One in eight people around the world deals with mental illness, which can negatively impact their physical health, emotional well-being, and social relationships. By exploring the role of neurochemicals in the development of mental health disorders, researchers can discover new therapeutic interventions to help prevent or treat them.
Whether you’re new to neuroscience or have a working background in the field, it can be difficult to fully grasp how the complex interactions of neurochemicals within the nervous system affect brain function.
This guide provides an overview of critical neurochemicals, the impact of neurochemical imbalance, and effective treatments to help improve mental health and wellness.
What is a neurochemical?
A neurochemical is a molecule that carries chemical messages from one nerve cell (or neuron) to the next target nerve, gland, or muscle cell. The body’s vast network of nerves—the nervous system—sends and receives electrical signals that help regulate everything from breathing and muscle movement to thinking and feeling.
Additional body and brain functions that neurotransmitters help control include:
- Heartbeat and blood pressure
- Memory and learning
- Stress response and hormone regulation
- Digestion, hunger, and thirst
- Sleep, healing, and aging
What is neurochemical imbalance?
Any disruption in the complex process of neural communication can potentially upset the production or function of neurotransmitters and, consequently, impact mental health.
A neurochemical imbalance occurs when neurotransmitter levels are too high or low, which may contribute to mental health conditions including depression, anxiety, addiction, bipolar disorder, and mood swings.
However, it’s important to note that there is little evidence pointing to this imbalance alone as the only factor to explain these issues.
For example, while evidence shows that antidepressants such as selective serotonin reuptake inhibitors (SSRIs) can be effective in treating depression, the reason why is unclear. Additionally, medications aside from SSRIs have also been proven effective, which suggests the cause of depression is more than simply a neurochemical imbalance.
Some of the biological factors thought to cause neurotransmitter dysfunction (but not necessarily mental health conditions themselves) include:
- Receptors are oversensitive or insensitive to a specific neurotransmitter, causing them to over- or under-respond
- The deriving cell doesn’t pump out enough of a neurotransmitter, lessening the message
- Neurotransmitters are reabsorbed too quickly
Neurotransmitters and mental health
Identifying all the chemicals stored in neurotransmitters is a complicated process, and scientists are still working to determine how many exist.
Neurotransmitters are typically classified by their function as either excitatory, inhibitory, or modulatory, though there is some crossover within these categories.
Below are examples of four key neurotransmitters whose disruptions have been linked to various mental health issues.
Serotonin: mood regulator
Serotonin is a hormone and neurotransmitter that helps regulate anxiety, appetite, mood, sleep, and sexual behavior. SSRI medications—which prevent the reuptake of serotonin in the brain to help balance levels—are often prescribed to treat anxiety disorders, depression, and panic attacks and disorder.
Dopamine: reward neurotransmitter
Dopamine is integral to the body’s reward system, governing the ability to experience pleasure, satisfaction, and motivation. Highly addictive drugs like cocaine and amphetamines act directly on the dopamine system. ADHD, bipolar disorder, Parkinson’s disease, and schizophrenia are all associated with its dysfunction.
Norepinephrine, oxytocin, and GABA
Norepinephrine is a naturally occurring neurotransmitter that plays a vital role in the body’s fight-or-flight response by helping activate the brain and body during dangerous situations. Associated with alertness, norepinephrine is typically highest at times of stress and lowest during sleep.
Oxytocin is generally known for the bond it helps establish between mother and child. Created in the hypothalamus, this powerful hormone is essential to social recognition and sexual reproduction. During labor, oxytocin is also produced to start and strengthen contractions.
Gamma-aminobutyric acid (GABA) is an amino acid that acts as an inhibitory chemical messenger in the body. In addition to influencing motor control and vision, it also helps mediate anxiety and boost feelings of calmness. Benzodiazepines are one medication used to treat anxiety disorders by enhancing the efficacy of GABA neurotransmitters.
Neuromodulator vs. neurotransmitter
Neuromodulators are a subgroup of neurotransmitters that greatly influence cognitive function, including emotions, decision-making, social cooperation, and behavior. Among others, dopamine, norepinephrine, and serotonin are all commonly considered to be neuromodulators.
Experimental evidence and computational and theoretical models suggest that serotonin is related to risk aversion, norepinephrine to vigilance, and dopamine to positive value and reward prediction. However, it is still difficult to definitively determine the specific function of these neuromodulators.
Because of their impact on the hippocampus, amygdala, frontal cortex, and sensory cortices, neuromodulators are the primary focus of many treatment strategies for brain disorders. As researchers better understand neuromodulatory systems, the hope is that it will lead to breakthroughs in treatments.
Promoting neurochemical balance and mental well-being
As illustrated above, an imbalance of neurochemicals in the brain is associated with a variety of mental health conditions.
When it comes to depression and anxiety disorders, this imbalance is thought to be one of many potential influences, including genetics, medications, imperfect mood regulation in the brain, and environmental factors such as stressful life events.
In fact, studies of identical twins (who share the same genetic blueprint) have found that when one twin has bipolar disorder, the other has a 60 to 80 percent chance of developing it as well. For fraternal twins, the likelihood drops to only 20 percent.
When it comes to the physiology of stress, particularly if it is chronic, the resulting chemical reactions can keep the body in a perpetual fight-or-flight loop that causes negative physical and mental health impacts, including anxiety and depression.
How is a neurochemical imbalance diagnosed?
Unfortunately, there are currently no reliable tests to diagnose a neurochemical imbalance. Doctors can perform blood tests to check levels of serotonin and other neurotransmitters, but this is not necessarily indicative of the levels of neurochemicals in the brain.
Health professionals will typically assess medical history and symptoms to diagnose mental health conditions. They may start by ruling out any underlying health issues such as vitamin deficiencies or thyroid disorders, which can trigger mental health symptoms, before referring patients to a psychiatrist or psychologist for further evaluation.
Pharmaceutical interventions
There are several antidepressants and other medications available to help treat mental health disorders associated with a neurochemical imbalance. It’s important to note that because everyone responds differently to medications, it often takes time for patients to find the right treatment option.
These pharmaceuticals work by altering the available levels of dopamine, serotonin, and norepinephrine in the brain. Examples of medications used to treat a neurochemical imbalance include:
- Selective serotonin reuptake inhibitors (SSRIs) block reabsorption of serotonin, which boosts the brain’s levels of the neurotransmitter
- Serotonin-norepinephrine reuptake inhibitors (SNRIs) obstruct reabsorption of both serotonin and norepinephrine
- Norepinephrine-dopamine reuptake inhibitors (NRDIs) prevent the reabsorption of norepinephrine and dopamine
- Monoamine oxidase inhibitors (MAOIs) block the reabsorption of norepinephrine, serotonin, and dopamine
- Tricyclic antidepressants (TCAs) prevent the reabsorption of norepinephrine and serotonin
Non-pharmaceutical treatments
Particularly when used in concert with medication, psychotherapy treatments can also have a profound impact on mental health and wellness.
For instance, cognitive behavioral therapy (CBT) can help modify negative thought patterns that result from distorted belief systems. As such, treatment with a CBT therapist typically involves working to develop constructive coping methods to deal with challenging or stressful situations and reduce unwanted or unhelpful thoughts and behaviors.
In some cases, a therapist may suggest that patients keep a journal to become more aware of their self-talk and help replace self-defeating thoughts with more positive ones.
Research shows that mindfulness techniques can also improve well-being by reducing depression and anxiety symptoms. Meditation practices that specifically target worry and thought rumination are thought to be particularly beneficial.
With regular practice, meditation can train the brain to remain focused on the present and to recognize emotions and sensations without becoming completely overwhelmed by them.
Some of the physical and emotional benefits of meditation include:
- Increased self-awareness and patience
- Reduced negative emotions
- Enhanced creativity
- Increased perspective in times of stress
- Lower blood pressure and resting heart rate
- Improved quality of sleep
Explore the Neuroscience Certificate at Penn LPS Online
If you’re eager to understand the intricate connections between neural mechanisms and behavior, then the Penn LPS Online Certificate in Neuroscience is an excellent starting point.
This four-course, Ivy League program covers topics in neurochemistry, neuroendocrinology, and pharmacology while focusing on perception, mental health, social behavior, and how drugs affect central nervous system function.
The Certificate in Neuroscience also prepares you to:
- Explain the structure and role of the vertebrate nervous system, including how it applies to the neurobiology of behavior
- Understand the functions of neurochemicals that moderate and are generated by the nervous system
- Examine the roles the nervous and endocrine systems play in managing physiological and behavioral processes
- Analyze research strategies and hypotheses in neuroanatomy, neurophysiology, neurochemistry, and neuropharmacology to understand psychiatric disorders
Ready to get started? If you haven’t already, apply to Penn LPS Online today and enroll in the Certificate in Neuroscience. You can also view our course guide to learn more about what’s available in any upcoming term.
Sources
https://my.clevelandclinic.org/health/articles/22513-neurotransmitters
https://www.verywellmind.com/what-is-a-neurotransmitter-2795394
https://www.verywellhealth.com/chemical-imbalance-5191365
https://www.healthline.com/health/chemical-imbalance-in-the-brain
https://www.healthline.com/health/depression/cognitive-behavioral-therapy
