Genetics + Early life inputs

Can experiences early in life affect how an individual behaves as an adult?

Yes! Early life experiences, such as stress or nurturing (receiving care), can influence how genes are expressed and affect behaviour and well-being later in life.

How did researchers use mother rats and their pups to study the effects of early life experiences?

Researchers observed how much mother rats groomed (licked) and nurtured their baby rats, called pups, and examined how this affected their behaviour as adults.

• Highly nurtured pups: Received more grooming and care → tended to become calmer adult rats.

• Less nurtured pups: Received less grooming and care → tended to become more anxious adult rats.

Were the differences between calm and anxious adult rats caused by changes in their DNA?

No! The differences were associated with changes in gene expression, meaning how active certain genes were, rather than changes to the actual DNA sequence. This is an example of epigenetics.

What is the difference between genetics and epigenetics?

• Genetics: Involves the DNA and genes we inherit from our parents, which influence our characteristics.

• Epigenetics: Involves changes in how genes are expressed (turned on or off) without changing the DNA sequence itself. Environmental factors, such as stress or nurturing, can influence these changes.

Is anxious behaviour always a disadvantage?

No! Whether anxious behaviour is helpful or harmful depends on the environment. Anxiety can help an individual respond quickly to danger, but it may be disadvantageous in a safe environment.

How do calm and anxious rats behave differently in low-danger environments?

• Calm rats: Tend to do well because they experience less stress, can focus on finding food, and may achieve higher social standing.

• Anxious rats: Tend to do less well because they remain stressed even when danger is low, which can contribute to chronic health problems and lower social standing.

Why might anxious rats have an advantage over calm rats in high-danger environments?

Anxious rats are more alert and respond quickly to threats, helping them avoid predators and survive. Calm rats may be too relaxed and fail to recognize danger quickly enough.

What are the three characteristics of epigenetic patterns?

• Flexibility: Allow gene expression to change even though the DNA sequence remains the same.

• Environmental sensitivity: Gene expression can be influenced by changing environmental conditions, such as stress or nutrition. Some epigenetic information can also be passed to offspring.

• Reversibility: epigenetic changes can be reversed

What are early life stressors, and how can they affect an individual?

Early life stressors are negative or stressful experiences that occur during childhood. They can affect a person's physical, emotional, and psychological well-being, potentially influencing their health and behaviour later in life.

EXAMPLES INCLUDE)

• Family dysfunction: Conflict or instability within the family.

• Abuse or neglect: Experiencing harm or not receiving adequate care.

• Poverty: Growing up with limited financial resources.

• Loss or bereavement: Experiencing the death or loss of someone close.

• Chronic illness: Living with a long-term medical condition.

• Community violence: Being exposed to violence in one's surroundings.

• Humanitarian crises: Experiencing events such as war or displacement.

• Bullying: Repeatedly experiencing harmful behaviour from others.

• Parental mental health issues: Growing up with a parent experiencing mental health challenges.

• Parental incarceration: Having a parent who is imprisoned.

Why is early childhood development important for long-term health and well-being?

Early childhood is a period when the brain and important life skills are developing. Experiences during this time can influence:

1. Brain development: Emotional regulation, stress responses, and neurological development.

2. Mental health: Identity formation, resilience (ability to cope with challenges), and coping skills.

3. Relationships: Ability to form attachments and feel emotionally secure.

4. Education and learning: Academic performance and future educational outcomes.

5. Lifelong patterns: Behaviours and responses that may continue into adulthood.

Developmental Window

A period during development when certain experiences or environmental influences have an especially important effect on how the brain or body develops.

• THERE ARE 2 TYPES: CRITICAL AND SENSITIVE.

Critical Developmental Window

A specific period when certain experiences or biological processes are necessary for normal development. Missing these experiences can cause permanent developmental difficulties.

Sensitive Developmental Window

A period when an individual is especially responsive to certain experiences, making learning or development easier. Development can still occur later, but it may be more difficult.

• more flexibile than criticzl

What are the developmental windows throughout early life?

Developmental windows are periods when certain aspects of physical, emotional, and psychological development are especially important.

1. Prenatal period: Development before birth.

2. Infancy (0–2 years): Attachment and emotional development.

3. Early childhood (2–6 years): Emotional regulation, social skills, and coping strategies.

4. Middle childhood (6–12 years): Cognitive development, identity, and self-esteem.

5. Adolescence (12–18 years): Independence, identity, and mental health.

6. Puberty (approximately 10–14 years, varies): Physical sexual development and emotional well-being.

How can stress during the prenatal period (before birth) affect development?

Maternal stress or exposure to trauma during pregnancy can increase the risk of preterm birth, low birth weight, and developmental difficulties in the child.

hy is the infant stage (0–2 years) important for emotional development?

During infancy, babies begin forming attachments (emotional bonds) with their primary caregivers. These relationships help establish a foundation for emotional security and future relationships.

What important skills develop during early childhood (2–6 years)?

• Emotional regulation: Learning how to recognize and manage emotions.

• Social skills: Learning how to interact and communicate with others.

• Coping strategies: Learning ways to deal with stress, frustration, and challenges.

What important changes occur during middle childhood (6–12 years)?

• Cognitive development: Improvements in thinking, reasoning, learning, and problem-solving.

• Identity formation: Beginning to develop a stronger understanding of who they are.

• Self-esteem development: Building their sense of self-worth and confidence.

Why is adolescence (12–18 years) an important developmental period?

Adolescence is a period when individuals develop greater autonomy (independence) and a stronger sense of identity.

It is also a time of increased vulnerability to certain mental health challenges, including anxiety, depression, and substance use problems.

What changes occur during puberty, and how can they affect well-being?

Puberty involves the development of secondary sexual characteristics, such as body hair growth, breast development, and voice changes.

These physical changes can also influence self-esteem, body image, and emotional well-being.

What are the four main ways early life stressors can affect psychological and behavioural well-being?

1. Mental health issues: Increased risk of anxiety, depression, eating disorders, personality disorders, self-harm, and suicidal thoughts or behaviours.

2. High-risk behaviours: Increased likelihood of substance misuse, impulsive behaviour, risky sexual behaviours, and teen pregnancy.

3. Cognitive impairment: Difficulties with memory, learning, attention, and decision-making.

4. Attachment issues: Difficulty forming trusting, secure relationships with others.

What happens in the body when a person experiences stress?

1. Brain detects stress: The brain recognizes a threat and activates the body's stress response.

2. Stress hormones are released: The brain signals pathways involving the adrenal glands, leading to the release of hormones such as cortisol and adrenaline.

3. Body responds: These hormones prepare the body to handle the threat by changing heart rate, energy availability, and other bodily functions.

4. Long-term effects: If the stress response remains activated for too long, it can negatively affect the immune system and increase the risk of chronic health problems.

Adverse Childhood Experiences (ACEs)

ACEs are potentially traumatic or stressful experiences that occur during childhood, such as abuse, neglect, or family dysfunction. These experiences can increase the risk of physical and mental health problems later in life.

ACE study in class

Objective: To examine the relationship between negative childhood experiences and the risk of developing mental health problems and other negative health outcomes later in life.

Methods:

1. Researchers studied approximately 17,000 adults in San Diego, California.

2. Participants completed a questionnaire about 10 categories of adverse childhood experiences.

3. Researchers examined the relationship between the number of ACEs reported and negative health and social outcomes in adulthood.

Findings:

• High prevalence: ACEs were common, and many participants reported experiencing more than one during childhood.

• Negative long-term outcomes: ACEs were associated with an increased risk of mental health problems and other negative health and social outcomes.

• Dose-response relationship: The more ACEs a person experienced, the greater their risk of negative outcomes later in life.

What does a dose-response relationship mean in the context of the ACEs Study?

It means that as the number of adverse childhood experiences increases, the risk of negative health outcomes also increases.

• Example: Someone who experienced four ACEs would, on average, have a higher risk of certain health problems than someone who experienced only one ACE.

This does not mean everyone who experiences more ACEs will develop health problems.

Why was the ACEs Study important for understanding long-term health and well-being?

The study helped demonstrate that childhood trauma is common and is strongly associated with long-term physical, mental, and social health outcomes.

It increased awareness of how experiences during childhood can influence health throughout life.

• The findings encouraged policymakers and healthcare professionals to develop prevention programs, early interventions, and trauma-informed approaches to reduce childhood adversity and its long-term effects.

Trauma-Informed Care

An approach to healthcare and other services that recognizes how past trauma may affect a person's health and behaviour, and aims to provide safe, supportive care without causing additional distress.

What are the three main types of stress

1. Positive Stress

2. Tolerable stress

3. Toxic stress

Positive stress

Short-term, manageable stress that resolves quickly and can help with normal development.

Tolerable stress

More intense or longer-lasting stress that can be managed with supportive relationships and healthy coping strategies.

Toxic stress

Intense, frequent, or prolonged stress without adequate support, which can disrupt brain development and negatively affect long-term health.

What is toxic stress, and why is it especially harmful during childhood?

Toxic stress occurs when a child experiences intense, frequent, or prolonged adversity without adequate support from caregivers.

• It can keep the body's stress response activated for extended periods, potentially disrupting brain development, stress regulation, and long-term physical and mental health.

What kinds of experiences can contribute to toxic stress during childhood?

Both biological and psychosocial experiences can contribute.

1. Biological factors: Malnutrition, infectious diseases, injury or disability, premature or traumatic birth, and prenatal substance exposure.

2. Psychosocial factors: Witnessing violence, abuse or maltreatment, extreme poverty, parental conflict, and stigmatization.

Why do children respond differently to stressful or adverse experiences?

The effects of adversity depend on several factors:

1. Type of adversity: What stressful experience occurred.

2. Duration: How long the experience lasted.

3. Number of adversities: How many different stressors the child experienced.

4. Interactions between adversities: Whether multiple stressors make each other's effects worse.

5. Timing and developmental stage: The child's age and stage of development.

6. Temperament: How the child naturally responds to stress.

7. Pre-existing characteristics: Individual characteristics that may affect vulnerability or resilience.

8. Family environment: Whether supportive caregivers and relationships are available.

9. Health status: Existing health conditions that may influence how the child responds.

How can toxic stress during childhood lead to long-term health problems?

Toxic stress can affect the body through the following process:

1. Exposure to adversity: A child experiences intense or prolonged stress.

2. Biological changes: Stress-response systems become repeatedly or continuously activated.

3. Changes in development: Stress can influence gene expression (epigenetics), brain development, and how the body responds to future stress.

4. Childhood impacts: Increased risk of physical symptoms, learning difficulties, and behavioural problems.

5. Adult impacts: Increased risk of chronic physical and mental health conditions later in life.

What are some possible physical and behavioural effects of toxic stress during childhood?

• Physical effects: Headaches, asthma, increased infections, allergies, and poor dental health.

• Behavioural and developmental effects: Learning difficulties, attention problems, school absenteeism, and early substance use.

What are some potential long-term health consequences associated with toxic stress and childhood adversity?

Childhood adversity is associated with an increased risk of chronic conditions such as cardiovascular disease, chronic obstructive pulmonary disease (COPD), and some cancers.

It is also associated with mental health difficulties, substance use disorders, and increased risk of self-harm or suicidal behaviours.

How common are Adverse Childhood Experiences (ACEs)?

ACEs are extremely common. According to U.S. data presented in the lecture:

• 64% of adults experienced at least one ACE before age 18.

• 17.3% of adults experienced four or more ACEs.

Are all children equally likely to experience Adverse Childhood Experiences (ACEs)?

No. Children living in communities experiencing poverty, marginalization, violence, or social and economic inequalities may face a higher risk of ACEs.

This highlights the importance of health equity, which means ensuring everyone has a fair opportunity to achieve good health.

Why is preventing ACEs important for public health?

Preventing ACEs could reduce the risk of many long-term physical and mental health conditions.

The slide estimates that preventing ACEs could potentially avoid:

1. 1.9 million cases of heart disease.

2. 21 million cases of depression.

How can ACEs affect a person's life expectancy?

Experiencing a high number of ACEs is associated with a shorter life expectancy.

The lecture cites a study suggesting that individuals with high ACE scores may have a 20-year reduction in life expectancy compared with individuals with no ACEs.

This is a population-level association, not a prediction of how long an individual will live.

ow can experiencing multiple ACEs affect mental health later in life?

Experiencing four or more ACEs is associated with a greater risk of serious mental health and behavioural problems.

According to the lecture, individuals with four or more ACEs are:

1. 7.4 times more likely to experience alcoholism.

2. 12.2 times more likely to attempt suicide.

These statistics describe associations between ACE exposure and outcomes, not guaranteed consequences.

How can ACEs affect a child's education?

ACEs can interfere with emotional regulation, concentration, learning, and academic performance.

The lecture states that children experiencing two or more ACEs are nearly three times more likely to repeat a grade

What is the relationship between ACEs and involvement in the criminal justice system?

Childhood trauma is common among youth involved in the juvenile justice system. According to the slide, approximately one-third report exposure to multiple forms of trauma each year.

This does not mean childhood trauma automatically leads to criminal behaviour.

Why do ACEs create an economic burden on society?

ACEs can increase costs associated with healthcare, mental health treatment, education, and social services, while also reducing productivity.

The lecture estimates an annual economic burden of approximately $748 billion across Bermuda, Canada, and the United States.