The Mind-Bending Connection Between Psychedelics and Neuroplasticity

Size does matter, at least when it comes to mental capacity! 

One of the reasons homo sapiens are the dominant species in the world has something to do with the size of their brains. At roughly 1.4 kg, the human brain is the largest of any extinct or living primate. What is more interesting is that the size of our brains has tripled throughout human evolution. Progressively larger brains helped our hominid ancestors (those of them who walked on two feet) survive hostile environmental conditions while simultaneously developing complex social structures. 

Part of the reason this evolution has been possible is because of the human brain’s heightened capacity to modify and improve itself – a characteristic called neuronal plasticity or neuroplasticity. 

What is Neuroplasticity?

The brain is made up of cells called neurons that transmit electrical signals through inter-neuronal connections called synapses. These individual connections form the basis of elaborate neural networks that the brain uses to process information and send signals to various parts of the body. Neuroplasticity refers to the brain’s lifelong ability to change these connections and networks. For the most part, this happens as part of normal brain development, but it can also be in response to repeated behavior, specific sensory inputs, new information, brain damage, or bodily trauma.

In simpler terms, neuroplasticity is the brain’s dynamic ability to modify, adapt, and optimize its structures and functions, either to incorporate new behavior or to cope with altered internal or external conditions. It has two distinct components: 

Functional neuroplasticity: the brain’s ability to move critical functions from a damaged part of itself to a healthy part.

Structural neuroplasticity: evident in the brain’s ability to change its physical structures in response to new stimuli, experience, or learning. 

Here are two examples to help understand the concept better. 

Neural networks in a young child are hyperactive, branching out in all directions, as it were, to accommodate growing physical and cognitive abilities. The medical understanding is that by the age of three years, a child’s brain is twice as active as that of an adult’s. As the brain experiences new inputs from the outside world through learning and memory, some of the networks are reinforced through regular use, while others wither out and die. This selective ability of the brain to retain certain structures and functions while eliminating others is a measure of its neuroplasticity.  

Another example of neuroplasticity can be observed in individuals who have suffered traumatic experiences like a stroke or the loss of a limb. In both these cases, the brain adapts to new environments of restricted physical abilities by rewiring the motor cortex, the part of the brain responsible for bodily movement. The outcome is functional rehabilitation, where the brain teaches itself and the body to cope with conditions like partial paralysis or the presence of a prosthesis in place of a lost limb. 

The Importance of Neuroplasticity

The human brain’s adaptive abilities can appear uncanny, even supernatural to those outside formal medical or neuroscientific training. As a result, a lot of human ingenuity, resilience, and adaptability end up being attributed to our character in general, rather than to our brains in particular. Here are a few life situations where neuroplasticity plays a pivotal role:  

• Recovery: Substance abuse can rewire brain networks to adapt to the presence of drugs and alcohol through a process called neuroadaptation. While prolonged abuse can create physical and mental dependence, neuroplasticity aids the healing and recovery process by creating new neural pathways to cope with cravings and withdrawal. The same process also helps in the recovery of patients with chronic stress.     
• Learning: There are an estimated 100 billion neurons in our brain, each capable of making trillions of connections per second with others. Processing new information or thinking about something differently creates new pathways in our brain that are reinforced with repetition. This neuroplastic process is evident in our ability to learn a new language or a musical instrument or remember complex sets of numbers or formulae.
• Emotional regulation: Think of a child waking up in a dark room, or being upset with his Christmas gift. The resulting emotions – fear and disappointment – are normal for kids. However, growing up requires some emotions to be suppressed, either for social reasons or to simply feel better. The ability to regulate emotions is another expression of neuroplasticity that can affect long-term well-being, relationships, and success at work.  
• Brain development: Although the basic structures of the brain are formed in the womb, it continues to develop throughout life. This is possible due to processes like developmental plasticity (a component of neuroplasticity) and neurogenesis (the formation of new brain cells). These processes are responsible for a wide range of adaptive behavior, from a child learning to crawl and then walk to an adult learning a complex new skill. 
• Mental health: Patients with acute mental health issues sometimes end up accepting their conditions as permanent. However, researchers believe neuroplasticity can be harnessed to promote mental health recovery. Although research into this field is still nascent, the belief is that the brain’s powers of reorganization can be utilized through behavioral therapy to reverse conditions like chronic stress, depression, and PTSD. 

The Connection Between Psychedelics and Neuroplasticity

Psychedelics are a class of mind-expanding drugs commonly referred to as hallucinogens because of their effects which include altered states of thought, perception, and awareness. They exist in both natural and synthetic forms. Ayahuasca, mescaline (found in peyote cacti), and psilocybin (derived from so-called ‘magic’ mushrooms) are all examples of natural psychedelics. Ketamine, LSD, DMT, and MDMA are just a few of the hundreds of synthetic psychedelics that have been created in laboratories. 

Clinical studies have shown that psychedelics are particularly effective in inducing neuroplasticity in the brain. Instances of structural and functional neuroplasticity have been observed in human test subjects after just a single psychedelic dose. The effects were much higher after multiple doses were administered under clinical controls. 

The most recent study published on Science reveals that psychedelics promote neuroplasticity through the activation of intracellular 5-HT2A receptors.

From what we know so far, the category of wonder drugs we call psychedelics generate brain neuroplasticity at four different levels: 

Molecular level: Psychedelics impact the brain’s signaling pathways by altering the chemical structures of certain proteins existing within brain cells. These changes, expressed at the level of genes, end up modifying the process of protein synthesis inside individual brain cells. This is a neuroplastic process that ultimately affects the transmission of electrical signals that underlies all brain activity. 

Cellular level: The effect of psychedelics at the cellular level involves both structural and functional neuroplasticity. The most prominent of these changes has to do with neuronal plasticity – the process through which neural networks in the brain acquire new structural and functional properties. More specifically, psychedelics induce neurogenesis – the creation of new brain cells or neurons.  

Synaptic level: Synapses are contacts between neurons through which electrical signals propagate. Evidence from a multitude of clinical studies indicates that psychedelics promote synaptic plasticity at both the structural and functional levels. Such changes in the activity and behavior of synapses are associated with cognitive processes such as memory formation and learning. 

Dendritic level: Dendrites are that part of a neuron that receives electrical signals from other cells. They consist of tree-like structures that branch out from the ends of a neuron. Psychedelic drugs like LSD and MDMA have been shown to increase the number and density of dendrites. These neuroplastic changes are believed to repair brain circuit malfunctions in brain circuits caused by mood and anxiety disorders.    

Positive Effects of Psychedelics on Mental Health Conditions

The resurgence of popular, academic, and clinical interest in psychedelics is one of the most promising developments in public health, specifically psychiatry, in recent decades. Research into psychedelic-assisted therapy is opening up new frontiers in our understanding of mental health conditions and effective ways of countering them.  

Psychedelics like LSD, psilocybin, MDMA, and ketamine have proven to be unbelievably effective in treating a wide variety of psychiatric disorders, from post-traumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD) to stress, anxiety, and treatment-resistant depression. A host of clinical and pre-clinical studies have also proven the remarkable long-term benefits of using psychedelics to treat conditions like drug and alcohol dependence, and eating disorders like anorexia nervosa and bulimia. 

What is most interesting about this new line of mental health treatment is not just the speed at which the therapeutic effects of psychedelics manifest (within hours in some cases), but also the lengths to which these effects continue. One study, for instance, reported significant improvements in anxiety and depression even 4.5 years after an initial administration of psilocybin. 

The future promises more insights in the use of psychedelics to effectively treat a wide range of debilitating mental health conditions. Multiple studies on psychedelics remain ongoing, and we can hope to learn much more about the mind-bending connections between psychedelics and neuroplasticity in the years to come. 

Till such time, remember that psychedelics remain prohibited in the US and most countries around the world outside of authorized research environments: They are not to be self-administered in any situation. Always consult a doctor or registered medical practitioner if you are considering psychedelic-assisted therapy for mental health improvement.