The thyroid is a small, butterfly-shaped gland located in the lower part of your neck and plays a vital role in keeping your brain and body healthy. The thyroid gland has a powerful influence on the brain because it controls the production of many neurotransmitters, such as acetylcholine, dopamine, GABA, and serotonin. It also regulates your metabolism. Problems occur when thyroid dysfunction causes the gland to become underactive and produce too little hormone (hypothyroidism) or become overactive and make an excessive amount of hormone (hyperthyroidism).

Hypothyroidism: Brain SPECT scans of people with untreated hypothyroidism show overall decreased brain activity, which often leads to depression, cognitive problems, and anxiety.

Hyperthyroidism: When the thyroid is overactive it makes everything in your body work too fast, causing you to feel jittery and edgy, as though you’ve had way too much caffeine.

Common Symptoms of Thyroid Dysfunction:

Hypothyroidism:

• Attentional problems

• Brain fog

• Depression

• Difficulty concentrating

• Dry skin and hair

• Fatigue

• Hair loss

• Memory problems

• Psychosis

• Sensitivity to cold temperatures

Hyperthyroidism:

• Anxiety/feeling jittery

• Breathlessness/fast pulse

• Depression

• Difficulty concentrating

• Fatigue

• Feeling overheated

• Irritability

• Mania

• Memory problems

• Psychosis

• Racing thoughts

• Sleeplessness, restlessness

• Weight loss despite increased appetite

Estrogen is one of the primary hormones involved in a woman’s menstrual cycle. Males also make and need estrogen—although to a lesser degree. When estrogen levels are healthy and balanced, it helps optimize neurotransmitter production and brain function, but when levels are off, it can cause all sorts of problems.

Estrogen dominance is a condition in which there is too much estrogen relative to the amount of progesterone. When this happens, the gentle monthly fluctuation of hormones turns into a series of intense spikes and dramatic drop-offs that disrupt important brain processes and make you moody, anxious, and irritable. In women, estrogen dominance often occurs during the transition into perimenopause, while in aging men, estrogen dominance can emerge as testosterone levels decline.

Low estrogen levels can make you feel depressed and have trouble focusing and thinking. These problems can worsen during perimenopause when estrogen levels can fluctuate wildly and during menopause when the hormone drops and stays low. Brain SPECT images show that as estrogen levels go down, blood flow in the brain also decreases.

Common Symptoms of Estrogen Imbalances:

Estrogen Dominance:

• Bloating

• Carbohydrate cravings

• Depression, moodiness

• Fatigue

• Fibrocystic breasts

• Headaches or migraines

• Heavy bleeding

• Low libido

• Memory loss, brain fog

• Sleep disturbances

• Sluggish metabolism

• Thyroid dysfunction

• Vaginal or oral yeast (thrush)

• Weight gain, especially in the belly and hips

Low Estrogen:

• Aches and pains

• Brain fog

• Concentration problems

• Depression, crying spells, mood changes

• Fatigue

• Heart palpitations

• Hot flashes

• Memory loss

• Osteoporosis

• Painful intercourse

• Sleep disturbances

• Urinary incontinence, bladder infections

• Weight gain

Progesterone: Nature’s Anti-Anxiety Hormone

Progesterone is the other major hormone in a woman’s monthly cycle. It is a natural anti-anxiety hormone that helps you feel calm, settled, and peaceful. It also stimulates the repair and growth of the brain’s myelin sheath, which insulates nerve fibers and neurons. When progesterone and estrogen are out of balance or when this relaxation hormone drops too dramatically, calmness can give way to irritability, anxiety, depression, sleepless nights, and brain fog. For some women, when progesterone and estrogen levels drop prior to monthly menstruation, mood stability goes out the window.

Common Symptoms of Low Progesterone:

• Anxiety

• Bone loss

• Depression

• Fibrocystic breasts

• Mental fogginess

• Postpartum depression

• PMS

• Premenstrual headaches

• Trouble sleeping

Testosterone is commonly associated with maleness because it is responsible for the facial hair, deep voice, muscle strength, and other characteristics we observe in men. Women also need and produce small amounts of testosterone; however, high testosterone levels in women can cause aggression, moodiness, acne/oily skin, and anger outbursts.

In both men and women, healthy amounts of testosterone help protect the brain and nervous system, thus keeping problems like depression, cognitive impairment, and Alzheimer’s disease at bay. As men get older, some can develop abnormally low levels of testosterone that adversely affect their brain and body.

Common Symptoms of Low Testosterone:

• Anxiety

• Depression

• Difficulty concentrating

• Erectile problems

• Fatigue

• Increased body fat/reduced lean muscle

• Hair loss

• Hot flashes

• Lack of motivation

• Low bone density

• Low libido

• Moodiness

• Trouble sleeping

The adrenal glands are part of what is called the HPA (hypothalamic-pituitary-adrenal) axis, which controls how your body reacts to stress. When faced with a stressful situation, your adrenal glands release a cascade of hormones, including adrenaline, DHEA, and cortisol as part of your “fight-or-flight response.” Once the threat has passed, your body processes normalize—your heartbeat and breathing slow to their usual rate, your muscles relax, and your adrenals turn off production of those hormones until they are needed again.

In cases where stress becomes chronic, there can be a seemingly constant flow of stress hormones, that in turn, overwhelm your body and contribute to brain health/mental health issues. Chronically high cortisol levels also cause your blood sugar and insulin levels to spike. This can lead to harmful changes in the brain, including a drop in the calming neurotransmitter serotonin. High levels of cortisol are linked to mental health conditions, such as anxiety, depression, and PTSD.

In the brain, chronic stress produces more white matter and fewer neurons (gray matter) than normal, skewing their balance and disrupting communication within the brain.

Common Signs of Adrenal Fatigue:

• Abdominal fat that doesn’t go away, no matter what you do

• Brain fog and difficulty concentrating

• Craving for sweets or salty foods

• Decreased stress tolerance

• Dizziness when getting up from a seated or prone position

• High blood pressure and rapid heartbeat

• Low sex drive

• Lowered resistance to infection

• Memory problems

• Morning and afternoon fatigue, lack of stamina

• Poor wound healing

• Signs of premature aging

Insulin is a hormone that helps regulate your blood sugar levels. All the cells in your body need sugar (glucose) for energy, but they can’t absorb it directly from your bloodstream. To facilitate this, insulin is released by the pancreas after you eat carbohydrates and acts like a key that unlocks cell membranes so glucose molecules can enter the cells to give them the energy they need. After you have eaten, any excess glucose gets shuttled to your liver for storage and then slowly released back into your bloodstream as insulin levels go back down.

However, persistent high levels of sugar in your bloodstream can eventually lead to a host of medical problems, including fatty liver disease. High insulin levels can also prevent the breakdown and flushing of dietary fat from the body, leading to increased fat storage and weight problems. One of the main consequences of chronically eating a high-sugar diet and obesity is a decrease in insulin’s ability to regulate your blood sugar, which can lead to pre-diabetes and diabetes.

When you eat refined carbohydrate foods and other forms of sugar your blood sugar levels spike and then crash. This rollercoaster effect can impact your moods and mental wellbeing.

Common Signs of Blood Sugar (Insulin) Issues:

• Addiction to sugar

• Anger

• Anxiety

• Depression

• Irritability

• Psychosis/delirium

• Trouble concentrating