Factors leading to ADHD

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the risk percentage for a child to develop ADHD if one parent has the disorder?

30%

75%

60% (correct)

45%

Which method of study revealed that ADHD is nearly three times higher in biological parents compared to adoptive parents?

Adoption studies (correct)

Family studies

Genetic studies

Longitudinal studies

What is the heritability estimate for ADHD regarding hyperactive–impulsive and inattentive behaviors?

85%

60%

75% (correct)

50%

In twin studies, what is the average concordance rate for identical twins regarding ADHD?

65% Signup and view all the answers

What central role does dopamine play related to ADHD?

Psychomotor activity and reward seeking Signup and view all the answers

Which receptor is primarily targeted by medications that reduce ADHD symptoms?

Dopamine transporter (DAT1) Signup and view all the answers

What interaction may explain mixed research findings on variants in DAT1 and ADHD?

Gene-environment interaction Signup and view all the answers

Which variant of the dopamine receptor gene is consistently associated with ADHD?

DRD4 (seven-repeat form) Signup and view all the answers

Which of the following factors is linked to a greater number of ADHD symptoms in genetically at-risk children?

Maternal smoking during pregnancy Signup and view all the answers

Which of the following studies provides evidence that ADHD runs in families?

Family studies Signup and view all the answers

What is one significant neurobiological factor associated with children with ADHD?

Smaller right prefrontal cortex Signup and view all the answers

Which brain structure is primarily implicated in ADHD according to brain-imaging studies?

Frontostriatal circuitry Signup and view all the answers

What does decreased arousal or arousability in children with ADHD suggest?

Reduced responsiveness to stimuli Signup and view all the answers

What pattern is observed in the brain maturation of children with ADHD?

Delayed maturation, especially in prefrontal regions Signup and view all the answers

Which abnormality is associated with ADHD during vigilance tests?

Under responsiveness to stimuli Signup and view all the answers

Which of the following areas of the brain has been suggested to have potential involvement in ADHD symptoms?

Cerebellum and thalamus Signup and view all the answers

What role do environmental factors play in the development of ADHD according to recent findings?

They need to be considered alongside genetic influences. Signup and view all the answers

What challenge is faced when interpreting neurobiological findings related to ADHD?

Complexity of symptoms in ADHD Signup and view all the answers

What is a limitation identified in current neuroimaging studies of ADHD?

They cannot isolate localized brain abnormalities reliably. Signup and view all the answers

What is suggested about the heritability of ADHD based on genetic studies?

Heritable components come from multiple gene interactions. Signup and view all the answers

Which gene has been linked to the personality trait of sensation seeking?

DRD4 dopamine receptor gene Signup and view all the answers

What is the significance of the default mode network in relation to ADHD?

It operates abnormally, not shutting off during task engagement. Signup and view all the answers

What percentage of ADHD heritability does recent research suggest is accounted for by common DNA variants?

20% to 30% Signup and view all the answers

How do ADHD symptoms differ between individuals whose symptoms persist into adulthood and those who do not?

Cortical thinning occurs only in persisting symptoms. Signup and view all the answers

Which maternal behavior is most consistently associated with an increased risk of ADHD in offspring?

Cigarette smoking during pregnancy Signup and view all the answers

Which gene system has been implicated, along with the dopamine system, in the risk for developing ADHD?

Serotonin system Signup and view all the answers

Which factor does not appear to correlate with ADHD symptoms based on early development considerations?

High levels of comfort during pregnancy Signup and view all the answers

What early developmental factors may compromise the nervous system and relate to ADHD symptoms?

Maternal nutritional status during pregnancy Signup and view all the answers

What does the ongoing research suggest about the interaction between genetics and environment in ADHD?

Genetic predisposition can be modified by environmental influences. Signup and view all the answers

What is a likely explanation for the association between maternal substance use and ADHD in children?

The relationship is influenced by both genetic and environmental factors. Signup and view all the answers

Which neurotransmitters are suggested to have selective deficiencies in children with ADHD?

Dopamine and norepinephrine Signup and view all the answers

What effect do stimulant medications have on children with ADHD and their parents?

Decrease ADHD symptoms and corresponding negative parent behaviors Signup and view all the answers

How do family influences impact ADHD symptoms according to the provided content?

They may exacerbate the severity of ADHD symptoms. Signup and view all the answers

What does the concept of 'goodness of fit' refer to in the context of ADHD?

The alignment of child temperament with parental interaction style Signup and view all the answers

What is indicated by the findings regarding mothers with higher levels of ADHD symptoms?

They show less positive parenting and more inconsistent discipline. Signup and view all the answers

What role does family conflict play in the context of ADHD symptoms?

It can heighten the severity of symptoms in children with genetic predispositions. Signup and view all the answers

What does the evidence suggest about the relationship between ADHD and family influences?

Family influences significantly determine ADHD outcomes but are not primary causes. Signup and view all the answers

What is a significant finding regarding children with ADHD in relation to family conflict?

They experience more interparental conflict, worsening their symptoms. Signup and view all the answers

How does the biochemistry of children with ADHD compare to those without ADHD?

No consistent differences in biochemistry have been found. Signup and view all the answers

What hypothesis is supported by the interaction between parenting practices and genetic risk for ADHD?

Parenting interactions can moderate the risk for developing ADHD. Signup and view all the answers

Study Notes

Genetic Influences

ADHD is highly heritable, with family, adoption, and twin studies showing a strong genetic component.
Biological relatives of children with ADHD have a 33% chance of also having the disorder.
Children with a parent with ADHD have an almost 60% chance of developing the disorder.
Adoption studies show rates of ADHD are nearly 3 times higher in biological parents than adoptive parents of children with ADHD.
Twin studies report heritability estimates for ADHD averaging 75%, making it one of the most heritable childhood disorders.
Identical twins have a 65% concordance rate for ADHD, twice that of fraternal twins.
Genes involved in dopamine regulation are linked to ADHD.
Dopamine plays a role in psychomotor activity and reward seeking.
Brain structures implicated in ADHD have high dopamine innervation.
ADHD medications primarily block the dopamine transporter, increasing dopamine availability in the synapse.
Studies show an association between ADHD and variants in the DRD4 dopamine receptor gene.
The DRD4 gene has been linked to sensation seeking and impacts brain regions associated with executive functions and attention.
Other genes involved in dopamine and norepinephrine regulation have been implicated in ADHD.
While specific gene variants are associated with ADHD, the heritable components are likely due to the interaction of multiple genes across chromosomes.
Associations have been found between ADHD and serotonin system genes.
It's unlikely that ADHD is caused by only one gene.

Pregnancy, Birth, and Early Development

Factors compromising nervous system development before and after birth may be linked to ADHD symptoms, including pregnancy and birth complications, maternal exposure to toxins and stress during pregnancy, low birth weight, malnutrition, early neurological trauma, and diseases of infancy.
These factors may elevate the risk of developing multiple problems besides ADHD.
Maternal cigarette, alcohol, or drug use during pregnancy can have damaging effects on the developing fetus.
Mothers of children with ADHD report higher rates of heavy smoking and psychosocial stress during pregnancy than mothers of control children.
A strong association exists between maternal cigarette smoking during pregnancy and ADHD, particularly for female offspring and children with a specific genetic risk for ADHD.
Exposure to alcohol before birth may lead to inattention, hyperactivity, impulsivity, and learning and behavioral impairments.
Mothers of children with ADHD have higher rates of substance use than control parents, both during and outside pregnancy.
Disentangling the influence of prenatal substance abuse from the cumulative impact of a negative family environment is difficult.
Cocaine use during pregnancy can adversely affect brain development and lead to higher rates of ADHD and other psychiatric disorders.
Pregnancy and birth complications, as well as prenatal substance use, may play a role in some cases of ADHD but are not the primary cause for most.

Neurobiological Factors

There is strong support for neurobiological causal factors in ADHD.
Children with ADHD exhibit differences in brain function, including reduced arousal, under-responsiveness to stimuli, deficits in response inhibition, and decreased blood flow to specific brain regions.
Brain-imaging studies suggest abnormalities primarily in the frontostriatal circuitry of the brain, involving the prefrontal cortex and basal ganglia, which are associated with attention, executive functions, delayed responding, and response organization.
Children with ADHD have a smaller right prefrontal cortex and structural abnormalities in areas of the basal ganglia than children without ADHD.
Brain differences may extend beyond the prefrontal cortex and basal ganglia, with potential involvement of total and right cerebral volumes, the cerebellum, and the thalamus.
The default mode network, typically active at rest and shutting off during task engagement, operates abnormally in ADHD.
New studies suggest that brain circuits may develop differently or later in ADHD.
Brain maturation may be delayed in children with ADHD, particularly in the prefrontal regions.
Differences in brain development have been observed between individuals with persistent and remitted ADHD, with persistent symptoms showing cortical thinning in the prefrontal cortex.
Brain-scan studies highlight the importance of the frontostriatal region and its connections to the limbic system, cerebellum, and thalamus in ADHD.
While neuroimaging studies identify structural and functional differences in the brain associated with ADHD, they do not explain the underlying causes.
Consistent findings across neuroimaging studies are challenging due to varying sample definitions and small sample sizes.

Neurophysiological and Neurochemical Findings

Neurophysiological and neurochemical abnormalities underlying ADHD are difficult to document.
Consistent differences in biochemistry of urine, plasma, blood, and cerebrospinal fluid between children with and without ADHD are absent.
The effectiveness of ADHD medications suggests the involvement of dopamine, norepinephrine, epinephrine, and serotonin, with most evidence supporting a deficiency in dopamine and norepinephrine.
Caution is required when drawing conclusions based on medication effects alone.

Family Influences

Psychosocial factors within the family account for a small amount of variation in ADHD symptoms.
Family influences are important in understanding ADHD as they may contribute to the severity of symptoms.
Interfering and insensitive early caregiving practices may exacerbate ADHD symptoms, especially in children with a specific genetic risk for ADHD.
Family conflict may increase the severity of hyperactive-impulsive symptoms in children at risk for ADHD.
Goodness of fit between a child's temperament and parent's interaction style plays a role.
Parents of children with ADHD often also have ADHD, which can disrupt early parent-child interactions.
Mothers with higher levels of ADHD symptoms may exhibit less involvement, less positive parenting, and more inconsistent discipline.
A parent-gene × child-gene interaction may be influential, with the effects mediated by the child-rearing environment.
Family problems may result from interacting with a child who is impulsive and difficult to manage.
Family conflict is likely associated with the emergence or persistence of oppositional and conduct disorder symptoms.
In children with a biological risk for ADHD, family conflict may worsen ADHD and related ODD and CD symptoms.
Many ADHD interventions aim to modify family interaction patterns to prevent escalating cycles of oppositional behavior and conflict.
Family influences play a significant role in the outcome of ADHD and its associated challenges, even if they are not the primary cause.

### Conclusion

ADHD has a strong biological basis and is inherited in many cases.
ADHD is likely a heterogeneous disorder with variations in neurobiology.
Research is uncovering specific brain areas and circuits involved in ADHD, but findings are correlational, and the specific causes are unknown.
A complex interplay exists between biological risk factors, brain development, environmental experiences, family relationships, and broader system influences shaping the development and outcomes of ADHD.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the genetic factors influencing Attention Deficit Hyperactivity Disorder (ADHD). It delves into studies involving family, adoption, and twins, highlighting the strong heritable nature of the disorder. Learn about the role of genes and dopamine in ADHD and understand the implications for treatment.