Neurotransmitters: symptoms of chemical imbalances in the brain, including questionnaires

neurotransmitters deficiency symptoms sources

Neurotransmitters, together with hormones, are the chemical messengers in our body, mainly in the brain. In total, there are more than 50 different neurotransmitters in the brain. They regulate our state of mind, our motivation, energy, learning ability, and much more. When these become imbalanced, we can feel very annoyed and frustrated, and our behavior can change very strongly under the influence of an imbalance in our neurotransmitter system.

When neurotransmitters become imbalanced, we can experience a wide range of symptoms. A deficiency can manifest with depression and anxiety (serotonin), laziness, anger, and lack of motivation (dopamine). Other symptoms can be panic attacks, stress and inability to calm down (GABA), heart palpitations, intolerance to exercise (norepinephrine). Bad memory and focus problems can be a result of an acetylcholine deficiency.

Imbalances neurotransmitters

The way neurotransmitters work in our brains and how specific imbalances manifest themselves can influence a possible imbalance between the different signal substances in the short and long term.

When you have read this page completely, you will have a good understanding of:

  • the action and functions of the main neurotransmitters
  • how to recognize symptoms
  • Based on the yes / no questionnaires, you can see which symptoms are related to which neurotransmitter.

Roles of neurotransmitters and synapses

The cells in our brain communicate through synapses. You can think of a nerve cell as a kind of spider web with many small nodes protruding at the end of branch-like structures. At the ends of these branches are presynaptic and postsynaptic cells where nerve cells communicate through chemical signaling molecules, known as neurotransmitters.

There is a small gap at the junctions between one nerve’s presynaptic cell and the postsynaptic cell of the other nerve. This gap is called the synapse. The presynaptic cell has vesicles that store neurotransmitters. The floating neurotransmitters attach to the postsynaptic cell receptors when they are released by the presynaptic cells.

Neurotransmitters deficiency symptoms

The communication between nerves occurs when the brain sends an electrical signal. This signal is called the “action potential”. When this action potential reaches the end of a nerve, it triggers the presynaptic cell to release neurotransmitters that attach to the receptors on the postsynaptic cell.

Once these neurotransmitters attach to the receptors, the postsynaptic cell will reach a threshold and fire an action potential to the next cell. In this way, the spread of neurotransmitters continues until saturation occurs.

In brief:

  1. A neuron sends an electrical stimulus (action potential) to another neuron.
  2. The stimulus comes at the end of the (“presynaptic”) neuron.
  3. Vesicles are containing stored neurotransmitters.
  4. The electrical impulse triggers several reactions.
  5. The neurotransmitter vesicles fuse with the outer edge of the end of the neuron.
  6. The neurotransmitters end up in the synapse between two neurons, where they transmit the signal.
  7. The neurotransmitters travel to the beginning of the postsynaptic neuron, where they temporarily bind to a receptor. The temporary nature is important here because otherwise, the brain would be in a permanently active state.
  8. An electrical stimulus is then sent through again, whereby the neurotransmitters are removed and cleared by enzymes (see next section) or are reabsorbed.

Neurotransmitters regulation

Of course, some mechanism must keep the nerve cells from remaining in a permanently active state. That’s where enzymes come in, such as monoamine oxidase (MAO) and catechol-o-methyl transferase (COMT). These enzymes destroy the neurotransmitters that have attached to the receptors at a threshold. The vesicles reabsorb other neurotransmitters on the presynaptic cell. Consider, for example, the medication group SSRIs (Selective serotonin reuptake inhibitors). This medication prevents serotonin from being reabsorbed, thereby increasing the signal strength of serotonin.

This neurochemical process can be disrupted by genetic causes, medication, nutritional deficiencies, or illness. Problems with the MOA or COMT enzymes’ functioning, reduced receptor sensitivity, or a disturbed (too low or too high) reuptake can contribute to imbalances in the neurotransmitter profile.

The main neurotransmitters we are discussing in this article are:

  • Dopamine
  • Serotonin
  • Gamma Aminobutyric Acid (GABA)
  • Acetylcholine

Symptoms of neurotransmitters imbalance

Low levels of neurotransmitters cause unique symptoms and are generally quite easily traced to specific deficiencies. Below the mentioned neurotransmitters are discussed separately. We walk you through both the issues and symptoms of deficiencies and an excess of these neurotransmitters.


Dopamine is an important neurotransmitter that is especially known to people with AD(H)D. People with Parkinson’s disease also have low dopamine levels. An excess of this signal substance is found in people with schizophrenia. Dopamine is mainly associated with motivation and performance but also with sensitivity for addiction.

What Are Low Dopamine Symptoms?

  • Feelings of hopelessness or fear
  • Poor self-image / low self-esteem
  • Lack of motivation (to start tasks)
  • Impatience for small setbacks
  • Low-stress resistance
  • Short fuse and irritable under stress
  • Weight gain, often as a result of emotional eating

NOTE: The questions below are not a complete medical checklist. Obviously, a diagnosis must always be made by a doctor. The questionnaires, also for the other neurotransmitters, only serve as an indication, with which one can turn to a treating doctor or psychiatrist.

Dopamine deficiency questionnaire

If you can answer “yes” to the following questions, it may indicate a dopamine deficiency. The more often you can answer yes, the more this can indicate a dopamine deficiency.

  • Do you smoke, drink, or use stimulants? (drugs, energy drinks, lots of coffee) Y / N
  • Has your body weight increased since you were in your early 20s? Y / N
  • Do you find it difficult to start and/or complete tasks despite having enough energy? Y / N
  • Do you have a low libido? Y / N
  • Are you an emotional eater? Y / N
  • Do you have concentration problems? Y / N
  • Are you irritable? Y / N
  • Do you gamble, watch porn, use drugs, drink lots of alcohol? Y / N
  • Do you suffer from stiff joints? Y / N
  • Do you regularly suffer from cramps, spasms, or trembling muscles? Y / N
  • Do you often suffer from acid regurgitation? Y / N
  • Do you have trouble falling asleep? Y / N
  • Do you often have energy left in the evening and have problems starting up in the morning? Y / N
  • Do you often have mood swings? Y / N
  • Do you quickly feel taken aback? Y / N

Although a dopamine deficiency is significantly more common than an excess of dopamine, confusion can nevertheless arise, as many of the listed symptoms also apply to an excess of dopamine. For that reason, it is difficult to make a diagnosis based on the above questions, and a more extensive questionnaire is necessary to gain a good insight into the symptoms. Although high dopamine is quite rare, it can occur and cause symptoms of paranoia and schizophrenia. The most common symptoms of high dopamine are:

  • High libido
  • Paranoia
  • Manic feelings
  • An indomitable desire for satisfaction, including sexual promiscuity or adrenaline activities
  • Hyperfocus
  • Feeling that others are working in slow motion
  • Restlessness
  • Short fuse
  • Hyperactivity
  • Tension


Serotonin is the neurotransmitter most commonly associated with emotion and mood. Low serotonin is often considered the culprit in depression and social anxiety disorders. High serotonin is also known as Serotonin Syndrome and can be life-threatening. Serotonin syndrome can occur with the use of drugs (MDMA) or the use of serotonin stimulant supplements or medications.

Serotonin is also heavily involved in our perception of reality. This clarifies why hallucinogenic supplements and psychedelic drugs affect the serotonin balance and change our perception of the world around us.

What Are Low Serotonin Symptoms?

  • Feelings of unhappiness, dissatisfaction, apathy, frustration, or anger
  • Feelings of depression
  • Loss of pleasure in activities you normally enjoy doing
  • Difficulty staying positive
  • Aggressive feelings
  • Get emotional quickly
  • Little emotional resilience
  • Impulsive behavior
  • Poor memory
  • Dejection on dark, gray days
  • Not being able to enjoy relationships or less, resulting in self-isolation
  • Sleeping problems, such as difficulty falling asleep or staying asleep

In addition to these serotonin deficiency symptoms, there are also psychological conditions strongly related to serotonin deficiency, such as:

  • Eating disorders
  • Compulsive disorders
  • Panic attacks
  • PTSD (post-traumatic stress disorder)
  • Social phobia

Serotonin Deficiency Questionnaire

If you can answer “yes” to the following questions, it may indicate a serotonin deficiency. The more often you can answer yes, the more this can indicate a serotonin deficiency.

  • Do you have sleeping problems? Y / N
  • Do you often have the urge to eat when you are actually not hungry? Y / N
  • Have you stopped enjoying activities that you previously enjoyed intensely? Y / N
  • Are you less adventurous than before? Y / N
  • Do you have trouble making decisions and spend a long time deliberating? Y / N
  • Do negative thoughts and feelings keep running through your mind? Y / N
  • Do you find it difficult to deal with conflicts and times of crisis? Y / N
  • Do you turn small problems into “life-threatening” situations? Y / N
  • Do you ever think about suicide? Y / N
  • Do you regularly receive feedback from your environment about your negativity and moodiness or that you are difficult to deal with? Y / N
  • Do you feel that you are constantly in survival mode and not enjoying life to the fullest? Y / N

Although low serotonin is more common, high serotonin can manifest itself with drug abuse or over-supplementation of serotonin stimulant supplements. Serotonin syndrome symptoms are:

  • Dilated pupils
  • Muscle stiffness
  • Rapid heartbeat and high blood pressure
  • Agitation
  • Unrest
  • Diarrhea
  • Loss of coordination
  • Muscle twitches or spasms
  • Vomit

Serotonin syndrome can be life-threatening, so if an overdose occurs, it is imperative to go to the emergency room or call an ambulance and state the cause (drugs or supplementation).

Gamma Aminobutyric Acid (GABA)

Gamma-aminobutyric acid, or GABA, is the neurotransmitter responsible for calming the nervous system and regulating the stimulant effects of norepinephrine. You can see GABA as a nightcap for the nervous system. Healthy GABA levels bring calm to the nervous system, while low GABA causes agitation and, in extreme cases, can underlie panic disorders.

What Are Low GABA Symptoms?

  • Be scared easily
  • Out-of-body feelings
  • Difficulty breathing or shortness of breath
  • Sweaty hands
  • Cold hands and feet
  • Worrying excessively
  • Always take worst-case scenarios into account
  • Feeling overwhelmed easily
  • Busy mind
  • Headache
  • Compulsive acts / thoughts
  • Unexplained feelings of stress, panic, and anxiety
  • Feelings of fear or doom
  • Fast or irregular heartbeat
  • Muscle tension
  • Difficulty turning off thoughts
  • Difficulty focusing
  • Depersonalization and feelings that you are not living in reality, as if you see yourself in a movie.

GABA deficiency questionnaire

If you can answer “yes” to the following questions, it may indicate a GABA deficiency. The more often you can answer yes, the more this can indicate a GABA deficiency.

  • Do you experience panic attacks or sudden, inexplicable periods when you feel overwhelmed? Y / N
  • Do you (sometimes) feel “detached from reality”? As if you seem to be observing yourself and have stepped out of your body? Y / N
  • Do you have the feeling that you are “burned out” and that you just cannot recover from it? Y / N
  • Do you have trouble relaxing, and do you feel like you are constantly under stress? Y / N
  • Do you experience stiffness or (muscle) pain even though you don’t exercise or move much? Y / N
  • Does your heart ever skip a beat, or does it ever feel like there are less powerful heartbeats in between? Y / N
  • Is your breathing often high on your chest, and does it regularly seem that you are short of breath? Y / N

Too much GABA occurs sporadically in practice. Probably the symptoms will be the opposite of the previously mentioned symptoms of GABA deficiency. So this means a complete lack of fear, but also of motivation. The bottom line is that someone with too much GABA would almost do nothing doesn’t worry about anything, and hangs around with little emotion all day long.


Acetylcholine is one of the neurotransmitters that are heavily involved in brain functions in the prefrontal cortex or the part of the brain that distinguishes us, humans, from animals. Acetylcholine plays an important role in the function of working memory, learning, memory, creativity, and navigation.

What Are Low Acetylcholine Symptoms?

  • Poor memory, both visual, verbal, cognitive, and auditory
  • Reduced creativity
  • Bad word recall and loss of understanding
  • Difficulty mental thinking power
  • Difficulty recognizing faces and locations
  • Slow mental response
  • Bad spatial orientation or clumsiness
  • Difficulty navigating or using directions while driving

Acetylcholine Deficiency Questionnaire

If you can answer “yes” to the following questions, it may indicate an acetylcholine deficiency. The more often you can answer yes, the more this can indicate an acetylcholine deficiency.

  • Do you regularly hear from others that you are distracted? Y / N
  • Do you suffer from hair loss? Y / N
  • Do you constantly need lists because otherwise, you will forget everything? Y / N
  • Is your organizational talent not great? Y / N
  • Do you feel that your brain is no longer working as well as it used to? Y / N
  • Has your memory deteriorated? Y / N
  • Do you find it difficult to remember phone numbers and addresses? Y / N
  • Does Alzheimer’s or dementia run in your family? Y / N
  • Do you regularly forget your wallet or keys or where you have left something? Y / N
  • Do you have trouble with spatial insight? Y / N
  • Do you walk by your own family members at the supermarket because you did not recognize them? Y / N
  • Do you have trouble remembering faces or locations? Y / N

The neurotransmitters acetylcholine and serotonin maintain a close balance with each other. The symptoms of too high acetylcholine can be similar to the symptoms of too low serotonin, as they balance each other. Too high acetylcholine mainly causes the inhibition of other neurotransmitters. Read more about acetylcholine.

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