massive effects on mitochondria, which might be partly a mechanism in relation to depression. >Mitochondria Linked to Major Depression in Older Adults>


Depression is linked to lower brain volume

>Conclusion: Our results suggest that lower CV fitness and exaggerated exercise BP and HR responses in middle-aged adults are associated with smaller brain volume nearly 2 decades later. Promotion of midlife CV fitness may be an important step towards ensuring healthy brain aging.


>We found that longitudinal measures of cortical atrophy were widely correlated with sleep quality.


>A better diet quality is associated with larger brain tissue volumes.


>This study shows that a more severe and chronic lifetime disease course in MDD is associated with reduced volume in brain regions relevant for executive and cognitive functions and emotion regulation in a large sample of patients representing the broad heterogeneity of MDD disease course.>

Sleep is really important, if you aren't sleeping properly you have have a tenfold higher risk of depression,

>People with insomnia , for example, may have a tenfold higher risk of developing depression From

Then there is diet

>The diet may have a significant effect on preventing and treating depression for the individual. A diet that protects and promotes depression should consist of vegetables, fruits, fibre, fish, whole grains, legumes and less added sugar, and processed foods. In the public health nurse’s preventative and health-promoting work, support and assistance with changing people’s dietary habits may be effective in promoting depression. From


>Current evidence supports the finding that omega-3 PUFAs with EPA ≥ 60% at a dosage of ≤1 g/d would have beneficial effects on depression Https://


InTheEndEntropyWins t1_j91mlec wrote

There was a study saying that there is no good evidence that low serotonin levels being related to depression.

SSRI's do work for some people but they aren't fixing any underlying chemical imbalance in the brain. Think of them as a painkiller, they help with the symptoms but aren't fixing some underlying issue.