Causes of anxiety disorders

What causes anxiety?

Anxiety can be triggered by stressful experiences, uncertainty or perceived danger. Anxiety disorders are more complex and can develop through a combination of factors, including genetics, childhood experiences, prolonged stress, social circumstances, physical health conditions and the effects of medicines or substances. There is rarely one identifiable cause.

For some people, a particular event or change in circumstances may contribute to the onset of anxiety. For others, it may develop gradually through a combination of influences over time, without one obvious cause.

What is the difference between a cause, risk factor and trigger for anxiety?

The terms cause, risk factor and trigger describe different ways that biological, psychological and social influences can contribute to anxiety.

• Causes are the underlying processes or circumstances that contribute to the development of an anxiety disorder. These may involve several interacting factors rather than one identifiable cause. For example, someone may have an inherited vulnerability to anxiety, experience prolonged stress at work, and develop anxiety symptoms following a difficult life event.
• Risk factors are characteristics, experiences or circumstances associated with a greater likelihood of developing an anxiety disorder. Examples include a family history of anxiety, childhood adversity and prolonged exposure to stress.
• Triggers are events, situations or changes that bring on anxiety or contribute to its onset or a sudden increase in its intensity. These might include a loss or a period of significant uncertainty.

A systematic review of risk factors found associations with a range of sociodemographic, psychological and physical health factors. These findings highlight the importance of considering multiple influences: risk factors increase the likelihood of developing a disorder, while triggers may bring on or worsen symptoms.

How do genetics and biology contribute to anxiety disorders?

Biological factors can influence how someone experiences fear, responds to stress and processes potential threats. Genetics, brain development, the body’s stress-response systems and interactions with the environment may all contribute to the likelihood of developing an anxiety disorder.

Research into the genetics of generalised anxiety disorder and related traits suggests that inherited genetic differences can influence someone’s vulnerability to anxiety, but do not determine whether they will develop an anxiety disorder.

Biological processes involved in regulating emotions, learning from experiences and responding to perceived danger may also play a role. These processes involve networks of brain regions, chemical messengers and hormones rather than one isolated mechanism.
Genetic vulnerability can interact with experiences, relationships, stress and wider living conditions throughout life. The same biological predisposition may have different effects depending on the circumstances a person experiences.

Do anxiety disorders run in families?

Anxiety disorders can run in families. Studies into the development of anxiety disorders during childhood suggests that inherited genetic vulnerability, personality and temperament, family environments and learned behaviours can all contribute to anxiety.

Many genetic variations may influence vulnerability, each contributing a small amount. Having a family history of anxiety may increase someone’s risk, but it does not guarantee they will develop an anxiety disorder. Anxiety can also develop in people with no known family history.

Family environments can also influence how children respond to fear and uncertainty. For example, they may learn patterns of worrying or avoidance by observing adults around them.

How is the brain’s threat system involved in anxiety disorders?

The brain’s threat system helps us recognise danger and respond to potential threats. In people with anxiety disorders, these processes may contribute to heightened responses to perceived threats or difficulty distinguishing actual danger from uncertainty.

Several brain regions work together to process threats and regulate emotional responses. The amygdala plays a role in detecting potential threats, while fear learning helps us recognise situations associated with danger. These learned responses can sometimes persist even when a threat is no longer present.

Brain communication also involves chemical messengers called neurotransmitters, including serotonin, noradrenaline, dopamine and gamma-aminobutyric acid (GABA). These have different roles in processes such as mood, alertness, motivation and the regulation of neural activity. Differences in these systems may contribute to anxiety, although their roles are complex.

Research into the origins of anxiety disorders during childhood and adolescence explores how biological vulnerability, learning and environmental experiences interact in the development of anxiety.

Anxiety disorders cannot be explained by a single brain region, neurotransmitter or chemical imbalance. They involve complex interactions between brain processes, learning, individual experiences and environmental influences.

How can childhood experiences increase the risk of anxiety disorders?

Adverse childhood experiences can increase the risk of anxiety disorders by influencing how someone learns to respond to stress, uncertainty and perceived danger. These experiences may affect emotional development, relationships and feelings of safety.

A meta-analysis of prospective longitudinal studies examining childhood trauma and anxiety disorders explored the relationship between childhood adversity and the later development of anxiety disorders.

Experiences associated with increased risk include:

• Childhood trauma, including physical, emotional or sexual abuse.
• Neglect, or a lack of consistent care, safety and emotional support.
• Bullying and social exclusion, which can undermine confidence and feelings of belonging.
• Racism and discrimination, particularly when experienced repeatedly during childhood.
• Difficult separation experiences, which may affect a child’s sense of security.
• Family relationships and parenting experiences, including highly critical, harsh or overprotective environments.

These experiences do not affect everyone in the same way. Supportive relationships and a sense of safety can help protect against the effects of adversity. Many people who experience difficult childhoods do not develop anxiety disorders, and anxiety can develop without identifiable childhood trauma.

Which stressful life events and social factors can contribute to anxiety disorders?

Stressful experiences and social circumstances can influence the development of anxiety disorders, particularly when they affect someone’s sense of safety, stability, belonging or control over their life.

A systematic review of cohort studies examining risk factors for anxiety disorders considered a range of personal, psychological, economic and environmental factors associated with the subsequent onset of generalised anxiety disorder and panic disorder.

These influences can occur at any age. They may involve a single significant event, a period of major change or the cumulative effects of several difficulties. Examples include:

• Bereavement or the loss of someone important.
• Relationship breakdown, family conflict or separation.
• Bullying, harassment or discrimination.
• Difficulties at work, school, college or university.
• Financial insecurity, debt or unemployment.
• Housing instability or living in an unsafe environment.
• Loneliness, social isolation or limited access to supportive relationships.
• Exposure to violence, conflict or distressing events in the wider community.

The effect of these experiences depends on the person and their circumstances. A situation that contributes to anxiety for one person may not have the same effect on another.

Social and environmental influences can also overlap. For example, losing a job may create money problems, affect relationships and reduce social contact at the same time.

Can chronic stress or major life changes trigger an anxiety disorder?

Prolonged stress can contribute to the development of an anxiety disorder, particularly when someone experiences repeated pressure without enough opportunity to recover. Over time, persistent demands and uncertainty may make it harder to regulate emotional responses and cope with additional challenges.

Major life changes can also contribute to anxiety, even when they are not necessarily negative. Moving home, starting or leaving a job, beginning university, becoming a parent, retiring or experiencing changes in relationships can bring uncertainty and disruption to familiar routines.

Findings suggest that stressful life events may increase the risk of developing an anxiety disorder. For some people, a significant change or stressful event may coincide with the onset of an anxiety disorder. For others, anxiety may develop after a gradual accumulation of smaller pressures.

Stress does not automatically cause an anxiety disorder. Its effects depend on factors such as a person’s previous experiences, current circumstances and access to support.

Can bereavement, relationship breakdown, abuse or violence contribute to anxiety?

Experiences involving loss, fear or a threat to personal safety can contribute to anxiety.

Bereavement, divorce, the end of a significant relationship, domestic abuse, sexual violence, physical assault and other traumatic events may affect a person’s sense of security and their expectations of the world.

Studies examining childhood trauma and the later development of anxiety disorders supports an association between adverse experiences and subsequent anxiety. Research into risk factors for generalised anxiety disorder and panic disorder also considers stressful life events in adulthood.

Bereavement and relationship breakdown can bring uncertainty, loneliness and changes to everyday life. Abuse and violence may involve prolonged fear, intimidation or a continuing threat to safety. These experiences can contribute to anxiety during the event itself or afterwards.

The effects vary. Some people develop an anxiety disorder, while others experience distress that does not meet the criteria for a mental health condition. The circumstances surrounding an event and the support available afterwards may also influence its impact.

Anxiety disorders and trauma-related conditions such as post-traumatic stress disorder (PTSD) can share symptoms and occur together, but PTSD is a distinct diagnosis.

How can work, education and financial pressures increase the risk of anxiety disorders?

Work, education and financial circumstances can increase the risk of developing an anxiety disorder, particularly when they create prolonged stress or insecurity.

At work, contributing pressures may include excessive workloads, unrealistic expectations, bullying, workplace conflict, job insecurity and fear of redundancy.

In education, high workloads, examinations, pressure to achieve, fear of failure and concerns about future prospects can contribute to a build-up of stress. Transitions, such as starting university, may bring additional social and practical pressures.

Financial difficulties, including debt, rising living costs and struggling to afford essentials, can create persistent uncertainty. Unemployment or losing a regular income may also affect a person’s financial security, identity, routine and sense of belonging.

These pressures can overlap. For example, job insecurity may lead to financial difficulties, which can affect relationships and housing stability.

Experiencing these challenges does not mean someone will develop an anxiety disorder, but sustained pressure may increase the risk, particularly alongside other vulnerabilities.

Can housing problems and poverty contribute to anxiety disorders?

Poverty and housing insecurity can contribute to anxiety by creating ongoing uncertainty about basic needs, personal safety and the future.

Financial hardship may make it difficult to afford essentials such as food, heating, transport and housing. Inadequate housing, overcrowding, homelessness or the risk of eviction can undermine a person’s sense of stability and security. Living in an unsafe neighbourhood or being exposed to violence and crime can add further sources of stress.

Housing, income, employment and health are interconnected. Someone facing one difficulty may be more exposed to others, creating a cumulative effect on their circumstances and mental health. Deprivation can limit access to resources and opportunities such as social activities.

Can loneliness and social isolation increase the risk of anxiety?

Loneliness and social isolation can be associated with an increased risk of anxiety disorders, although the relationship works in both directions.

Loneliness describes the distress someone may feel when their relationships do not provide the connection they want. Social isolation refers to having limited social contact or connections. Someone can feel lonely while surrounded by others, or live alone without feeling lonely.

Limited social connection may leave someone with fewer opportunities to share concerns, feel understood or receive support. Life circumstances that can increase isolation include bereavement, unemployment, caring responsibilities, disability, long-term health conditions, discrimination and major life transitions.

Anxiety can also make social situations feel more difficult, leading someone to withdraw from relationships or activities. This can create a cycle in which anxiety and isolation reinforce each other.

Can discrimination, racism or marginalisation contribute to anxiety?

Discrimination, racism, harassment and social exclusion can increase the risk of anxiety disorders by exposing people to repeated stress, unfair treatment and threats to their sense of safety or belonging. Research has linked experiences of racism with poorer mental health, while research into the immediate effects of discrimination highlights its potential impact on mental health.

People who experience racism may feel anxious about prejudice or anticipate being treated unfairly. LGBTQIA+ people may face rejection, harassment or pressure to conceal aspects of their identity. Disabled people and other marginalised groups may encounter inaccessible environments, exclusion or repeated negative treatment.

These experiences can occur at work, in education, healthcare, public spaces, family relationships and online. Persistent discrimination or the anticipation of it can undermine trust and feelings of security, particularly when people have limited control over their circumstances or access to support.

Being part of a particular community does not itself cause anxiety. The relevant risk factors are experiences such as discrimination, hostile environments, social exclusion and unequal access to safety and resources.

Can physical health conditions, medicines or substances cause anxiety?

Some physical health conditions, medicines and substances can cause anxiety symptoms or make existing anxiety worse.

Physical conditions can affect the body in ways that resemble anxiety. For example, an overactive thyroid (hyperthyroidism) can cause symptoms such as a racing heart, restlessness and nervousness. The uncertainty and distress associated with an illness can also contribute to anxiety.

Some prescribed medicines can cause anxiety as a side effect, particularly when starting treatment or changing a dose. Stopping certain medicines can also cause withdrawal symptoms, including anxiety.

Substances such as caffeine can also trigger or worsen symptoms. Caffeine can provoke anxiety and panic symptoms, particularly in people who are more susceptible to them.

Anxiety symptoms caused by a physical health condition, medicine or substance can sometimes be difficult to distinguish from an anxiety disorder. The two can also occur together, so it is important not to assume that anxiety is always psychological or that a physical cause is necessarily responsible.

If anxiety develops or worsens after a change in health, medication or substance use, a healthcare professional can help identify possible causes and advise on appropriate next steps.

Can alcohol or recreational drugs cause or worsen anxiety?

Alcohol and recreational drugs can trigger or worsen anxiety, depending on the substance, the amount used and individual vulnerability.

Alcohol may temporarily reduce feelings of tension, but anxiety can increase as its effects wear off. Heavy or prolonged alcohol use can also contribute to anxiety, while withdrawal can cause significant anxiety and other symptoms.

Stimulant drugs can increase alertness and physical arousal, sometimes triggering anxiety or panic. Other substances can affect perception and mood, leading to intense anxiety, fear or a sense of danger.

Cannabis use and anxiety disorders are associated, but it is not always clear whether cannabis contributes to anxiety or whether other factors explain the relationship.

Anxiety can also lead someone to use alcohol or drugs to cope with distress. This can create a cycle in which substance use and anxiety reinforce one another, and anxiety and substance use disorders can occur together.

When anxiety is directly caused by intoxication, substance use or withdrawal, it may be diagnosed as a substance-induced anxiety disorder.

Why do the causes of anxiety disorders differ between people?

Anxiety disorders develop through different combinations of influences, so there is no single explanation that applies to everyone.

One person may have an inherited vulnerability and develop anxiety following a major life event. Another may experience prolonged financial or workplace stress alongside limited social support. Someone else may develop anxiety in connection with a physical health condition or the effects of a medicine or substance.

Research into the origins of anxiety disorders during childhood and adolescence examines how biological vulnerability, temperament, parenting and individual experiences can interact in different ways.

Even when two people share similar experiences, they may respond differently. Their developmental histories, temperament, biological characteristics, relationships and current circumstances may all influence how they experience and respond to stress.

The same factor can also have different effects at different stages of life. A change that feels manageable in one set of circumstances may become more difficult when combined with other pressures.

Understanding this variation is important because it avoids reducing anxiety to a person’s genes, personality, childhood or present circumstances alone. Anxiety disorders are complex, and their causes are often best understood as a combination of interacting influences.

Why are anxiety disorders more common among women?

Consistent findings highlight that anxiety disorders are more prevalent among women than men, with differences also observed during childhood and adolescence.

Researchers are investigating several possible explanations, including biological influences, hormonal changes, differences in social expectations and unequal exposure to stressful or traumatic experiences.

Studies suggest that females may be more exposed to certain forms of abuse and violence, which are associated with an increased risk of anxiety disorders.

Gendered expectations, discrimination, caring responsibilities, financial insecurity and pressure surrounding appearance or achievement may also contribute to stress in some circumstances.

These influences vary between individuals, and population-level differences do not predict how any one person will experience anxiety. Anxiety disorders can affect anyone, regardless of their sex or gender identity.

Can pregnancy, having a baby or menopause influence anxiety risk?

Pregnancy, the postnatal period and menopause can coincide with biological, physical, emotional and social changes that influence anxiety in some people, although these life stages do not inevitably lead to an anxiety disorder.

Pregnancy and the transition to parenthood can bring uncertainty, concerns about health and responsibility, disrupted sleep and changes in relationships. A systematic review estimated that 8.5% of postpartum women experienced one or more anxiety disorders.

Other studies have identified factors associated with new-onset or worsening anxiety during the perinatal period.

During the postnatal period, hormonal changes and the demands of caring for a baby may interact with existing vulnerabilities. Previous mental health difficulties, limited support and stressful circumstances can also influence anxiety risk.

Menopause brings hormonal changes alongside potential changes in sleep, physical health, relationships and caring responsibilities. However, evidence linking the menopausal transition to anxiety remains inconclusive.

These life stages are not standalone explanations for anxiety. Their influence varies according to individual vulnerabilities and wider circumstances.

Can you develop an anxiety disorder without an obvious cause?

An anxiety disorder can develop even when there is no clear event or circumstance that explains why it started.

The National Institute of Mental Health’s guidance on generalised anxiety disorder explains that generalised anxiety disorder (GAD) may arise through a combination of genetic, biological and environmental influences, and that its exact cause is not fully understood.

Anxiety can emerge gradually through a combination of biological vulnerability, temperament, past experiences and current circumstances, rather than following one identifiable event.

Not being able to identify a cause does not mean the anxiety is any less real or valid. Nor does it mean that someone has failed to understand themselves or their experiences. The development of anxiety disorders is complex, and a single, identifiable explanation is not always possible.

How do different anxiety risk factors combine over time?

Anxiety disorders can develop through the interaction of biological, psychological, developmental, environmental and social influences across a person’s life.

For example, someone with a family history of anxiety may experience childhood adversity, prolonged workplace pressure and a significant life change. These experiences may combine to increase their vulnerability, although none makes an anxiety disorder inevitable.

Another person may have no known family history or identifiable childhood adversity but develop anxiety in connection with a physical health condition, substance use or sustained social and financial pressures.

Studies into risk factors for the onset of panic disorder and generalised anxiety disorder and the relationship between childhood trauma and subsequent anxiety disorders highlights the importance of considering multiple influences rather than relying on one universal explanation.

The balance of influences can change over time, as earlier experiences shape responses to later stress and current circumstances introduce new pressures. This helps explain why anxiety disorders can emerge from different combinations of risk factors, shaped by each person’s circumstances and history.