Difficulty sleeping

Serotonin

Serotonin plays a crucial role in regulating sleep, mood, and relaxation. It is a precursor to melatonin, the hormone responsible for the sleep-wake cycle. Low serotonin levels can cause insomnia, restless sleep, and poor sleep quality.

How Serotonin Affects Sleep

• Serotonin Converts to Melatonin for Sleep Regulation

• During the day, serotonin helps with mood and focus.

• At night, the brain converts serotonin into melatonin, which signals the body to sleep.

• Low serotonin = Low melatonin = Poor sleep.

Serotonin Helps Relax the Nervous System

• Serotonin reduces stress and anxiety, helping the body enter a relaxed state for sleep.

• Low serotonin makes it harder to "switch off" at night, leading to racing thoughts and difficulty falling asleep.

Serotonin Influences REM Sleep (Deep Sleep Stage)

• Serotonin helps regulate the REM sleep cycle, which is essential for memory and brain function.

• Low serotonin can cause fragmented sleep, waking up frequently, and feeling unrefreshed in the morning.

Noradrenaline

Noradrenaline, also known as norepinephrine, is a neurotransmitter that plays a key role in the body’s stress response and in maintaining alertness and arousal. While it is essential for staying focused and responsive during the day, high levels of noradrenaline at night can interfere with the body’s ability to relax and initiate sleep. Normally, noradrenaline levels drop in the evening to allow the brain to transition into restful sleep. However, in individuals experiencing chronic stress, anxiety, or emotional overload, this decline doesn’t happen efficiently. As a result, the brain remains in a state of heightened alertness—often described as being "tired but wired"—making it difficult to fall asleep or stay asleep. Elevated noradrenaline activates the sympathetic nervous system, which can cause physical symptoms like a racing heart, muscle tension, and shallow breathing, all of which disrupt sleep. It also interferes with REM sleep, a critical stage for emotional processing and memory consolidation. This leads to poor sleep quality, frequent awakenings, and non-restorative rest.

Struggling to fall asleep, stay asleep, or wake up refreshed? Sleep issues aren’t always just about poor habits—they’re often tied to hormonal imbalances caused by stress, fatigue, and burnout. Your sleep-wake cycle, or circadian rhythm, is tightly regulated by key hormones and neurotransmitters.

Adrenaline (Epinephrine)

Adrenaline keeps you alert during stress. It’s designed to help the body respond quickly in emergencies. When adrenaline levels remain elevated into the evening (due to chronic stress or overthinking), the body struggles to “switch off.” This leads to racing thoughts, difficulty falling asleep, and frequent night-time awakenings. It’s the classic “tired but wired” feeling.

GABA (Gamma-aminobutyric acid)

GABA is the body’s main calming neurotransmitter. It helps the brain slow down, preparing the body for deep, restorative sleep. Low GABA makes it difficult to calm the mind and body before bed. This causes restlessness, light sleep, and difficulty staying asleep, leading to poor recovery and daytime fatigue.

DHEA (Dehydroepiandrosterone)

DHEA plays a protective role against stress and supports brain health and hormonal stability. Low DHEA is associated with poor sleep quality, especially in individuals under chronic stress or hormonal imbalance. It contributes to increased nighttime awakenings and reduces the body’s ability to handle stress during the night.

Cortisol

Cortisol follows a natural rhythm—rising in the morning to wake you up and lowering at night to allow sleep.

Low morning cortisol = hard to wake up, brain fog, and grogginess Chronic imbalance flattens this curve, leading to insomnia or unrefreshing sleep.

Glutamate

Glutamate is the brain’s main excitatory neurotransmitter—it activates neurons and supports thinking, memory, and learning.

How Glutamate Affects Sleep:

To fall asleep, the brain must shift into a calmer, inhibitory state, primarily driven by GABA (a calming neurotransmitter).

This makes it harder to:

• Fall asleep

• Stay asleep

• Reach deep, restorative sleep stages (especially slow-wave sleep)

The Vicious Cycle:

Poor sleep increases glutamate levels and reduces clearance, especially if glial cells aren’t functioning well.

More glutamate = More overstimulation, leading to:

• Racing thoughts at night

• Restless sleep

• Early waking with a wired-tired feeling

Research Insight:

• Studies using MR spectroscopy show elevated glutamate in the anterior cingulate cortex and thalamus in people with insomnia.

• People with chronic sleep deprivation also show signs of glutamate buildup, which impairs neuroplasticity and emotional regulation.