Cognition

Peptides for Depression | What to Know in 2024

For decades scientists and doctors have operated under the premise that a “chemical imbalance” is the underlying cause of depression. The prevailing theory has been that if a person’s serotonin, norepinephrine, or dopamine levels were out of balance then that person would develop depression. It seemed logical then that correcting those levels, usually by raising them, was the best way to treat depression.The result of the “chemical imbalance” hypothesis was an explosion of selective serotonin reuptake inhibitors (SSRIs), like Prozac and Zoloft, in addition to MAOIs, SNRIs, tricyclic antidepressants, and drugs targeting norepinephrine and dopamine levels. In the early 1990s, these drugs were touted as being 80-90% effective in treating depression and related conditions. As a result, they quickly became some of the most-prescribed drugs in the western world. Unfortunately, these wounder drugs were given far more credit than they were due, perhaps in no small part because people and their medical providers were desperate to have anything they could use to fight back against the symptoms of depression.As it turns out, more recent studies have shown that drugs like Prozac are no more effective in treating depression than placebo[1]. For a long time, no one wanted to talk about this because, well, there wasn’t much of an alternative. Over time, however, doctors were forced to face the fact that SSRIs and similar drugs simply weren’t up to the task they were developed for. Far from being a nadir in depression research, however, this revelation spurred the development of new hypotheses and resulted in the investigation of multiple new treatments for depression including peptides, electroconvulsive therapy, and even drugs like ketamine.

Peptides for the Brain | What to Know in 2024

The last decade has witnessed an explosion of research into the effects of peptides for brain and central nervous system. As a result of this research, science has come to understand that multiple peptides have a complex and nuanced effect on the brain under both physiological circumstances as well as pathological conditions. What is even more interesting is that the last 10 years have revealed that early research for brain peptides, in many cases, incorrectly identified the peptide’s major role. In other words, for a long time, science has not known what the major roles of specific peptides are in the brain. It is only recently that research has become sophisticated enough to the point that we are finally beginning to understand the most important roles of peptides for the brain.

Peptides for the Brain

Most neurotransmitters, which is to say the molecules that help to send messages from one part of the brain to the other, are peptides or derivatives of peptides. Things like serotonin, norepinephrine, and dopamine, which are the fundamental communication molecules of the central nervous system, are all derivatives of peptides and amino acids. They play the role of final chemical messengers, helping one neuron to communicate with the next in one in the chain so that a signal can move from neuron to neuron across the brain. These molecules are generalists, however, and manipulating them has a global effect on the function of the brain rather than a targeted effect.

Recent research, especially in animals, as revealed that there are other peptides that have more specific functions in the brain than the general neurotransmitters mentioned above. This research is helping to rewrite our understanding of how brain function is controlled and giving us new tools for manipulating everything from sleep quality to memory to mood.

Cognition is a complex system encompassing processes such as episodic memory, working memory, executive function/inhibition, spatial learning, language/vocabulary comprehension, processing speed, and language/reading decoding. Changes in synaptic plasticity, the ability of the brain to change and adapt to new information, can be short lived from milliseconds to years. Short lived forms include facilitation, augmentation, and potentiation which enhances neurotransmitter release.

These dynamic changes represent the molecular basis for learning and memory. This synaptic plasticity can be influenced by several factors e.g., aging, diseases (obesity, diabetes, hypertension, dyslipidemia), toxins (smoking and alcohol), and exercise. Aging has been estimated to trigger performance decline with an incidence of mild cognitive impairment of 21.5–71.3 per 1000 person-years). Cortical thickness and subcortical volume are shrinking 0.5–1% annually as a morphological sign of cognitive decline with plaques and axonal degeneration. Dementia is diagnosed when the acquired cognitive impairment has become severe enough to compromise social and/or occupational functioning with increasing prevalence.

Worldwide, around 50 million people have dementia and, with one new case every three seconds, the number of people with dementia is set to triple by 2050. Thus, there is a huge need for new research in order to combat the above-mentioned metrics. The peptides below have undergone extensive research to help aid in the improvement for our neurocognitive system.

Selank

Both Selank and Semax are melanocortin’s and have pleiotropic effects involved in brain health and function. Selank by itself has traditionally been prescribed for anxiety and depression. Selank has pronounced anxiolytic activity and acts as a stable neuropsychotropic, antidepressant, and anti-stress medication.

Semax

Semax is used as a therapeutic with pathologies related to brain circulation dysfunction. As a combination, Selank/Semax has applications in improving learning processes, exploratory behavior, regeneration and development, nociceptive and in amatory processes, accelerate nerve regeneration and improve neuromuscular performance and overall neural health.

TB-500 is also known as thymosin beta 4 (TB4). Thymosin Beta 4 has been found, in animal models, to play a central role in controlling the structure of cells. By improving cell structure, TB-500 is thought to aid in wound healing, improve cell responses to stress, and even help cells to live longer. Scientific animal research studies have shown that TB-500’s role in regulating cell structure may eventually make it a leading therapeutic in wound healing, blood vessel repair, and even ocular (eye) repair.

Research has shown that when it comes to brain health, there are few drugs, supplements, or diets that make much difference. Unfortunately, the brain has remained a mystery to medical science and thus efforts to determine how to keep the brain healthy have been hindered. Science can tell us only that regular exercise and a relatively meat-free diet are associated with long-term brain health. There may, however, be some new evidence regarding thymosin beta 4 (also known as TB-4, or TB-500) and its impact on neural health.

Thymosin Beta 4

TB-500 (TB-4) is a naturally occurring peptide that is known to produce a vast array of healing and regenerative effects. It appears to promote everything from bone remodeling and growth after fracture to healing of heart muscle after a myocardial infarction (heart attack). Recent research in rats now suggests that TB-500 (TB-4) may improve neurological outcomes after stroke or brain damage.