Difficulty concentrating

Serotonin

Serotonin plays a key role in cognitive function, memory, and focus. Low serotonin levels are often linked to difficulty concentrating, brain fog, and mental fatigue.

How Serotonin Affects Concentration

• Regulates Mood and Mental Clarity

Serotonin helps stabilize mood, reduce anxiety, and improve focus.

Low serotonin can cause brain fog, irritability, and difficulty organizing thoughts.

Supports Healthy Sleep (Which Affects Focus)

• Serotonin works with dopamine and norepinephrine, which are crucial for attention, learning, and memory.

• Low serotonin can disrupt these pathways, making it hard to stay focused or remember details.

Causes of Low Serotonin and Poor Concentration

• Chronic stress → Increases cortisol, which depletes serotonin.

• Poor gut health → 90% of serotonin is made in the gut, and conditions like IBS-D can reduce serotonin production.

• Nutrient deficiencies → Low B vitamins, magnesium, and tryptophan affect serotonin synthesis.

• Lack of sunlight → Reduces natural serotonin production.

• Poor sleep patterns → Serotonin helps regulate sleep, and sleep deprivation worsens focus.

Noradrenaline

Noradrenaline (norepinephrine) is one of the brain’s key chemicals for attention, mental clarity, and sustained focus. When it's out of balance—either too low or too high—it can lead to significant difficulty concentrating, mental fog, and distractibility.

In an optimal state, noradrenaline helps activate the prefrontal cortex, the brain region responsible for executive functions like planning, decision-making, and maintaining attention. It gives your brain the alertness and stimulation it needs to stay on task. But when noradrenaline levels are too low (often seen in depression, burnout, or inattentive-type ADHD), the brain can feel sluggish, unmotivated, and unable to “lock in” on tasks. You might find yourself zoning out, easily distracted, or unable to organize thoughts mentally.

On the flip side, when noradrenaline is too high (such as during anxiety or chronic stress), it can cause mental overload. Thoughts race, the mind jumps from one idea to the next, and it becomes hard to concentrate because the brain is too stimulated. This is why people under stress often struggle to focus, despite being alert.

Struggling to focus, think clearly, or retain information? It might not be just fatigue or distraction—your hormones play a huge role in cognitive clarity.

Adrenaline

sharpens attention during short-term stress, but when it's constantly elevated, it overwhelms the brain with excessive stimulation. This leads to scattered thoughts, a racing mind, and difficulty filtering distractions, making it hard to focus on one task at a time.

GABA (Gamma-aminobutyric acid)

GABA is a calming neurotransmitter that helps regulate neural activity. Low GABA levels leave the brain in a hyperactive, anxious state, which makes it difficult to slow down, think clearly, or stay present. GABA deficiency is a common driver behind brain fog and overstimulation.

DHEA (Dehydroepiandrosterone)

DHEA supports memory, mood, and mental performance. When DHEA is low, you may experience mental fatigue, low motivation, and poor stress resilience, all of which impair concentration. It also helps buffer the negative effects of high cortisol on brain function.

Cortisol

Cortisol, when balanced, supports alertness, but chronic elevation or burnout from long-term stress can disrupt brain function. High cortisol leads to mental cloudiness and forgetfulness, while low cortisol contributes to fatigue and sluggish thinking. Either imbalance can significantly reduce your focus.

Glutamate

When Glutamate Is Dysregulated:

Too much glutamate causes neuronal overactivation, which can:

• Impair prefrontal cortex function (the part of the brain responsible for attention, decision-making, and organization)

• Lead to mental noise, racing thoughts, or scattered attention

• Cause neurofatigue, where the brain tires quickly and loses clarity

Too little glutamate in key circuits can also blunt mental energy and reduce alertness, creating brain fog or a “zoned out” feeling.

Glutamate & Cognitive Strain:

Elevated or erratic glutamate signaling is linked to attention difficulties seen in:

• ADHD

• Burnout

• Chronic fatigue syndrome

• Long-term stress and anxiety

Glutamate overload affects synaptic plasticity, making it harder for the brain to filter distractions and maintain focus.

The Glutamate-Focus Loop:

• Chronic stress or inflammation → disrupts glutamate balance

• Disrupted glutamate → weakens concentration and mental endurance

• Poor focus → increases frustration/stress, which worsens glutamate imbalance