Hypothyroidism, also known as underactive thyroid, is a condition where the thyroid gland does not produce enough thyroid hormones. Thyroid hormones play a crucial role in regulating metabolism, growth, and development. Not having enough thyroid hormones can impact the body in many ways, including mentally.
Can hypothyroidism cause depression?
Yes, hypothyroidism can lead to depressive symptoms. Thyroid hormones affect the production of serotonin, dopamine, and norepinephrine, which are neurotransmitters that regulate mood. When thyroid hormone levels are low, it can disrupt the balance of these brain chemicals and lead to depression.
Some studies have found that over half of people with hypothyroidism experience depression. The severity can range from mild to debilitating. Symptoms of hypothyroidism-related depression include:
- Feelings of sadness, emptiness, or hopelessness
- Tiredness and lack of energy
- Sleep disturbances
- Changes in appetite and weight
- Difficulty concentrating
- Lack of interest in activities
- Feelings of worthlessness or guilt
- Suicidal thoughts
Treating the underlying thyroid imbalance with medications like levothyroxine can often resolve depressive symptoms. But some people may need additional antidepressant medication or psychotherapy.
Can hypothyroidism cause anxiety?
Hypothyroidism has also been linked to increased anxiety. One study found that 13% of people with hypothyroidism met the criteria for an anxiety disorder. The most common anxiety disorders seen were generalized anxiety disorder, panic disorder, and phobias.
It’s believed that thyroid hormones help regulate levels of norepinephrine, the neurotransmitter involved in the body’s “fight-or-flight” stress response. Low thyroid hormone disrupts norepinephrine signaling and can lead to heightened, persistent anxiety. Anxiety signs with hypothyroidism include:
- Feeling tense, on-edge, or restless
- Irrational worrying
- Panic attacks
- Fear or avoidance of certain places or situations
- Obsessive thought patterns
- Sleep issues from anxiety
As with depression, treating the thyroid deficiency with thyroid medication can often resolve anxiety. Cognitive behavioral therapy and anti-anxiety medication are also helpful for some people.
Can hypothyroidism cause brain fog and memory problems?
Yes, brain fog and memory issues are very common with hypothyroidism. Low thyroid hormones reduce blood flow and glucose metabolism in the brain, which impairs concentration, cognitive performance, and memory recall.
Studies show that people with hypothyroidism score worse on verbal memory tests and have slower processing speed compared to healthy controls. The Cognitive Impairment Rating Scale for hypothyroidism identified the following cognitive problems:
- Forgetfulness
- Difficulty finding words
- Feeling mentally “foggy”
- Trouble focusing and paying attention
- Taking longer to think or respond
- Impaired short-term memory
Again, treating the thyroid imbalance can reverse these effects in most cases. But some people continue to experience residual “brain fog” even after thyroid treatment. Strategies like reducing stress, getting good sleep, eating a healthy diet, and exercising can all help optimize brain function.
Can hypothyroidism make you irritable?
Moodiness, irritability, and impatience are common symptoms of hypothyroidism. One study found that up to 60% of people with hypothyroidism self-reported being more irritable.
It’s thought that thyroid hormone deficiency alters brain chemicals like serotonin and dopamine, making people more prone to mood swings and irritability. The fatigue, pain, and cognitive problems from hypothyroidism can also shorten one’s fuse.
Getting thyroid levels regulated with medication can improve irritability. Relaxation techniques, stress management, and psychotherapy may also help manage this symptom.
Can hypothyroidism increase your risk for bipolar disorder?
There does appear to be an association between hypothyroidism and increased risk of bipolar disorder, though more research is needed.
One study found bipolar disorder in 13.4% of people with hypothyroidism compared to just 2.4% of people without thyroid imbalance. The mood swings and depression of bipolar disorder are thought to stem from thyroid hormone effects on neurotransmitters and hormones that regulate our circadian rhythm and sleep-wake cycles.
However, it’s not a simple cause and effect. While thyroid issues may predispose someone to bipolar disorder, other genetic and environmental factors are likely involved. More research is needed to clarify the relationship between thyroid function and bipolar risk and symptoms.
Can hypothyroidism increase autism risk in babies?
There is conflicting evidence about whether maternal hypothyroidism during pregnancy raises autism risk in infants. Some studies have found an association:
- A 2013 study found the risk of autism doubled in children whose mothers had hypothyroidism in pregnancy.
- Another large study in 2017 found the risk of autism spectrum disorders was higher among children whose mothers had hypothyroidism before pregnancy.
However, other studies have not found a link between pregnancy thyroid levels and autism. More research is needed to confirm whether untreated hypothyroidism affects fetal brain development and autism risk.
Doctors recommend testing and correcting thyroid deficiency before or in early pregnancy to ensure normal fetal neurodevelopment.
Can hypothyroidism cause psychosis?
In very rare cases, severe untreated hypothyroidism can trigger a temporary psychotic episode. This is an extremely uncommon manifestation known as myxedema madness.
Symptoms may include hallucinations, delusions, paranoia, confusion, and manic behavior. It is thought to result from critical thyroid hormone deficiency impacting the brain. Treatment involves rapidly correcting the thyroid imbalance with medications.
Myxedema madness is estimated to occur in only 0.2% of hypothyroid cases. It is most likely to happen in older individuals with long-standing, undiagnosed hypothyroidism. Most people with routine hypothyroidism in modern times will never experience myxedema madness.
Can hypothyroidism increase risk of dementia?
There is conflicting evidence about whether hypothyroidism is linked to a higher risk of dementia, including Alzheimer’s disease. Some studies have found correlations:
- A 2019 study found hypothyroidism was associated with a 40% increased risk of dementia in older adults.
- One theory is that thyroid hormone deficiencies cause abnormalities in amyloid protein that accumulates in Alzheimer’s disease.
- An animal study showed hypothyroidism accelerated amyloid plaque formation.
However, other large, long-term studies have not found hypothyroidism to be a clear risk factor for dementia. More research is needed to elucidate the potential effects of thyroid dysfunction on different forms of dementia.
Can hypothyroidism cause mental impairment in babies?
Yes, hypothyroidism in newborn infants can lead to severe mental and physical developmental delays if not treated promptly. This condition is called cretinism.
Thyroid hormones are critical for brain maturation in babies. Congenital hypothyroidism, if undiagnosed, can result in:
- Impaired motor skills and muscle tone
- Learning disabilities and mental retardation
- Delayed speech, language, and cognitive skills
- Stunted growth
- Abnormal facial features and skeletal development
Fortunately, routine newborn screening for hypothyroidism enables early treatment and can prevent cretinism. Babies diagnosed with congenital hypothyroidism can have normal cognitive development with thyroid hormone therapy started within 2-3 weeks after birth.
Can hypothyroidism increase risk of schizophrenia?
links between hypothyroidism and schizophrenia are unclear. Some studies have suggested an increased risk:
- A Danish study found a 3-fold higher rate of schizophrenia spectrum disorders in people hospitalized for hypothyroidism.
- Autopsy studies show thyroid abnormalities in some schizophrenia cases.
- Dopamine dysfunction seen in schizophrenia may be linked to thyroid effects on growth hormones.
However, many studies have not found a definitive causative relationship between hypothyroidism and schizophrenia. More research is needed to clarify if thyroid imbalance is an actual risk factor for this mental illness.
Can hypothyroidism cause personality changes?
The thyroid hormones triiodothyronine (T3) and thyroxine (T4) impact nearly every cell and system within the body. Deficiencies in these hormones can certainly lead to noticeable changes in energy, cognition, emotions, and daily functioning – essentially, one’s “personality.”
Specifically, untreated hypothyroidism can transform someone into a “sluggish,” fatigued, unfocused, and irritable version of themselves. They may withdrawal socially and seem depressed. Once their thyroid levels normalize, their personality, mood, motivation, and acuity bounce back.
However, prolonged, undiagnosed hypothyroidism over many years may result in persistent personality changes. This highlights the importance of recognizing symptoms early and treating appropriately.
In summary:
Hypothyroidism has wide-ranging mental effects that stem from thyroid hormones’ impact on brain function, development, blood flow, and neurotransmitters. Common effects include:
- Depression
- Anxiety
- Brain fog, poor memory, and concentration problems
- Irritability and moodiness
- Altered personality
Rare but serious manifestations like myxedema madness and cretinism may occur with severe cases. Many mental effects resolve with appropriate thyroid hormone replacement. But some residual symptoms can remain even after treatment.
While links to bipolar disorder, schizophrenia, dementia, and autism have been proposed, more research is needed to clarify if thyroid dysfunction is a definite risk factor for these conditions.
Overall, the far-reaching influence of these small gland hormones underscores the importance of recognizing hypothyroidism early and managing it properly to minimize adverse mental health effects.