Anxiety (Meier, 2019) – Is anxiety genetic?

Nebula Genomics DNA Report for Anxiety

Is anxiety genetic? We created a DNA report based on a study that attempted to answer this question. Below you can see a SAMPLE DNA report. To get your personalized DNA report, purchase our Whole Genome Sequencing!

A sample report on anxiety from Nebula Genomics
A sample report on anxiety genetic variants from Nebula Genomics

Additional Information

What is Anxiety? (Part 1 of Is anxiety genetic?)

Fear is a necessary and normal emotion, whose developmental origin lies in a protective fight-or-flight reaction.

On the other hand, anxiety is a health condition. It is a term for mental illness, or disorder, associated with excessive, exaggerated fear reactions in the absence of a real external threat. While most people feel anxious at some time in their life, an anxiety disorder does not go away and can get worse over time. Symptoms can interfere with daily activities such as work, school, and relationships.

There are three main forms of anxiety:

  • Generalized anxiety disorder (GAD) in which diffuse, nonspecific fears occur spontaneously and randomly and have no situation or object as a trigger.
  • Panic disorder that bring on panic attacks, sudden periods of intense fear 
  • Phobias that focus on concrete things and are tied to specific triggering objects, situations, or spaces (e.g., animals, people, or lack of space).

Epidemiology (Part 2 of Is anxiety genetic?)

The disorder is generally widespread. Prevalence ranges between 13.6% and 28.8% in Western countries. Comorbidity among individuals with an anxiety disorder is high: three out of four people also experience at least one other mental disorder in their lifetime.

In 2007, the National Institute of Mental Health reported an estimated 19.1% of all U.S. adults reported an anxiety issue in that year. 

Anxiety disorder prevalence in the world
Anxiety is most prevalent in North and South America and some countries in western Europe. Wikipedia. CCAttribution 3.0 Unported.

Symptoms (Part 3 of Is anxiety genetic?)

General symptoms of a person with an anxiety disorder include:

  • Headaches and chronic pain
  • Palpitations and pulse acceleration
  • Dizziness, sweating
  • Tremor or shaking
  • Dry mouth, flushing
  • Difficulty speaking, plus difficulty breathing, feeling of tightness or chest pain
  • Nausea, vomiting or diarrhea
  • Insomnia
  • Disturbances of consciousness, for example, the feeling of going crazy
  • Feeling that things are unreal or that you yourself are “not really there”
  • Feeling that one no longer has control over one’s own thoughts
  • Drowsiness, fear of dying, general feeling of annihilation
Anxiety symptoms
Anxiety can result in many physical symptoms including headaches, digestive issues, dizziness, and insomnia. Wikipedia. CCAttribution-Share Alike 4.0 International

These disorders have a high comorbidity – with each other, as well as with anxiety and depression, substance abuse disorders, and poor quality of life. There are several types of anxiety disorders.

Generalized anxiety disorders

These include persistent symptoms of anxiety that are also not limited to specific situations. A person may experience nervousness, trembling, muscle tension, sweating, drowsiness, palpitations, hyperventilation, difficulty swallowing, dizziness, upper abdominal discomfort, restlessness, difficulty concentrating, irritability, and difficulty falling asleep due to constant worry. These symptoms persist most days and cause problems with performing daily activities. 

Sufferers often do not know the triggers of their anxiety. For example, they may be tormented by the fear that they or their relatives might fall ill or suffer accidents.

Panic disorder

People who experience a panic attack may feel 

  • Heart palpitations, a pounding heartbeat, or an accelerated heart rate
  • Sweating
  • Trembling or shaking
  • Sensations of shortness of breath, smothering, or choking
  • Feelings of impending doom
  • Feelings of being out of control

People may become obsessed over avoiding panic attacks and make changes to their lives that involve removing triggers for such attacks. Worry over and effort to avoid panic attacks can assasperate the illness.  

Phobias

In specific phobias, anxiety is formed in relation to a specific object, situation, or place. There is significant emotional distress from the anxiety symptoms. The provoking objects or situations are avoided. At the same time, there is an understanding that the fears are exaggerated or unreasonable. 

There are very many possible phobias, as phobic reactions can be directed at virtually anything. Some better known specific phobias are:

  • Fear of spiders (arachnophobia).
  • Fear of dogs (kynophobia)
  • Fears of blood (blood phobia, hematophobia)
  • Fears of confined spaces (claustrophobia)
  • Fears of high altitudes (acrophobia)
  • Fear of flying (fear of flying, aviophobia)
  • Fear of urinating in public toilets (paruresis), see also below under “Social phobia”.
  • Fear of the dentist (dental phobia)
  • Fear of dark rooms (achluophobia)

Other classifications include agoraphobia, anxiety disorder due to a medical condition, selective mutism, separation anxiety disorder, social anxiety disorder (social phobia that appears in social situations), and substance-induced anxiety disorder.

Causes (Part 4 of Is anxiety genetic?)

As with most mental disorders, there is as yet no conclusive knowledge about the causes of anxiety. At present, a large number of causative or triggering factors are assumed, which in combination cause the actual onset of a disorder. 

A combination of both genetic predisposition and environmental factors are thought to contribute to the combination of triggers. 

Is anxiety genetic?

There is evidence that genetics play a role in the risk of developing anxiety. Family and twin studies showed that about 30% of anxiety cases run in families. Genetic studies provided diverse evidence for the involvement of gene abnormalities in the serotonin, dopamine, norepinephrine, and epinephrine neurotransmitters, specifically genetic risks associated with the genes 5-HTT, 5-HT1A, and MAOA.

5-HTT

5-HTT is a protein that transports the neurotransmitter, serotonin, from synaptic spaces into presynaptic neurons. These proteins influence the onset of several psychiatric disorders. Variants of this gene are especially associated with depression and some variants are even known as the “depression gene”.

5-HT1A

5-HT1A is a serotonin receptor. Activation of this receptor has been involved in the mechanism of action of anxiolytic, antidepressant and antipsychotic medications. Activation of 5-HT1A in the pre-synaptic region controls serotonin feedback. Negative feedback from this protein may increase serotonin which may lead to increased anxiety-related behavior.

MAOA

The MAOA gene codes for an enzyme called monoamine oxidase A. This enzyme breaks down the neurotransmitters serotonin, epinephrine, norepinephrine, and dopamine, through oxidation.

Neuroanatomy

A 2014 study showed that people with anxiety showed aberrant activity in the prefrontal cortex and amygdala, as well as decreased signaling between these areas. At the same time, the volume of both regions was increased, but the anatomical connections between them were decreased.

Neuroanatomy of the brain of someone with anxiety
Improper activation of and communication between the prefrontal cortex and amygdala are thought to contribute to the development of anxiety. Wikipedia. CCAttribution-Share Alike 4.0 International

In social phobia, treatment successes, regardless of the type of therapy, showed changes in activity and signaling traffic of the amygdala toward normalization.

Neurochemistry

The neurochemistry of anxiety disorders primarily involves the following neurotransmitter systems:

  • Serotonin
  • Norepinephrine
  • Dopamine
  • GABA
  • various neuropeptides
  • glutamate
  • Thyroid dysfunction

There is also evidence that both hyper– and hypothyroidism of the thyroid gland may be risk factors for the disorders in rare cases.

Medical causes

Examples of medical problems that can be linked to anxiety include:

  • Heart disease
  • Diabetes
  • Thyroid problems, such as hyperthyroidism
  • Respiratory disorders, such as chronic obstructive pulmonary disease (COPD) and asthma
  • Drug misuse or withdrawal
  • Withdrawal from alcohol, anti-anxiety medications (benzodiazepines) or other medications
  • Chronic pain or irritable bowel syndrome
  • Rare tumors that produce certain fight-or-flight hormones

Sometimes the disorder can also be a side effect of certain medications.

It’s more probable that anxiety is linked to a medical cause if you don’t have a family members with the disorder or a personal history of the disorder.

Other factors

These factors may increase your risk of developing an anxiety disorder:

  • Trauma
  • Stress due to an illness
  • Stress buildup due to stressful life experiences or life events
  • Personality
  • Other mental health disorders
  • Family history
  • Drugs or alcohol

Diagnosis (Part 5 of Is anxiety genetic?)

If medical conditions are ruled out as the cause for symptoms, a medical provider may refer a patient to a psychiatrist that specializes in diagnosing and treating mental disorders.

The focus of diagnosis is the psychological evaluation. This often  involves discussing thoughts, feelings and behavior. Some psychiatrists compare your symptoms with diagnosis criteria from the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Based on the evaluation, the psychiatrist can make an initial diagnosis.

The following criteria are indicative of an anxiety disorder:

  • The anxiety is recognizably inappropriate to the situation.
  • The corresponding anxiety reactions last significantly longer than necessary.
  • The particular type of anxiety can neither be explained, influenced nor managed by the affected person.
  • The fears lead to clear impairments of the life of the affected person.
  • The fears restrict contact with strangers.

Symptom scale questionnaires such as the Hamilton Anxiety Scale (HA-MA) are used to conduct severity assessments. 

Children who experience anxiety are diagnosed when they do not outgrow the fears and worries that are typical in young children, or when fear begins to interfere with daily activities. Symptoms in children often cause irritability and anger that may go undiagnosed until later in life.

Treatment (Part 6 of Is anxiety genetic?)

Treatment is focused on either cognitive behavioral therapy, medications, or a combination of both. 

Cognitive Behavioral Therapy

CBT teaches people different ways of thinking, behaving, and reacting to anxiety-producing and fearful objects and situations. Either cognitive or exposure therapy can be used in this sense. Cognitive therapy helps identify and neutralize thoughts that are causing anxiety while exposure therapy helps people confront fears that are driving the disorder. 

The triangle of cognitive behavioral therapy
Cognitive Behavioral Therapy involves discussing your thoughts, feelings, and behavior. Wikipedia. CCAttribution-Share Alike 3.0 Unported.

Medication

Medications can help relieve symptoms to treat anxiety. The most common classes of medications used are anti-anxiety drugs (such as benzodiazepines), antidepressants, and beta-blockers.

Anti-anxiety drugs: These are usually the first line treatment. They tend to work quicker than the other options. However, people can build up a tolerance to these medications, meaning that they will eventually have to take higher doses.  

Because of this drawback, medical providers often prescribe benzodiazepines for short periods of time and take people off the medication slowly so as to avoid withdrawal symptoms. 

Antidepressants: These medications, such as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), may help improve the way your brain uses certain chemicals that control mood or stress. However, it may take awhile to find the one that works best. Additionally, it takes longer for these medications to work. 

Beta-blockers: Although beta-blockers are most often used to treat high blood pressure, they can also help relieve physical symptoms, such as rapid heartbeat, shaking, trembling, and blushing. These medications are also used for short time periods and in “as needed” cases.

Prevention

There are several recommended approaches to help reduce symptoms for people with anxiety disorders and improve their quality of life.  

  • Get help early and joining a support group
  • Stay active
  • Avoid alcohol or drug use. Alcohol and drug use can cause or worsen anxiety

If you liked this article, you should check out our other posts in the Nebula Research Library! You may also interested in medication reviews such as for the antidepressants Lexapro and Zoloft.