Serotonin: Benefits, Uses, Effects?
The myth of serotonin in clinical depression
E 'for decades now that the serotonin hypothesis for depression took the field and it' was accepted by legions of doctors despite the fact that the scientific evidence in its favor have decreased over time
-1 - When science is lacking
You make too much talk, and 'has rightly been said, about the little serotonin and neuroscience. As simplistic and reductionist explanations may have taken the field, even at distinguished clinicians, and 'soon said.
A complex issues are equally complex causes per se daunting, such as to tempt whoever is dealing with often quite frustrating. Industries and pharmaceutical companies have so 'ridden the wave of this "discovery" sensational around the globe hyping the benefits of drug therapy serotonin finally able to free millions of people from the burden of a syndrome so' painful and disabling. So we were able to 'release in four and quattr' eight by guilt throngs of people suffering unwary psychotherapists who had made them guilty of emergence, and in addition, a multitude of doctors and psychiatrists' was raised, now being able to have an adequate pharmaceutical paraphernalia, of 'atavistic inferiority complex' towards colleagues who specialize in other medical disciplines considered more 'scientifically based.
Everything 'shows how ridiculous a theory of the mind as one that is subject to a simple monoamine deficiency can have great success when, in addition to moving huge economic interests, go in against a primary psychological needs such as the recovery and rehabilitation of narcissistic wounds that depression and inflicts on those who 'hit, and who is dealing with the intent to cure or alleviate it, including family members.
And 'needless to add that all of this has discouraged many people who could have done so, to undertake a psychotherapeutic felt so' outdated and inappropriate, if anything, of implemented at a later time to stimulate the recovery of the patient is now "cured." In addition, due to their alleged non-hazardous 'SSRIs, namely' the specific serotonin reuptake inhibitors, are prescription around the globe also by general practitioners who, not being able to make an accurate diagnosis in the field and in the absence the rest of the time, they have not skimped in prescribe, as well as for themselves, to all those who request it or which points to vague mood disorders.
In recent years, however, after reviewing studies on previous experiments aimed at forcibly demonstrate the effectiveness of SSRIs, and 'found that the drug companies it had concealed negative results. The data on the potential dangers' of antidepressants have been covered up, such as those that showed efficacy similar to that of placebo. Nevertheless' manufacturers of pills instead of backtrack, on the other hand have tried to highlight the efficacy of SSRIs and recommending the extension of the 'use also to other diseases such as' social anxiety disorder, premenstrual dysphoric syndromes, eating disorders and those obsessive-compulsive disorder.
Now, if and 'out of the question that you are in the depressions of the chemical alterations in the functioning of certain brain circuits, this does not imply that these are the first cause, nor that serotonin has a unique role in the central general disequilibrium which determines . High amounts 'of neuromodulators in the brain does not make it more' happy. Extra doses of serotonin do not cause any benefit, or if it changes the level of serotonin in normal people causes depression.
On the other hand it should also be remembered that the DSM of 'American Psychiatric Association does not list serotonin as a cause of any explicit mental disorder.
The brain can not 'be regarded as other organs. It and 'peculiar, not only works with chemical molecules, nerve impulses, but also with thoughts, images, memories, feelings, emotions, etc.., Ie mental events' that are able to change the same synapses, the organizational structures of the circuits, and then finally the brain biochemistry.
Finally the brain and 'in close contact with the rest of the body which influences, but also from which' influenced.
The activities' such as physics seems to have substantial effects, among other things, on the chemistry of the brain and it is thought that even in older people has a power superior to antidepressant likely placebo effect of serotonin reuptake inhibitors. These effects of antidepressant, if we are generic and not lasting, could be due, inter alia, to 'increase of substances such as the' IGF-1, which stimulates the production of BDNF, a nerve growth factor and all 'anandamide , that binds to cannabinoid receptors in the brain, especially on dopaminergic neurons of the 'ATV (ventral tegmental area), whose activity' is greatly compromised or weakened, depending on the case, in depressive syndromes. L 'here anandamide acts indirectly by blocking the activity' of GABA inhibitory glutamatergic neurons that stimulate dopamine precisely the center of the 'ATV.
(A similar effect, inter alia, is obtained with the same mechanisms heroin which acts on its mu opioid receptor of the same center).
At this point we also mention, by way of example, a natural substance activating the nervous system (but there are several) known from the very 'antiques' and that 'the' St. John's Wort.
The results obtained using hypericum extracts are not inferior, if not superior, to those obtained with SSRIs apparently. It seems that the 'hypericin is able to inhibit the metabolism of numerous neurotransmitters.
As can be seen from as mentioned, partial antidepressant effects can be obtained in various ways, but certainly do not constitute a final and lasting remedy depressive disorder, which also tends to recur regularly, as many doctors know when their patients are forced to discontinue drug therapy for various reasons.
-2 - Functional characteristics of serotonin
Serotonin is synthesized from 'amino acid tryptophan content in different protein foods. Its absorption in the brain and 'instead favored by insulin and therefore the assumption of carbohydrates that stimulate it. It is everywhere, in plants, lower animals, and performs different functions depending on the species. For example, in certain lower animals has a fundamental role in learning, similar role and that 'then was hired by dopamine in higher animals, including humans.
These changes of function are common, as also happened to a derivative of serotonin, melatonin, which appeared initially in the ground to defend the first forms of life from 'aggression of' oxygen, as an antioxidant that ', and then take as a result of other properties' that we know well.
In our body serotonin and 'ubiquitous and is synthesized even 90% of the cells (ECs enterochromaffin) of the gastrointestinal tract. Only the remainder is synthesized in serotonergic neurons located in the dorsal and median raphe nuclei in the brainstem.
Serotonin in the gut contributes to the secretory and motor reflexes in the digestive tract, and 'therefore an important regulator of various gastrointestinal functions. Nell 'respiratory action has little significance on the smooth muscle of the bronchi. In the cardiovascular system has constrictive action on the arteries affecting blood pressure. Intracranial arteries in the brain such duress, and when 'heightened, can' lead to migraine attacks. Part of serotonin synthesized by cells in the blood pours EC where it helps to promote platelet aggregation.
In the nervous system serotonin-containing cell bodies are grouped to form the so-called raphe nuclei, the median and the dorsal. These innervate specifically, but sometimes overlapping, regions such as the hippocampus, the 'amygdala, the striatum, the nucleus accumbens, prefrontal cortex and several nuclei of the' hypothalamus and thalamus.
In general the serotonergic system produces effects of inhibitors bottom, but sometimes also exciters, such as that on the paraventricular nucleus of the 'hypothalamus that represents the port of stress.
A rise in the transmission of the serotonergic system reduces food intake, activity 'motor, interest in sexuality'. By inhibiting the neurons of the nucleus basalis of the forebrain serotonin induces sleep; reinforcing the GABA system in the 'amygdala dampens emotional responses, while in the hypothalamus has inhibitory effects on body temperature and sensitivity' to pain. In fact, the hypothalamic serotonin induces the increase in concentration of beta-endorphin. At the mesencephalic level average analgesic effect of exogenous and endogenous opiates. Even in the spinal cord serotonin appears to have roles in pain inhibition, intrinsic, stimulus, and cotrasmettitore with substance P.
In the prefrontal cortex, albeit with an inferior role compared to other modulators, a deficiency in serotonin transmission seems to promote attitudes of inflexibility 'cognitive. Serotonin therefore favor the inhibition of neuronal discharges impulse that reverberate in the limbic regions. It 'a modulator that can' increase the reflection, the suspension of judgment, and the implementation of rash behavior.
Ultimately what is referred to as serotonin seems to have in general a calming effect on the mind, balancing. It 'been called the police force of the mind. In fact, if the transmission and 'weak and there' turmoil in the mind and if in excess repression, suffocation.
For many 'was defined as the molecule of good humor, but from what has been mentioned does not seem to be such an opinion supported by facts. It 'true that the serotonergic system to an excitatory input on the dopaminergic of' ATV, but such modulation and 'mediated by other substances. The smoke, for example, acts in a similar way on 'ATV exciting the nicotinic receptors of' acetylcholine. The effects that do exist, but are 'moderates, I do not think that nicotine significantly alters the mood of the smoker causing a state of elation and euphoria.
Those who take substances such as' ecstasy that increase serotonergic transmission, the main effect seems to be a drastic lowering of social anxiety and therefore a state of relief, ability 'to interact, but an exaltation due' to a 'amplification of' me that feels more 'free, less oppressed than eg bound to the rules and social conventions.
From what has been said it appears that serotonin in the brain has largely inhibitory and balancing functions that have little to do with depressive symptoms that we all know.
And certainly not 'the cause, although it may' not be involved in a general imbalance that concerns a number of biochemical and structural aspects of the brain.
-3 - Stress and depression
In an 'optical stimulus-dependent, such as the one that you can' extrapolate examining the various theories that seek to give a plausible explanation to the depression, the causes that can not be searched or outside or inside of us. This is a view in which the person is seen as a passive object bombarded by stimuli from which ends up gradually to be overwhelmed.
External stimuli are usually represented by the painful events of life, from stressful situations in the long run undermine the self-esteem of the 'individual who will end' to feel more and more 'helpless in the face of reality. This is likely a gradual process of attrition that would result in a reactive depression.
The model, however, 'that' went more 'fashionable in recent decades, and' that of endogenous depression: here internal stimuli are represented by genes or by constitutional factors which would result over time in biochemical imbalances that alter in the sense the negative experience of the person.
A theory more 'complex, which could be more convincing, try to integrate into a single dynamic reactive depression and endogenous.
Initially, all forms of depression would be reactive depression but in the long run would take a nature more and more 'organic by a process of sensitization of the brain. So 'any stimulus, even the most' insignificant, would be able to trigger a depressive crisis, immediately or even belatedly.
The doubts and the lack of science 'about the serotonin theory concerning the depression we have already' spoken. The other theory questionable type of stimulus-dependent and 'stress as a factor that depressogeno. This would be considered the gateway to a view of depression reactive depression itself and the rest would be the same or later lead to a chronic state of stress. All this 'may' be plausible, but we try to clarify some concepts that are commonly given as acquired. They say that stress and 'depressogeno, but in what sense? Even in the theory of 'learned helplessness is taken for granted that an individual has to face several situations can be managed poorly or not at all.
So when it comes to stress is often referred to negative stress, the one that puts us in a serious existential crisis from which we would like to move away if possible. Stress happens to us between the head and neck, perhaps when we least expect it, a trap from which we struggle to get out there and putting so 'in crisis gradually a' psychic homeostasis already 'precarious. The 'inevitability' of the human stress in our society 'would place us all eventually more' or less at risk.
Let's try to see things in a less stimulus-dependent. In reality, 'it seems clear that on the contrary, stress is also essential for the welfare of our brain, and this since the early years of life. Our body and equipped to deal with it: there are systems that are turned off at the appropriate time as the digestive system, of sexuality 'and others such as cardiovascular and muscular hyper-activated. In order to particular hormones which are secreted in the 'adrenalin and glucocorticoids or neuromodulators such as norepinephrine and dopamine.
Although certain areas of the brain become sensitized in order to increase alertness, the 'heightened' perceptual alertness, learning.
The most 'of our brains evolved and that' the right prefrontal cortex, and 'specially equipped to deal with situations of news' that put us in trouble', in alarm, but at the same time stimulate us to find specific solutions to solve the problem and thus acquire new knowledge and skills'.
The noradrenergic nerve connections are more 'numerous in the right prefrontal cortex, and norepinephrine induces, as shown by laboratory experiments, exploratory behavior in animals in which' was injected. To deal with the reality 'in stressful situations is necessary to appeal to all resources.
In the right prefrontal cortex connections with other brain areas are well developed through the distal neurons (fusiform cells) from the long myelinated fibers and on the left prevail neurons consist of short unmyelinated fibers. All this suggests that the right prefrontal cortex and 'better equipped to deal with emergency situations as it can' appeal to the computational resources of other specialized cortical areas distant. The bark contains the left instead of the strategic models through which we pursue various goals, ultimately prescriptive models designed to solve classes of problems already 'dealt with analytically, but we can improve.
But when 'we are faced with new situations, different from the usual when we feel exposed, skilled or unskilled, and that put us in crisis, and then' the right prefrontal cortex to do more searching for new strategies, new prescriptive models. Naturally, the two parts of the brain communicate with each other and collaborate. Not always, however, 'as results from experimental investigations, people know how to use and exploit both hemispheres at the same time in the' face problematic situations.
In depressed patients the right prefrontal cortex and 'thick overactive: what' could indicate a mode 'in dealing with the reality' of prevailing sense of helplessness. Many stimuli have acquired a negative connotation. There is often in a state of chronic stress. L 'hypoactivity' front right 'instead typical of the people who call cold and insensitive, which seem not to be afraid of anything. They are people who, unfortunately, need to be activated to take risks, face dangerous situations, they go hunting for news', seeking stress to the nth degree. Do not fall into a chronic depression As long as you are able to pursue a life of adventure and full of surprises. This category includes many individuals who practice extreme sports, at risk of serious accidents.
For a proper functioning of the frontal circuits and 'require training. And 'essential that we tackle childhood experiences stress calibrated according to the level of ability' and maturity 'reach of everyone.
We should get used to perceive stress as a source of more stimulus' that threat. Instead, in the present society 'protectionism parental ends up being due to unexpected damages for future generations.
At this point, if the stress and ', or should be, a source of vitality' and growth, as ever in practice looks like this', and intriguingly inextricably linked to depression? 'Cause we need to get us in the Sermon on the element deficient and often absent instead for good or evil is the main protagonist. Between stimulus and response there is 'half of the' I ', the element that' assessing, deciding, framing situations, contextualizes, corrects, exercising self-control, anticipate, etc.. And these qualities are not given, but are acquired through experience during the various stages of development. If the prefrontal circuits are not adequately reinforced, simply not there and 'I which has its headquarters in the prefrontal cortex remains immature.
At the base of the depression there and 'fragility' of 'I, which becomes a' entities' ready to be broken up gradually from the vicissitudes of life.
People with a core of 'I more' stable tend to deal with stress in a more 'positive and constructive, and when they have to suffer they come out with more' easier '. This 'depends on the fact that the right prefrontal cortex currency more the difficulties' and news 'as opportunity' and as a source of knowledge and maturity.
Completely different and 'the perspective from which the subject deals with stress fragile, as the regressive alteration of prefrontal neuronal circuits with time tends to progress by sapping the ability' to genuinely interested, and not by calculation, to things in general and then to learn. The approach towards the world becomes so 'only superficial and in many events and abnormal situations are able to attract and then activate the dopamine system, a deputy to precisely modulate the excitatory effect in prefrontal circuits. A 'iperfrontalita' right hemisphere, in others, can 'even though' cause to cling to routine, to see any possibility of evil eye 'for change because' it feels powerless against a world full of dangers. The fragility 'of' I also should not be seen only as a purely abstract cognitive but also in the emotional. It results in a negative experience full of anguish despair emptiness that never leaves the subject and is the foundation of his life.
Such a reality 'emotional self-destructive, and as' imaginable, can not 'be tolerated and must therefore be' removed and denied. There are few, though there are those who fully accepted in their fragility 'and unworthiness', so you end up with all their might engage in defensive strategies aimed at creating a dummy I can recover the lost self-esteem.
And 'here comes the exaggerated push towards success, the' hyper-competition, compulsive perfectionism, the need to show performance continuously in order to compensate for the lack of a continuous stream of self-esteem. But this way you end up completely dependent on external reinforcements, as the 'I' and 'a pure image that tends to disintegrate and collapse at any adversity' that calls into question their self-esteem. And it 's here that we reconnect to the complex dynamics of stress. You know ', inter alia, that in humans the greater part of the stress negative concern threats to self-esteem. As for individuals who possess an ego more 'structured stress and' also a factor activation and intrinsic reinforcement acting against the backdrop of a positive basic mood, or at least not entirely negative, for those who have a rather fragile ego the situation is present in a different manner. It becomes an intrinsic need to exorcise the deep malaise from which they want to escape.
In the latter, also the hormonal response to stress seems different from the first. The stressful event induces cortisol peaks in fact more 'high adrenaline and cortisol also tend to remain more' long-circulating. And cortisol, you know, if the brain has a stimulating effect initially in the long run end up destabilizing the functionality 'of the prefrontal cortex and' hippocampus. In the latter, which has numerous receptors for cortisol with inhibitory function, it is induced cell death in the CA3 and sees suppressed neurogenesis in the dentate gyrus.
In the prefrontal cortex occurs functional alteration which results in a worsening of the working memory. To remember, then, that cortisol has an indirect inhibitory action on the serotonergic system, in that it activates an enzyme, tryptophan oxygenase which decreases at the end of the availability 'of this amino acid. It also reduces the sensitivity 'of serotonin receptors in the prefrontal cortex.
If you then want to delete the negativity 'of a basic mood depressogeno linked to fragility' of the ego, we must maintain high levels of self-esteem with the help of external reinforcements. This fictitious shaky and I 'as a torturer as always demands new performance capable of satisfying him, and since also applies in our case, the rule of habituation, and' necessary that the individual engages more and more '. Stress is not 'become a natural commitment with purpose' of development and aims to fortify the person with the most evidence 'or less harsh, but rather' a necessity 'to prevent self-esteem drops below the alert level.
Everything 'that boosts self-esteem from the outside ends to stimulate the dopamine center of' ATVs and therefore serves to keep the excitement high with purpose 'antidepressant. But stress and 'a double-edged sword. To meet the needs of an insatiable ego you engage in an excessive and there is hunting in situations that if at first appear to be able to procure the much desired positive reinforcement, are at the end of the traps as sources of frustration and attrition.
L 'exposure to stressors more' or less severe in the long run, leading to exaggerated physiological activation, promotes imbalances that alter the functionality 'of various parts of the body at the level of the immune system, cardiovascular, gastrointestinal, and so on. It should however be noted that even if the stressors are negative, they have a vital role in the mental dynamics of who goes hunting and abused.
Recently, interesting experiments in this regard have shown that in 'ATV there are two parallel circuits, one sensitive to positive emotions, and one to the negative ones or otherwise "highlights", including pain. This means that negative experiences are also able to activate it and probably will reach the maximum effect when they are both circuits at the same time to be stimulated. Cio 'would, inter alia, a justification and a physiological basis to sadomasochistic behaviors.
An 'over-stimulation of noradrenergic and dopaminergic circuits (norepinephrine plays a key role in stress) slowly leads to a depletion of these, including the serotonergic system that has a modulatory excitatory input to the locus coeruleus (noradrenergic center site in the brainstem) so that the wear of this is reflected on that of serotonin. That's at least one way in which you can 'get to a deficiency of this molecule.
At this point you are likely to exceed the threshold, the set-point beyond which you end up falling into a depressive syndrome that could also be the first of a long series. But if the subject can not now 'to appeal to any resources to be able to raise it again interrupting, even if momentarily, the vicious cycle of destructive life stressdipendente, there is' a risk that you stick in the tunnel of addiction. This fact, although they can at least make a lasting raise self-esteem more and more 'are threatened at least able to reactivate the circuits dopaminergic and noradrenergic procuring states of artificial excitement, often very intense, apparently to counter the looming depression.
The most 'intriguing behaviors of the additives and I' always seemed the apparent inconsistency 'of the experiences that involve whoever becomes the slave. Positive and negative emotions, well-being and malaise, euphoria and gloom are all aspects that intersect and that by the time they leave more and more 'space in what might seem apparently the pleasure of evil, of' self-destruction '. Elsewhere on the subject I described mechanisms similar to those mentioned above and which now seem more 'compelling and supported thanks to' advance research in the neurological field.
Finally I would like to briefly add another argument that could help to throw more shadows on the assumption monoamminica serotonin.
Serotonin is one of the main systems modulators together to 'acetylcholine, norepinephrine and dopamine. Now these, as the name suggests are part of circuits that we can define the secondary, which act, and then affect the primary circuits governed by the chemical point of view by glutamate and GABA. The branches of the systems modulators that they share some of the brainstem centers are distributed in various areas of the brain in a generalized way. You might then think that they have an effect somewhat generic. In reality, 'not' so 'because' act only in those primary circuits that are currently active, and then end up having a very specific effect.
Although their action is important and necessary but has' clear limits. Therefore act on what 'there' and not about what 'there'. Our mental states are determined by the circuit and their synaptic organization within and between them and not by chemical molecules.
Moreover, the various neuromodulators all produce the same effect, namely 'nerve impulses that are all the same and can vary only in their frequency.
Mental disorders are a consequence of the disorganization that leads to the disintegration of the transmission patterns of these same primary circuits. In turn, such a condition and 'due to the inadequacy of experiences especially children who have denied to' I grow in tune with their potential 'intrinsic. The circuits neuromodulanti, while being essential to adjust the activity 'of the primary ones, it can not change the organization, which depends only from experience. And also 'the disorganization of these in probably disrupting the balance of the circuits neuromodulanti. Therefore a rough readjustment by drugs of any deficit monoamine not 'able to change anything by mouth'.
This is evident, for example also in Alzheimer's disease, where and 'tempted by drugs to fill the deficit in cholinergic basal forebrain nucleus without significant results, with the aggravating circumstance to cause adverse side effects in patients.
At the base of the depression then you would fictitious self-esteem that hides a fragile ego unable to grow. How this' me and 'the result of regressive experiences that prompted an alteration of the circuits, and then of synaptic connections that make them up, so' such circuits could be rewired to constructive experiences can rearrange those same connections.
From this point of view in psychoanalytic theory, the weapon would be more 'effective in inducing changes in cognitive, emotional and behavioral, only that such a view was not, however,' ghettoized and affected by alternative proposals that the companies' offers and encourages.
Extrapolating from what has been discussed now we seem to see in depressive disorder a process that follows the ups and downs of a shaky and I can 'lead in some cases to those classic forms of the disease such as major depression or dysthymia chronic generally taken as a model for the distinct symptoms that distinguish them.A noi ci pare invece che non si dia abbastanza importanza ed attenzione a quelle forme depressive e mascherate ricorrenti che si possono definire sindromi ombra, riguardanti una moltitudine di persone e che hanno un andamento altalenante e apparentemente subclinico.