What Causes Depression and Anxiety?
Learn what causes depression and anxiety and the relationship between them in this comprehensive article.
Table of Contents
Understanding Depression and Anxiety
Depression and anxiety are two of the most commonly occurring mental disorders, with many individuals suffering from anxiety and depression. It is estimated that one in six American adults will have depression in their lifetime. 1
It is also estimated that 19.1% of the US adult population is struggling with an anxiety disorder. 2
The Relationship Between Anxiety and Depression
Anxiety and depression are related and are often co-occurring. Both anxiety and depression are internalizing disorders, and both share functional and structural brain alterations in pathways involving emotional regulation, executive functioning, and cognitive control. Anxiety and depression typically occur during development, with anxiety emerging during preadolescence and early adolescence. Depression occurs a little later in development, usually following anxiety, emerging during adolescence and early to mid-adulthood. So, can anxiety cause depression? The short answer is yes. The details of this relationship will be discussed throughout this article.
Why Are Anxiety and Depression Often Co-Occurring?
There is a strong link between anxiety and depression. A worldwide study of individuals with a lifetime history of major depressive disorder found that 45.7% also had a lifetime history of one or more anxiety disorders. 3
Anxiety and depression share several risk factors, including genetics, early life adversity, and current stress exposure. Understanding the causes is key to understanding anxiety and depression. Luckily, treatment efforts that target depression are beneficial treating anxiety and vice-versa.
Major Causes of Depression
Depression is a disorder characterized by long-lasting feelings of sadness that affect normal functioning. While depression may seem to come on suddenly, there are several risk factors for developing depression. 4
The major causes of depression will be detailed below.
Death or a Loss
Grief and loss, although natural causes, can increase the risk of depression. When grief is prolonged or leads to symptoms affecting life functioning, it can indicate depression.
One of the most widely accepted causes of depression is changes in brain chemistry. These changes are related explicitly to neurotransmitters dopamine, serotonin, and norepinephrine. Individuals with imbalances in these neurotransmitters can experience symptoms of depression.5
Abuse in childhood is a strong predictor of depression later in life. In a recent study of hospitalized individuals with depression, 75.6% of chronically depressed patients reported having a significant history of childhood trauma and abuse. Abuse in adulthood can also cause depression. 6
Hormonal imbalances can also cause depression. Hormones, specifically those related to the thyroid, can be factors in depression. Because of this, symptoms of depression are related to thyroid conditions. For women especially, conditions related to the menstrual cycle, which are hormonal in origin, can also cause depression. 7
Certain medical conditions can also be related to depression. Serious illness, thyroid conditions, cancer, chronic pain, heart disease, lupus, diabetes, HIV, and multiple sclerosis can increase the risk of depression. 8
Substance misuse, whether it be alcohol or other drugs, is related to the development of depression. Approximately 30% of individuals struggling with a substance use disorder also have clinical depression. Additionally, depression can be a side effect of withdrawal from several drugs.
Depression can also be a side effect of certain medications. For example, isotretinoin, an acne drug, can cause depression. This is also true of certain antiviral drugs and corticosteroids.
Depression is a heritable disease, meaning that it has a genetic component. Having a family history of depression can increase your risk. It is estimated that depression is moderately heritable, at 40%.
Major Causes of Anxiety
Feeling stressed and anxious from time to time is normal. However, for individuals with an anxiety disorder, the feelings of anxiety and worry are persistent and difficult to control. There are many triggers and causes of anxiety.
Stress at Work
Work stress can trigger anxiety. According to the 2021 Mind the Workplace report, 85% of respondents reported that job stress affected their mental health. Job stress can be due to keeping up with unrealistic demands, presenting, and interpersonal relationships. If the anxiety continues outside the workplace and is present on days off, it may indicate an anxiety disorder. 9
Stress from School
Similar to job stress, academic stress can trigger anxiety. Academic and peer-related pressure can cause stress for younger individuals. Additionally, anxiety is a disorder that appears in pre to mid-adolescence. If stress related to school is causing anxiety, and it doesn’t resolve when the individual is no longer in school, this may indicate an anxiety disorder.
Chemical imbalances have also been cited as the cause of anxiety. Anxiety is a disorder that affects neurotransmitters, including serotonin, norepinephrine, and gamma amino butyric acid. Individuals with anxiety typically show changes in the levels of these brain chemicals. 10
Financial stress can also trigger anxiety, especially if it’s long-term. Long-term stress is a risk factor for developing an anxiety disorder. Exposure to stress may weaken the part of the brain that controls coping or anxiety control. Stress also affects hormone levels, which can lead to anxiety.
Individuals with no genetic predisposition to anxiety can still develop an anxiety disorder from environmental factors alone. Unsupportive stressful environments over time can be overwhelming and trigger anxiety. Additionally, traumatic early life experiences or a neglectful, abusive home environment are risk factors for anxiety.
Medication Side Effects
Like depression, anxiety can be a side effect of medication use. Stimulants, corticosteroids, decongestants, medications containing caffeine, antihistamines, inhalers, antidepressants, and recreational drugs all have anxiety as a potential side effect.11
Withdrawal From an Illicit Substance
Withdrawal from illicit substances such as heroin, methamphetamine, and other drugs can cause anxiety. Symptoms of anxiety from withdrawal can be lasting, especially in post-acute withdrawal syndrome (PAWS), and can develop into an anxiety disorder.
Symptoms of a Medical Illness
Much like depression, anxiety can be related to a medical illness. Hypoglycemia, sleep apnea, Aspergers, asthma, cancer, celiac, COPD, high blood pressure, hormonal disorders, lupus, menstrual disorders, MS, and seizure disorders can all have anxiety symptoms.
Common Symptoms of Depression and Anxiety
Because depression and anxiety often are linked, they share many of the same symptoms. Symptoms like irrational worries, irritation, fatigue, headaches, changes in eating habits, difficulty concentrating, sadness and worthlessness, loss of interest, and feelings of hopelessness are common symptoms of depression and anxiety. Not every individual with depression and anxiety will experience all these symptoms. 12
However, individuals with severe anxiety and depression may experience these and more. Severe anxiety and depression symptoms include:
Irrational Worries or Fears
Fears and uncontrolled worry are hallmarks of both anxiety and depression. Individuals suffering from severe anxiety and depression may constantly worry or have irrational fears they cannot control.
Irritation or Frustration
For many individuals, depression and anxiety are expressed as irritation and frustration. Feeling irritable, restless, or angry can signify depression and anxiety. This is especially true for individuals with a history of trauma neglect, or abuse.
Fatigue, as well as changes in sleeping patterns, can also be indicative of anxiety and depression. Individuals with these conditions may either sleep too much, too little or just generally feel tired all of the time.
Headaches are also common for individuals with depression and anxiety. Tension headaches and migraine attacks are common for individuals with severe anxiety and depression.
Changes in Eating Habits
Individuals with depression and anxiety may also experience changes in eating habits. Individuals may experience a decrease in appetite or turn to binge eating to soothe stress. This leads to changes in weight often seen in individuals with depression and anxiety.
Difficulty in Concentrating
When we feel low or preoccupied with stress, it can be difficult to focus on anything else. Individuals with depression and anxiety may have difficulty concentrating. This can cause a decrease in productivity in the workplace or school, as well as make basic tasks difficult to accomplish.
General feelings of sadness are characteristic of both depression and anxiety disorders. Anxiety and depression can be exhausting and leave individuals completely depleted, leaving behind only sadness. While sadness is a normal part of life, persistent sadness can signify anxiety and depression.
Feelings of worthlessness are another symptom of anxiety and depression. Low self-esteem and self-worth are related to the development of these disorders and increase as other symptoms appear. Feelings of worthlessness make it difficult to find the motivation to seek help and suck individuals deeper into depression and anxiety.
Loss of Interest in Activities or Hobbies
Depression and anxiety typically also cause a loss of interest in activities or hobbies. Individuals may have difficulty finding enjoyment in past activities and hobbies. A sudden withdrawal from normal activities and hobbies is a major sign of anxiety and depression.
Individuals with depression and anxiety often experience hopelessness surrounding their lives and conditions. This lack of hope can make it immensely difficult to get help.
Treatment Options Available for Anxiety and Depression
Several treatment options are available depending on the severity of the condition. Common treatment options for anxiety and depression include therapy, medications, and natural remedies. While some individuals may only seek one treatment option, they can be immensely powerful in combination.
There are many therapy-based treatment options for depression and anxiety. Working with a therapist can help you better identify your triggers, work through your condition, and build a supported treatment plan. Interpersonal therapy, cognitive behavioral therapy, mindfulness-based cognitive therapy, and psychodynamic therapies are all effective options for treating depression and anxiety. 13
Many individuals find relief from depression and anxiety through medication. Because of the relationship between anxiety and depression, medications that are effective for depression are also effective for treating anxiety. There are six different classes of antidepressant and anti-anxiety drugs: selective serotonin reuptake inhibitors (SSRIs), selective serotonin & norepinephrine inhibitors (SNRIs), tetracyclic antidepressants, benzodiazepines, N-methyl-D-aspartate (NMDA) receptor antagonists, and monoamine oxidase inhibitors (MAOIs). Working with a psychiatrist can help you determine what medication will be most effective for you. 14
Both medication and therapy can be complemented by natural remedies. For individuals with less severe depression and anxiety, natural remedies can effectively manage symptoms. Natural therapies such as exercise, meditation, aromatherapy, and herbal teas can all be beneficial in treating anxiety and depression. 15
Get Professional Help For Depression and Anxiety at Alta Centers
Are you or someone you love suffering from anxiety and depression? Alta Centers can help. We believe every individual is unique, and our trained knowledgeable professionals will work with you to create a treatment plan tailored to your needs.