5. Parents and Family as Risk Factors for ADHD

The influence of parents and family on children’s risk of ADHD can only be clearly classified as a physical or psychological cause in a few cases.
Examples: While physical illnesses in parents indicate a genetic risk for their children—and thus a physical cause—this is not clear-cut in the case of mental disorders in parents. In most cases, these disorders pose a genetic risk, but they also tend to increase psychological stress within the family. A low socioeconomic status can be a consequence of a parent’s ADHD (ADHD drastically impairs educational opportunities and career prospects) and can also have psychological effects on children. Even parental behavior (“parenting”), which is certainly a factor influencing mental health, is in turn influenced by the children’s ADHD symptoms.

Children whose parents were unmarried, unemployed, or without social security, or who faced a “very high” financial burden due to child care, or whose parents included at least one person with a disability certificate, had a 21% increased risk of ADHD, a 36% increased risk of a learning disability, and an 80% increased risk of ASD at age 5.5 years. This applied to 10.8% of the 19,185 children.¹

1. Incomplete Families¶

People with ADHD experience more frequent breakups in their relationships (even in adulthood) than persons without ADHD. In this regard, it remains unclear to what extent a higher rate of divorce or separation is a consequence of the parents’ ADHD—which is then genetically passed on to the children—and to what extent single-parent or broken families contribute to ADHD.

1.1. Divorce (+193% to +384%)¶

Divorce: 193% to 384% increased risk of ADHD in children (meta-analysis, k = 11, N = 11,929)² This finding does not align with our experience. The figure seems inflated to us.

1.2. Single parents (up to +163%)¶

Single parent:

• a 61% increased risk of ADHD (meta-analysis, k = 5, N = 1,174,547)²
• a 163% increased risk of ADHD (2.63 times higher; a 25-year cohort study, N = 16,365).³

Single-parent families increase the risk of ADHD in children.⁴⁵⁶⁷
Single parents naturally face a higher risk of being unable to provide their children with sufficient love, care, and security. However, there are certainly single parents who are very capable of doing so. What matters is not the amount of time that (part-time or full-time working) parents can (or cannot) spend with their children, but whether the children have a consistent and secure sense that they are accepted and loved just as they are, at all times.

2. Low socioeconomic status of the family of origin (+63% to +310%)¶

When calculating the percentages, the two lowest and the two highest values out of the 9 were excluded.

Children from “lower-class” families are more likely to have ADHD^{85 9} and are more likely to be prescribed ADHD medication.¹⁰⁶
Children from the lowest socioeconomic class have roughly twice the risk of ADHD (+100%) as children from the highest socioeconomic class (in a three-class model).¹¹

Likewise, cramped living conditions increase children’s risk of ADHD.⁵
A family’s poor financial situation correlated with

• a 2.12-fold increased risk (+112%) of ADHD symptoms in preschool-aged children in the United States.¹²
• a 39% increased risk of ADHD and a 27% increased risk of ASD (a 25-year cohort study, N = 16,365).³

The overall prevalence of ADHD among children and adolescents was found to be 2.2% in the 2007 Bella Study¹³ (a figure we consider to be too low). A sub-study of the Bella study with N = 2,500 participants between the ages of 7 and 17¹⁴ reports a prevalence of approximately 5% based on parental assessments. Both findings confirm a significant disparity in prevalence across social classes. According to the 2007 Bella study, the middle class has a prevalence of approximately 2.3%, while the lower socioeconomic class has a prevalence of 3.7%—more than four times as high (+310%) as that of the upper class (0.9%).¹⁵ The Bella sub-study reports a prevalence of ADHD in the lower social class (7.2%) that is approximately 2.57 times higher (+157%) than in the upper class (2.8%) (based on 3 social classes).¹⁴
In a Danish cohort study, the risk of ADHD among children increased:¹⁶

• by 2.1 percentage points (+57%) among children with low-income parents
• by 2.3 percentage points (+63%) in parental unemployment
• by 3.5 percentage points (+95%) among parents with a low level of education
• by 4.9 percentage points (+133%) when all three criteria were met.

We view the fact that this pattern is not limited to ADHD but is found in exactly the same way in other mental disorders—such as anxiety, depression, or social behavior disorders—as strong evidence supporting the hypothesis that stress is a causative factor in the development of mental disorders. Like ADHD, these other mental disorders are also based on a multigenetic predisposition that is epigenetically manifested by stress exposure in early childhood.¹⁷¹⁸¹⁹

⇒ Gene Candidates and Early Childhood Stress as Causes of Other Mental Disorders

2.1. Low socioeconomic status as a risk factor for ADHD¶

A genetically predicted socioeconomic status that was one standard deviation lower causally predicted a 5.3-fold increased risk of ADHD (+430%), whereas, conversely, ADHD had only a very small causal effect on socioeconomic status. A genetically predicted family income that was one standard deviation higher causally predicted a 65% lower risk of ADHD. Here, too, the reverse effect was small.²⁰

Among children in the United States, poverty was associated with reduced white and gray matter volume, as well as reduced hippocampal and amygdala volume.²¹ Reduced white and gray matter volume is a neurophysiological correlate of ADHD.
Poverty in the U.S. is still associated with greater material resources than the standard of living in many other countries. Purchasing power at the poverty line in the U.S. is around $9,000. This is higher than the average purchasing power in Mexico or South Africa ($6,000). Therefore, the objective amount of resources (purchasing power) cannot be the decisive criterion.
In the U.S. in particular, the social gap between the median income (which is significantly higher than in other countries) and poverty is much more drastic than in other countries because, compared to other similarly developed countries, there is much less government social safety net coverage to ensure a minimum standard of living, and health care costs are borne privately to a greater extent. The U.S. has one of the highest prevalences of ADHD worldwide. In our view, this suggests that the relative gap between poverty and average income, in particular, contributes to ADHD. This suggests that, in addition to the characteristics of people who are more likely to slip into poverty (ADHD as a cause of poverty), poverty itself can be a psychological stressor (feeling less included) that contributes to ADHD.

Income appears to be most strongly associated with brain structure, particularly among the most disadvantaged children. Among children from low-income families, small differences in income correlated with relatively large differences in cortical surface area, whereas among children from higher-income families, similar differences in income were associated with smaller differences in surface area. These associations were most pronounced in regions that support language, reading, executive functions, and spatial abilities; cortical surface area thus mediated socioeconomic differences in specific neurocognitive abilities.²²

Among college students, too, lower financial resources appear to correlate with increased ADHD symptoms.²³ However, there was no association with (self-inflicted) student debt.

Low socioeconomic status can therefore be viewed as a chronic stressor.²⁴
Epigenetic studies suggest that the consequences of chronic stress may be passed on to offspring.²⁵ In male rodents, chronic stress altered DNA methylation and microRNA profiles, thereby influencing the epigenetic content of their sperm in a way that affected their offspring’s stress responsiveness and brain development.²⁶
In humans, men exposed to trauma or adverse circumstances were found to have epigenetic marks that they passed on to their offspring, thereby increasing the risk of neurodevelopmental problems.²⁷
Epigenetic changes caused by psychological stress can influence the expression of genes associated with ADHD and autism. These epigenetic effects are environmentally induced and potentially reversible.²⁸

2.2. ADHD as a Risk Factor for Low Socioeconomic Status (?)¶

ADHD is primarily caused by genetic factors. ADHD is associated with reduced educational opportunities, more frequent job losses, and lower income. This suggests that ADHD is a risk factor for low socioeconomic status.

Parents of children with ADHD showed higher levels of cognitive deficits (IQ, reading tasks, verbal language skills), the highest stress levels of all the parent groups compared, the most ADHD symptoms, and poor reading performance.²⁹

In addition, there is evidence that (with regard to children with ADHD) environment-centered psychotherapies (interventions within the family, with parents, at preschool, or at school) are more effective than patient-centered behavioral therapies. In some cases, the effectiveness of patient-centered behavioral therapies has been questioned.³⁰ This is likely to be particularly true for younger children (up to 6 or 8 years old).
This could suggest that external factors are a significant cause of ADHD in children.

Families with high socioeconomic status did not benefit from behavioral therapy administered in addition to medication. Only families with low socioeconomic status benefited more from a combination of medication and behavioral therapy than from medication alone.³¹

On the one hand, we suspect that socioeconomic status (income or the size of the home itself) is not the decisive factor, but rather that these circumstances more often correlate with the parents’ own problems, which in turn are associated with inappropriate parenting methods.
Pure behavioral therapy places a clear emphasis on reducing symptoms. It is conceivable that the ability to adapt behavior to given circumstances could, on the one hand, lead to greater professional success and thus to a higher socioeconomic status, and, on the other hand, better manage ADHD symptoms in oneself and in children. Such a greater capacity for behavioral adaptation would, in and of itself, have a behavior-correcting effect and would anticipate the behavioral adjustments achieved through behavioral therapy.

2.3. A Comparative Analysis of the Influence of Socioeconomic Status and Education on Mental Health Problems¶

Although socioeconomic status has a significant influence on many disorders, this influence varies in degree.

3. Parental diabetes (up to +286%)¶

3.1. Father’s diabetes (+286%)¶

Among children under 5 years of age, the risk of ADHD was 286% higher if the father had diabetes.⁷¹ The question asked was, “Does the newborn’s father currently have diabetes mellitus diagnosed by a doctor?” so the specific type of diabetes was not determined.⁷²

3.2. Gestational diabetes in the mother (+53%)¶

Gestational diabetes in the mother increased the child’s risk of ADHD by 53%.⁷³

In studies that accounted for multiple confounding factors, maternal diabetes before or during pregnancy was associated with an increased risk (meta-analysis, k = 98)⁷⁴

• by 28% for any type of neurodevelopmental disorder
• by 25% for ASA
• by 30% for ADHD
• by 32% for intellectual disabilities
• by 27% for specific developmental disorders
• by 20% due to communication breakdowns
• by 17% for motor disorders
• by 16% for learning disabilities

3.3. Maternal diabetes before pregnancy¶

Children of mothers who had diabetes before pregnancy had a 39% higher risk of a neurodevelopmental disorder than children of mothers with gestational diabetes. (Meta-analysis, k = 202, N = 56,082,462 mother-child pairs)⁷⁴

4. Maternal heart disease (+189%)¶

Among children under 5 whose mothers had a heart condition at birth, the risk of ADHD was 189% higher.⁷¹

5. Parents’ Mental Health Issues (up to +125%)¶

Mental health issues in parents increase the risk of ADHD in their children.⁷⁵⁶
Parents’ mental health issues could act as environmental and/or genetic factors.

5.1. Depression (+42% to 125%)¶

Depressive symptoms in a father or mother increase the risk of ADHD in their children⁹

• by 110% to 116%⁷⁶
• by 66%⁷⁷
• by 42% to 125%:⁷⁸
  • before pregnancy
    • Depression in a parent:
      • ADHD + 92%
      • ASS + 63%
    • Maternal depression:
      • ADHD + 125%
      • ASS + 101%
  • during childbirth
    • Depression in a parent:
      • ADHD + 72%
      • ASS + 88%
    • Maternal depression:
      • ADHD + 75%
      • ASS + 58%
  • during the child’s first year of life
    • Depression in a parent:
      • ADHD + 71%
      • ASS + 110%
    • Maternal depression:
      • ADHD + 55%
      • ASS + 59%
  • when the child is between 2 and 4 years old
    • Depression in a parent:
      • ADHD + 52%
      • ASS + 101%
    • Maternal depression:
      • ADHD + 55%
      • ASS + 64%
  • starting at age 4
    • Depression in a parent:
      • ADHD + 42%
      • ASS + 85%
    • Maternal depression:
      • ADHD + 43%
      • ASS + 65%
• Maternal depression increases the risk of ADHD and ASD in children more than paternal depression does⁷⁹

5.2. Bipolar Disorder (+100%)¶

Bipolar disorder in one parent doubled the children’s risk of ADHD.⁸⁰ Another study also found an increased risk of ADHD.⁸¹

5.3. The Father’s Antisocial Personality Disorder¶

An antisocial disorder in a parent poses a significant (and usually violent) risk of ADHD in their children.⁵

5.4. Schizophrenia¶

Schizophrenia in one parent increased the children’s risk of ADHD.⁸²

5.5. Father’s Alcohol Problems¶

Alcohol problems in the father increase the risk of ADHD in his children.⁴

5.6. ADHD in Parents¶

When parents have ADHD, it not only increases the child’s risk of inheriting ADHD genetically, but also—regardless of genetics—poses an increased risk of the child adopting dysfunctional lifestyle habits. At the same time, it can be beneficial for a child with ADHD if parents have learned to manage their own ADHD effectively and can therefore more consciously teach functional compensatory coping strategies. However, there is a significant proportion of parents who are themselves people with ADHD and who refuse to acknowledge this in themselves. This often leads to additional conflicts due to a more or less conscious rejection of the affected child’s behaviors, for which the child is not to blame.
Furthermore, even the most dedicated parents—like anyone else—may not always live up to their own ideals.

A study examined the influence of ADHD in mothers on ADHD in their children, specifically to determine whether similarities between parents and children improve or worsen parenting. Children’s ADHD symptoms correlated with negative comments from their mothers, and mothers’ ADHD symptoms correlated with the negative emotions they expressed. Nevertheless, maternal ADHD symptoms appeared to mitigate the effects of children’s ADHD symptoms on negative parenting. Parents’ responses to children with severe ADHD symptoms were more positive and affectionate when the mother also exhibited severe ADHD symptoms.⁸³
Another study from 2006 found that 95% of Polish parents physically punished their children, which constitutes abuse. Parents with ADHD used more severe forms of physical punishment. A parenting training program resulted in 72% of parents using other types of punishment.⁸⁴ Among Iranian parents as well, those with ADHD were more likely to use physical punishment and showed less parental warmth.⁸⁵

ADHD Symptoms⁸⁶

• in the father, correlated with
  • more social-emotional difficulties among boys (+68%)
  • fewer socio-emotional difficulties among girls
• in the mother correlated with
  • an increase in socio-emotional problems among girls (+109%)
• in both parents correlated with
  • an increase in children’s social-emotional difficulties (+343%).

Mothers with ADHD had more difficulty monitoring their children’s dental care and oral health.⁸⁷
On the other hand, children with ADHD symptoms in Spain had a higher risk of:⁸⁸

• Tooth decay (OR: 2.16)
  • A rather troubling study linked MPH (particularly the immediate release form) to tooth decay without including people with ADHD who were not taking MPH as a control group⁸⁹
• Extraction (OR: 1.42)
• Restoration (OR: 1.47)
• Bleeding gums (OR: 1.64)
  The increased risk of tooth decay persisted even when the analysis was limited to families in the middle/upper socioeconomic class and children with low sugar intake, good oral hygiene habits, and regular dental visits.

6. Parent’s incarceration (+10% to +114%)¶

Parental incarceration: 10% increased risk of ADHD (meta-analysis, k = 3, N = 4,073)² A registry study found a 114% increase in the risk of ADHD between the ages of 3 and 5 (HR = 2.14) (registry study, N = 631,695).⁹⁰

7. Unplanned pregnancy (+105%)¶

A prospective cohort study (N = 7,910) spanning 16 years found that an unintended pregnancy was associated with symptoms of hyperactivity in children at age 8 (+108%), but not with ADHD symptoms at age 16 (+13%, not significant).⁹¹

8. Low parental educational attainment (+3.5% to +95%)¶

The criterion in each case is the highest level of education attained.

8.1. Educational Attainment and ADHD Risk¶

A low level of education on the part of the mother⁹² or the parents⁹³, as well as on the part of the father, increases the risk of ADHD in children (a 25-year cohort study, N = 16,365³).
Children whose parents did not have a college degree were twice as likely to have ADHD as children whose parents did have a college degree.⁹⁴
A lower level of education among mothers is said to correlate with increased screen time among children, which in turn correlates with behavioral problems.⁹⁵
In a cohort study conducted in Denmark, a low level of parental education was associated with a 3.5% increased risk of ADHD in children.¹⁶ Children whose parents were unemployed and had low incomes and low levels of education were found to have a 4.9% increased risk of ADHD.
An Ethiopian study found that children’s risk of ADHD was roughly three times higher if their mothers were illiterate.⁹⁶

• 72% for children aged 5 whose mothers had a college degree (university or technical college), according to a cohort study in Taiwan ⁷¹ (not statistically significant)
• a 50% reduction among 5-year-old children whose mothers had a senior high school diploma (12th grade), according to a cohort study in Taiwan ⁷¹ (not statistically significant)
• by 94% among 5-year-old children whose mothers had a junior high school diploma (9th grade), according to a cohort study in Taiwan ⁷¹ (not statistically significant)
• by 29% among 5-year-olds whose mothers had completed elementary school (6th grade), according to a cohort study in Taiwan ⁷¹ (not statistically significant)

In a Danish cohort study, the risk of ADHD among children increased:¹⁶

• by 3.5 percentage points (+95%) among parents with a low level of education

A genetically predicted educational attainment level that was one standard deviation higher was causally associated with a 70% lower risk of ADHD.²⁰

8.2. Educational Attainment, ADHD Severity, and Treatment¶

Children of parents with low educational attainment had more severe ADHD symptoms and nearly double the risk of severe ADHD symptoms. This association was independent of genetic and family environmental factors. The association between this model and depression was weaker and could be fully explained by shared genetic factors.⁹⁷
Children of parents with lower levels of education were significantly less likely to receive appropriate treatment for their ADHD.⁹⁸

9. Injuries to a parent (+69%)¶

In a registry study, children and adolescents (ages 5 to 17) whose parents required medical treatment due to an unintentional injury showed:⁹⁹

• a 69% increased risk of ADHD
• a higher Washington Group Composite Disability Score (OR 1.77)
• a 129% higher risk of injury to oneself
• a 49% higher risk of requiring emergency medical care themselves

It remains unclear whether the increased risks are a psychotraumatic consequence of the parent’s injury or a consequence of the fact that the genetic heritability of ADHD is 80 percent and the parent’s injury was a result of their own ADHD, since ADHD is known to carry a higher risk of injury or of seeking emergency care.

10. Parents’ age (+14% to +66%)¶

10.1. Young age of parents (+14% to +66%)¶

A Danish cohort study (n = 943,785) found that the risk of ADHD was more than double when parents were 20 years old or younger, compared to parents aged 26 to 30.¹⁰⁰ Children whose mothers do not have ADHD have a 14% increased risk of ADHD if one parent is younger than 20 years old. Children whose mothers have ADHD have a 92% increased risk of ADHD if one parent is younger than 20 years old.¹⁰¹¹⁰² Another study also reports that younger fathers were more likely to have children with ADHD than older fathers.¹⁰³ One study reports a 32% reduced risk of ADHD for every 10-year increase in maternal age. However, the correlation was weakened by other factors. These were:¹⁰⁴

• Family income
• Training for Caregivers
• polygenic ADHD risk score
• Duration of breastfeeding
• prenatal alcohol exposure
• prenatal exposure to tobacco

In cohort studies, children with ADHD also had mothers who were younger than average:
Under 24 years of age: 1.66 times (+66%)¹⁰⁵
Over 24 years: 0.93-fold (7% decrease) (cohort study spanning 25 years, N = 16,365)³
Ages 25 to 29: 0.92 times (down 8%)¹⁰⁵
Ages 30 to 34: 0.66 times (down 34%)¹⁰⁵
Over 35 years: 0.58 times (down 42%)¹⁰⁵

Father older than 24 at the time of birth: 0.95-fold risk (5% lower) (cohort study spanning 25 years, N = 16,365)³

Another study reports the same findings, noting an increase in learning difficulties among particularly young mothers (ages 20 to 24) and particularly older mothers (ages 35 to 39).¹⁰⁶

In a large-scale study, just under 2 out of 3 young mothers reported at least one mental health problem. Nearly 40% had more than one. Young mothers were two to four times higher than among older mothers in the comparison group or women aged 15–17, and they were two to four times more likely to have more than one mental health problem.¹⁰⁷

A study found no link between the mother’s age and her child’s risk of ADHD.¹⁰⁸

Children with ADHD whose mothers were 25 years old or younger at the time of their birth had¹⁰⁹

• a 23% increased risk of anxiety disorders (OR = 1.23)
• a 41% increased risk of adjustment disorders (OR = 1.41)

Children with ADHD whose fathers were 20 years old or younger at the time of their birth had¹⁰⁹

• a 258% increased risk of bipolar disorder (OR = 3.58)
• a 39% increased risk of anxiety disorders (OR = 1.39)

10.2. Older parents (+55%)¶

A Taiwanese cohort study found a 55% increased risk of ADHD among 5-year-old children born to older mothers⁷¹ who were 35 years of age or older⁷².

Children with ADHD whose mothers were 35 years of age or older at the time of birth had¹⁰⁹

• a 47% increased risk of ASA (OR = 1.47)
• a 33% increased risk of speech development delay (OR = 1.33)

11. Parents’ Employment Status¶

11.1. Parental Unemployment (up to +63%)¶

Parental unemployment was associated with an increased risk of ADHD in children

• by 48% at age 5 among children whose mothers were unemployed, according to a cohort study in Taiwan, compared with children whose mothers worked during the day (not at night, on shift work, or on rotating shifts)⁷¹
• by 4.9% among children of unemployed parents with low income and low educational attainment. Parental unemployment or employment-related problems increased ADHD symptoms in children.⁷
• by 2.3 percentage points (+63%) in a cohort study in Denmark¹⁶

11.2. The Mother’s Employment Status¶

Among children under 5 whose mothers worked, the risk of ADHD was elevated

• by 84% when switching between night and day shifts⁷¹ (not statistically significant)
• a 73% increase in mothers’ nighttime work hours⁷¹ (not statistically significant)
• by 12% for work performed during the day and at night⁷¹ (not statistically significant)

12. Maternal thyroid problems (+23%)¶

However, maternal hyperthyroidism—which was first diagnosed and treated after the child’s birth—increased the child’s risk of ADHD by 23% and the risk of ASD by 34%.¹¹⁰

13. Parenting / Parental Behavior¶

The influence of family factors on the development and persistence of mental disorders in children and adolescents has been extensively studied.¹¹¹

13.1. Parental Attachment Patterns During the (Early) Childhood Years¶

13.1.1. Lack of attachment on the part of the mother/parents during the (early) childhood years¶

A lack of a secure attachment between a child and its mother, like social and emotional deprivation, has far-reaching negative effects on the child’s mental health, even in later years.¹¹² Insecure attachment contributes to ADHD (meta-analysis, k = 29)¹¹³

The strength of the infant’s bond with the mother or primary caregiver determines the level of the stress hormone cortisol in the baby’s brain.

Disorganized attachment behavior is a risk factor for ADHD.¹¹⁴ Attachment disorders in children during the first years of life, when combined with a corresponding genetic predisposition, lead to activation of the DRD4 gene, which is also frequently involved in ADHD.¹¹⁵ A lack of persistence on the part of parents has been cited as a risk factor for ADHD,¹¹⁶ although impatience is itself a symptom of ADHD and may therefore also be an indication of ADHD in the parents and thus of genetic transmission.

Severe stress experienced by the mother during the early years of a child’s life causes significant epigenetic changes in the child’s DNA.¹¹⁷

In borderline personality disorder—which typically arises from intensely stressful attachment disturbances with caregivers during early childhood (the first 2 years) due to physical, sexual, or psychological abuse—there is a significant rate of comorbidity with ADHD.¹¹⁸

13.1.2. Emotionally distant fathering during infancy¶

A study examined father-infant interactions and their impact on emotion regulation in toddlers and ADHD symptoms in middle childhood.
Emotional withdrawal on the part of fathers during infancy and a tendency to downplay their children’s fears during early childhood predicted the development of ADHD symptoms in middle childhood. Fathers’ parenting behavior when their children were 8 and 24 months old significantly influenced the risk of ADHD at age 7 through the toddlers’ difficulties with emotion regulation.¹¹⁹

13.1.3. Rejecting Parental Behavior¶

Latent parental rejection or coldness mediated the relationship between the parents’ anxious attachment and the child’s behavioral problems, as well as between the parents’ attentiveness and the child’s problems. Parental rejection was the strongest predictor of the child’s difficulties.¹²⁰

13.1.4. Negative Emotions and Behaviors of Parents¶

Negative emotions and behaviors exhibited by parents toward children aged 18 months were associated with an increased risk of ADHD up to age 17 and ADHD symptoms that were approximately twice as severe compared to when parents displayed positive emotional engagement and verbal communication. ASD, on the other hand, was associated with dysregulation and irritability in children, even during infancy.¹²¹

13.2. Parental Parenting Styles¶

Parental upbringing is likely to be only a minor contributing factor in the development of ADHD in children. Its influence on how well children are able to cope with existing ADHD is likely to be greater.

Nevertheless, numerous studies confirm that parenting styles influence ADHD in children.^{122123124125126127128129130131132133134135}

In one study, SHR rats—a model for ADHD—were raised by non-ADHD rat mothers, and non-SHR rat pups were raised by SHR mothers. The results showed that:¹³⁶

• motor hyperactivity depended entirely on ancestry
• Social behavior was primarily shaped by the mother who raised the child
• Attention-orientation behavior was influenced by both the offspring’s ancestry and the mother’s ancestry
• anxiety-related behavior was influenced by an interaction between the offspring’s ancestry and the mother

This is consistent with the finding that critical maternal behavior was a strong risk factor (+73%) for high levels of externalizing ASD symptoms, while maternal warmth was a significant protective factor.¹³⁷

An enriched environment—one that offers plenty of stimulation and manageable challenges—reduced ADHD symptoms in SHR mice.¹³⁸

When it comes to parental upbringing, a distinction must be made between¹¹¹

• Attitudes (parents’ internalized cognitions and beliefs about child-rearing, including parental goals and parental knowledge)
• Behavior (the way one acts in certain situations)
  even though behavior is strongly influenced by one’s attitude.

Children with ADHD in the United States received significantly less maternal attention than children without ADHD at six observed time points between the ages of 3 and 15. Mothers with higher levels of education were less likely to provide little attention than mothers with lower levels of education.¹³⁹ Children with ADHD were more likely at every age to experience very little support from their mothers and, across two or more age groups, to experience very little support from their mothers. Boys with ADHD were more likely than girls with ADHD to experience very little support from their mothers.

13.2.1. Authoritative Parenting Style¶

Authoritative parenting involves clear expectations, consistent rules, and a supportive, encouraging environment.
Discipline: Focuses on teaching, with explanations of rules and consequences.
Communication: open and two-way. Parents actively engage with their children’s perspectives.
Results: promotes high self-esteem, academic success, and social skills in children.
An authoritative parenting style was correlated with

• less frequent cyberbullying¹⁴⁰
• less problematic internet use¹⁴⁰
• fostered a more positive parent-child relationship¹⁴⁰
  • which, in turn, helped reduce cyberbullying and problematic internet use
• less common ADHD¹⁴¹

13.2.2. Authoritarian Parenting Style¶

Authoritarian parenting emphasizes high standards, strict rules, and obedience.
Little warmth or responsiveness on the part of the parents.
Discipline: punishment-oriented, with little explanation or consideration for the child’s perspective.
Communication: one-sided, with limited dialogue or opportunities for children to express their opinions.
Results: Impairs self-esteem¹⁴², contributes to anxiety and problems with emotional regulation in children
An authoritarian parenting style

• was associated with a higher prevalence of ADHD^{141143144140145}
• increased learning difficulties¹⁴⁰

Low levels of maternal warmth and increased maternal negativity were correlated among children aged 12 and 18¹⁴⁶

• with externalizing symptoms
• with more severe general psychopathology
• but not with internalizing symptoms

Children from a school with a punitive disciplinary style lied much more frequently and developed the skills needed to lie several years earlier.¹⁴⁷

13.2.3. Permissive Parenting Style¶

Permissive parenting involves few demands, few rules, and little structure, combined with a high degree of warmth and responsiveness.
Discipline: lenient, with a tendency to avoid confrontations or setting boundaries.
Communication: very open and accepting; children are often treated as equals.
Results: May promote impulsivity, difficulties with self-control, and risky behavior.
A permissive parenting style was correlated with

• ADHD is more common than with an authoritative parenting style, but less common than with an authoritarian parenting style¹⁴¹
• a lower incidence of ADHD than with authoritarian and overreactive parenting styles¹⁴³

13.2.4. Overreactive Parenting Style¶

• ADHD Is More Common Than a Permissive Parenting Style¹⁴³

13.2.5. Overprotective Parenting Style¶

• ADHD is more common¹⁴⁸¹⁴⁵
• frequent anxiety¹⁴⁸

Parental warmth and consistency have a positive effect on the social-emotional behavior of children with ADHD.¹⁴⁹

Furthermore, a distinction must be made between:¹⁵⁰

• positive parenting behaviors¹¹¹
  • Emotional responsiveness, parental warmth (the extent to which parents behave in a supportive, accepting, nurturing, and warm manner toward their child)¹⁵¹
    • SMD minus 0.16 (reduced risk of ADHD; meta-analysis, k = 10, N = 2,475)²
  • Behavior management (parenting practices such as guidance, direction, setting boundaries, and supervision, through which children can recognize clear and consistent expectations that help them regulate their behavior)
  • Granting of autonomy (the extent to which parents support their children’s autonomy, i.e., the independence with which children are allowed to act on their own behalf and make decisions)¹⁵²
• negative parenting behaviors¹¹¹
  • Overreaction¹⁵³
  • Psychological control (intrusive and manipulative parental behaviors specifically aimed at controlling the child while exploiting the emotional parent-child relationship)
    • SMD 0.17 (meta-analysis, k = 4, N = 682)²
  • Strict control (a range of highly destructive parenting practices, such as psychological and physical punishment, neglect, and overbearing behavior)
    • SMD 0.19 (meta-analysis, k = 7, N = 3,407)²
  • Abuse
    • physical and emotional abuse, neglect, sexual abuse, or unspecified abuse: a 627% increased risk of ADHD (meta-analysis, k = 6, N = 1,878)²
    • Physical abuse: SMD 0.39 (meta-analysis, k = 4, N = 1,406)²

There are feedback effects involved:¹⁵⁴

• The child’s genetically determined impulsivity and social withdrawal contributed to a strict parenting style
• The child’s genetically determined cheerful disposition fostered parental warmth
• Genetically influenced traits in children either amplified positive parental influences on the child’s development or protected the children from strict parenting

With regard to ADHD as well, significant effects of parental parenting styles on the child’s ADHD symptoms were found.

• ADHD symptoms in the adoptive mother and hostile parenting behaviors contributed to ADHD symptoms in the child, even in adoptive families¹⁵⁵
• The child’s genetically determined ADHD-related temperament traits fostered hostility in genetically unrelated mothers, which in turn increased the child’s ADHD symptoms¹⁵⁵

13.2.6. Emotion-Focused vs. Problem-Focused Coping Strategies¶

100% of parents of children with ADHD or ASD (n = 212) used emotion-focused coping strategies, while 94.93% of parents of typically developing children used problem-focused coping strategies.¹⁵⁷

14. Maternal Stress During Childhood¶

Stress experienced by mothers of boys aged 5 to 13 with ADHD tended to increase their ADHD symptoms 12 months later and significantly worsened the children’s quality of life.¹⁵⁸ Parental stress generally correlated with increased ADHD symptoms in children.⁷
Maternal stress when the child was 4 years old was associated with low to moderate levels of the following in the child up to age 15:¹⁵⁹

• internalizing symptoms
• externalizing symptoms
• ADHD symptoms

Parents of children with ASD and ADHD reported significantly higher stress levels than parents of neurotypical children (M = 116.7 and M = 88.1, respectively, compared to M = 67.2).¹⁵⁷ It remains unclear whether this is a contributing cause or a consequence of the children’s ADHD, or whether it stems from the parents’ own dispositions, which genetically influenced the children’s risk for ASD or ADHD.

15. Family instability, constant arguments between the parents¶

High stress levels in the primary family are associated with an increased risk of ADHD.⁴⁵⁶⁷

Longitudinal studies also find that ADHD does not persist completely during childhood and adolescence and confirm that it frequently co-occurs with family and parenting problems.¹⁶² Conversely, strong family cohesion and social support have a protective effect against ADHD.¹⁶³

16. Parents’ reduced capacity for self-reflection on their role as parents¶

Lower levels of parental reflective functioning correlated with ADHD in children.⁹ Parental reflective functioning is defined as the ability of parents to reflect on their own experiences and their child’s inner mental experiences.

17. Maternal Nasal Allergy¶

Among children under 5 years of age, the risk of ADHD was 41% higher if the mother had a nasal allergy, although the result was just barely not statistically significant (p = 0.059).⁷¹

18. High blood pressure in the mother¶

Among children under 5 years of age, the risk of ADHD was 137% higher if the mother had high blood pressure (not statistically significant).⁷¹ The information was collected using the question, “Do you currently have hypertension diagnosed by a doctor?” According to the Taiwanese guidelines for the prevention and control of high blood pressure, a diagnosis requires at least three blood pressure measurements and the average of three separate measurements, taken at different times and consistently showing a systolic blood pressure of ≥ 140 mmHg or a diastolic blood pressure of ≥ 90 mmHg.⁷²

19. Family Factors Associated with a Reduced Risk of ADHD¶

Parents’ immigrant status is associated with a reduced risk of ADHD¹⁶⁴ within the first two generations.¹⁶⁵