Friday, May 13, 2022

What Do Antidepressants Do To The Brain

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Cortisol As A Villain Of The Piece

Do Antidepressants Shrink Your Brain? No but Depression Does.

Mild stress is usually associated with successful adaptation to the environment. At the neurohistological level, mild stress is also associated with the favorable neuroplasticity changes that are described later in this article. These neurohistological changes may therefore represent the biological correlates of the learning that is responsible for adaptation to the stress.

Glucocorticoid receptors are richly expressed on neurons in the hippocampus and elsewhere in the brain. Mild stress may therefore act through physiological glucocorticoid signaling. Certainly, at physiological levels, the stress hormone cortisol stimulates hippocampal neurons and facilitates learning and memory. At pathological levels, however, cortisol overstimulates the hippocampal neurons and causes dendritic atrophy and loss of synapses whereas these structural changes are generally reversible, in extreme situations, pathological overstimulation by cortisol can also result in neuronal apoptosis. Glucocorticoid agonism in the medial prefrontal cortex also influences learning and memory: memory consolidation is facilitated, but working memory is impaired.

Interestingly, the glucocorticoid receptor antagonist mifepristone has been suggested as a treatment for psychotic depression. It may also attenuate the cognitive impairments associated with depression.

What Different Types Of Antidepressant Are There

There are several different types of antidepressant. They mostly affect the same brain chemicals and cause similar effects. But some people may respond to certain antidepressants better than others. And the different drugs may cause different side effects.

The different types are:

See our page on comparing antidepressants for a list of all antidepressants, grouped by different categories. Or see our antidepressants AZ for detailed information on individual antidepressants.

Selective serotonin reuptake inhibitors

About SSRIs:

  • SSRIs mainly work by blocking the reuptake of serotonin into the nerve cell that released it. This means that the serotonin acts for longer on your brain and body.
  • You may find the side effects of SSRIs easier to cope with than with other antidepressants. But these effects can still feel unpleasant, especially when you first start taking the drugs.
  • SSRIs are the most commonly prescribed type of antidepressant in the UK.

Serotonin and noradrenaline reuptake inhibitors

About SNRIs:

  • SNRIs work in a similar way to SSRIs. But they also have a significant effect on your noradrenaline reuptake, as well as your serotonin reuptake.
  • Like SSRIs, you may find that you can take SNRIs without experiencing too many unwanted side effects. But their side effects can still be unpleasant.
  • SNRIs are sometimes preferred for treating more severe depression and anxiety.

Tricyclics and tricyclic-related drugs

About tricyclics:

About tricyclic-related drugs:

About MAOIs:

What Happens When Ssris Are Suddenly Stopped

Going off SSRIs without tapering off of them under the direction of a psychiatrist can cause antidepressant withdrawal symptoms. Unlike withdrawal from a narcotic or powerfully addictive drug, these withdrawal symptoms arent regarded as medically dangerous, but they can be downright uncomfortable. They occur because the brains neurons havent had the chance to adapt to the suddenly reduced level of neurotransmitters. Some people experience headaches or increased irritability. Other symptoms can include nausea, insomnia, tiredness, and/or anxiety. In severe cases, a person might experience a range of flu-like symptoms that include chills and achiness.

Immediate discontinuation of SSRIs can also produce symptoms of depressionsome quite severe. Some people may even experience suicidal thoughts. This can be confusing because patients may not be able to tell if their depression is merely part of the withdrawal process or a return of their clinical depressive symptoms. According to medical practitioners, if depressive symptoms show up within days or possibly even weeks of discontinuation, they are most likely associated with SSRI withdrawal. If the symptoms develop later or gradually, they may constitute a relapse of the depression.

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Does Depression Result From A Chemical Imbalance Of The Brain

The belief that depression is a chemical imbalance caused by low serotonin levels has become widely accepted, despite there being no evidence for it. The increase in neurotransmitter levels attributed to SSRIs may contribute to depression relief, but it is not considered the main source of improvement. One reason is that the neurotransmitter changes happen immediately, but the drugs can take six weeks or more to provide relief of symptoms. Researchers believe that the time lag is due to the development of new nerve cell connectionsneuroplasticitywhich pave the way for mental and behavioral flexibility.

How Antidepressants Help Create New Connections In Our Brain


Depression has long been conceptualized as a deficiency in certain neurotransmitters. Antidepressants usually work by replenishing the levels of these neurotransmitters. However, it has been recognized that despite the antidepressants rapidly replenishing the levels of the neurotransmitters, symptom reduction requires weeks of treatment with antidepressants. Current knowledge of pharmacology and biochemical effects is readily available, however, less is known about the neurobiological and structural changes that occur while people take antidepressants.

Neuroscientists have shifted their research to the area of neuroplasticity, neurogenesis in adults, and the ability of antidepressants to regulate the expression of genes related to plasticity and resilience. It is still unknown how neuroplasticity affects mood. There are recent findings regarding the effect of antidepressants on neuroplasticity, and specific findings that suggest that antidepressants reactivate the plasticity in the adult brain such that it is comparable to those of children. This ability might be an essential part of the therapeutic action of antidepressants.

The initial studies done with rats were able to demonstrate increased neuroplasticity in the visual cortex. Later studies demonstrated that the increased neuroplasticity activated by the commencement of Fluoxetine combined with extinction training similar to Flooding in humans produced long-lasting changes in mood-related neuronal networks.

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Older Antidepressants: Tricyclics And Maois

These drugs were among the first to be used for depression. Although they’re effective, they can have serious side effects and can be especially dangerous in overdose. Nowadays, many doctors only turn to these drugs when newer — and better tolerated — medicines haven’t helped. Tricyclics and MAOIs might not be the best approach for someone who was just diagnosed. But they can sometimes be very helpful for people with treatment-resistant depression, or certain forms of depression .

Can Missing One Antidepressant Affect You

While consuming antidepressants, it is important to not miss any of your doses as it can have a serious impact on your treatment regimen. You may also suffer from withdrawal symptoms if you miss a dose of the medicine. In case you miss one of your doses, take it immediately when you remember unless it is nearly time for your next dose.

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Why Did Natural Selection Favor An Aberrant Neurohistological Response To Stress

Anxiety and fear as a result of amygdalar hyperactivity would, presumably, program the organism to avoid future exposure to potential stressors. This could have survival value for the organism and hence the species, and would therefore favor evolutionary selection. Downregulating the hippocampal and prefrontal response could be useful in this regard because, for survival value, an organism would need to react quickly to avoid stress rather than to think about the stress, analyze it and exhibit a reasoned response.

In present day humans, however, while the amygdalar response to stress could still have value, the aberrant hippocampal and prefrontal response may be an evolutionary dead weight. Arguments for the evolutionary survival value of depression have been expressed elsewhere.

Help At Fhe For Depression/ssri Taper

How Does Zoloft Work – What do SSRIs do?

FHE Health specializes in mental health treatment as well as substance addiction therapy. Our clinicians have the expertise to treat patients with all types of mood disorders, including anxiety and depression. SSRIs are an important drug in the arsenal of treatments for mental illness. Our psychiatrist and medical team prescribe them and also routinely help patients taper off of these drugs.

Its important for patients to remember that each individual, their brain chemistry, and their circumstances are different. Some people may need to rely on SSRIs for a longer period of time or indefinitely. Others will be able to safely and smartly taper off an SSRI with the help of our doctors.

If you are experiencing depression or you are thinking about stopping the use of your SSRI medication, you can rely on FHE Health for trusted medical guidance and support.

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Sequenced Treatment Alternatives To Relieve Depression

The results of the Sequenced Treatment Alternatives to Relieve Depression study are worth detailed description. This study has widely been reported as evidence that antidepressants are effective in the long-term reduction of depressive symptoms, especially if an alternative antidepressant with a broader monoaminergic profile is administered after a narrower one fails . The 3110 patients who met inclusion criteria for STAR*D were put through a maximum of four sequential pharmacological treatments, where a new treatment was initiated conditional on failing to respond to the prior one. The overall remission rate for patients who completed all treatment steps was reported to be 67% .

What Are The Side Effects Of Antidepressants

Like all medications, antidepressants can have side effects. Over half of all people who take antidepressants have side effects. They usually occur during the first few weeks of treatment and are less common later on.

Some of these side effects are believed to be a direct consequence of the medication’s effect on the brain and are relatively similar among various drugs within the same group. Examples include a dry mouth, headaches, dizziness, restlessness and sexual problems. These kinds of problems are often perceived to be side effects of the medications. But some of them may be caused by the itself.

Whether or not someone has side effects, which side effects they have, and how frequent they are will depend on the drug, the dose used, and whether they have just started taking it or have been taking it for some time. And everyone reacts slightly differently to drugs too. The risk of side effects increases if you are also taking other medication. One of the drugs may make the side effects of the other worse. These kinds of drug interactions are common in older people and people with chronic illnesses who are taking several different kinds of medication.

For this reason, it’s important to thoroughly discuss the pros and cons of the various medications with your doctor.

Some side effects are more common with particular drugs:

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What Happens If You Take Antidepressants When Not Depressed

In this article, we will be discussing the question: what happens if you take antidepressants when not depressed?. We will examine the characteristics and functioning of the brain on the consumption of antidepressants in a non-depressive state, and the common myths, misconceptions, challenges, and risks associated with antidepressants. We will also be addressing other related and relevant queries concerning antidepressants.

The Neurobiology Of Depression Can Be Understood From The Effects Of Stress


It has long been known that stress triggers and maintains the state of depression. Learning how to cope better with stress has both therapeutic and prophylactic antidepressant actions, as is evident from studies on cognitive behavior therapy . Therefore, whatever stress does to the brain may explain why depression develops. In other words, the neurochemical, neuroendocrine, neurophysiological and neurohistological effects of stress on the brain could be the biological mediators of depression in humans who are vulnerable to the disorder.

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Reuptake Inhibitors: Ssris Snris And Ndris

Some of the most commonly prescribed antidepressants are called reuptake inhibitors. What’s reuptake? It’s the process in which neurotransmitters are naturally reabsorbed back into nerve cells in the brain after they are released to send messages between nerve cells. A reuptake inhibitor prevents this from happening. Instead of getting reabsorbed, the neurotransmitter stays — at least temporarily — in the gap between the nerves, called the synapse.

What’s the benefit? The basic theory goes like this: keeping levels of the neurotransmitters higher could improve communication between the nerve cells — and that can strengthen circuits in the brain which regulate mood.

Different kinds of reuptake inhibitors target different neurotransmitters. There are three types:

What Conditions Do Ssris Treat

Although SSRIs are primarily used to treat depression, they are commonly prescribed for the treatment of anxiety and related conditions. They have also been used to treat impulse-related disorders like trichotillomania , although evidence of their efficacy for such conditions is mixed, and they are generally not a first-line treatment. They are also used to treat eating disorders, including anorexia.

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Stress And The Hippocampus

In animal models, stress-induced histological changes in the hippocampus include the following:

  • Loss of dendritic spines

  • Atrophy of the dendritic tree

  • Loss of synapses

Postmortem studies in depressed humans reveal a decrease in neuronal size, a decrease in glial size and number and a decrease in overall cortical thickness.

The prefrontal cortex regulates cognitive functions such as attention, concentration, learning and memory. The prefrontal cortex also regulates higher mental functions such as motivation and judgment. All these functions are impaired in depression, perhaps as a result of the neurohistological prefrontal changes associated with stress and depression.

Possible Side Effects Of Antidepressants

2-Minute Neuroscience: Selective Serotonin Reuptake Inhibitors (SSRIs)

I want to start this section with a research study that looked into long-term antidepressant treatment for patients with depression. There were 180 patients that included in this study and they were taking antidepressants between 3-15 years.

The findings of this study found that around 90% of people saw their depression levels decrease. This sounds very important and goes against the general topic of this article. Even though this is a high percentage of people that are having general success, theres more to the story. Along with the decrease in depression, patients reported a lot of adverse effects. These effects include

  • Around 74% of patients experience withdrawal effects
  • Around 72% of patients experience sexual problems
  • 65% of patients experience weight gain and feeling emotionally numb
  • 43% of patients became addicted

Those are just some of the adverse effects for antidepressants. Here is the full list of possible side effects from antidepressants

  • Insomnia
  • Weight Gain
  • Nausea

As you can see, there are a large amount of side effects from using these medications. Some of these side effects create other mental disorders like anxiety and sleep, which creates a vicious cycle.

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Severity Of Your Depression

Severity of depression not only increases the risk of recurrence but also needs to be considered when assessing the implication of having another episode. If you have had very severe episodes of depression and if it came on suddenly without a lot of warning then you may want to be more conservative about tapering off of the medication.

Do Antidepressants Permanently Alter Brain Chemistry

Antidepressants are designed to alter brain chemistry to alleviate symptomsthus, they do so while you are taking them. They may promote potentially beneficial structural brain changes, as well. As impressive as it may be, the brain’s neuroplasticity isn’t always positive. It’s important to realize that depression itself has been shown to alter brain chemistry and cause structural brain changes. Antidepressants are intended to improve your brain chemistry and help reverse those structural changes. Doctors caution that it can take many weeks or months before patients begin to feel better and see improvements from taking antidepressants. The experience varies from person to person. Many individuals try different kinds of antidepressants to find what works well for them and what doesn’t produce unpleasant side effects, such as dizziness, nausea, sexual dysfunction, or fatigue. For one in three people, antidepressants don’t provide any relief.

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Ssri Altered Brain Connectivity Within 3 Hours

Each subject underwent a 15-minute brain scan that measured the oxygenation of blood flow in the brain. They were then given a single dose of an SSRI known as escitalopram , before undergoing another brain scan a few hours later.

The team then measured the number of connections between voxels in the brain the equivalent to pixels in an image to create a 3D image of each brain. The 3D images of brain scans before and after SSRI usage were compared.

When analyzing the network of the whole brain, the researchers found that the SSRI reduced intrinsic connectivity levels in most areas of the brain within 3 hours. However, it increased connectivity in two specific brain regions the cerebellum and the thalamus .

We were not expecting the SSRI to have such a prominent effect on such a short timescale or for the resulting signal to encompass the entire brain, says Dr. Sacher. These findings, the researchers say, suggest that SSRIs may reorganize the brain early to reduce depressive symptoms later.

Talking to Medical News Today, Dr. Sacher said:

Our findings reveal that SSRIs affect brain connectivity right away and that these changes encompass the entire brain. It is possible that these connectivity changes are the first step in remodeling the brain, as there is evidence from other experiments that such functional connectivity changes can reflect neuroplastic change. However, additional research will be required to further unravel these mechanisms of neuroplasticity.

How Do Antidepressants Actually Work

How SSRIs and SNRIs Work For Anxiety

A recent article by Deborah Orr regarding her experiences with antidepressants sparked a lot of debate as to their merits and drawbacks. The truth is, theyre not as simple or as understood as many might think

Antidepressants the go-to treatment for depression, or generalised anxiety. Its incredible when you think about it, the fact that you can have a debilitating mood disorder, take a few pills, and feel better. Its unbelievable that medical science has progressed so far that we now fully understand how the human brain produces moods and other emotions, so can manipulate them with designer drugs.

Thats right, it is unbelievable. Because it isnt the case. The fact that antidepressants are now so common is something of a mixed blessing. On one hand, anything that helps reduce stigma and lets those afflicted know they arent alone can only be helpful. Depression is incredibly common, so this awareness can literally save many lives.

On the other hand, familiarity does not automatically mean understanding. Nearly everyone has a smartphone these days, but how many people, if pushed, could construct a touchscreen? Not many, Id wager. And so it is with depression and antidepressants. For all the coverage and opinion pieces produced about them, the details around how they work remain somewhat murky and elusive.

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