6. Resilience, heightened sensitivity, genetic disposition and maternal care.

Not everyone is susceptible to ADHD.
ADHD can develop as a result of cortisolergic stress if the stress state is not terminated in time. The likelihood of this is increased in highly sensitive people¹ as well as in those with a genetic disposition due to hereditary / familial predisposition.

The neurological pathway is similar to that of post-traumatic stress disorder. In post-traumatic stress disorder, “highly stressful events alter sub-cortical centers of stress regulation and thus impair the regulation of subsequent stressors.”²

• 6.1. High parental care causes resilience
• 6.2. High oxytocin receptor density in the nucleus accumbens makes reslient to parental neglect
• 6.3. Other genes that correlate with resilience

6.1. High parental care causes resilience¶

Particularly caring maternal behavior, including intense licking and intensive care of the offspring, leads to a “neophilic” animal in rats that explores novel environments and reacts less emotionally, as well as a lower cortisol stress response in the HPA axis in novel situations.
In contrast, poor maternal care leads to a “neophobic” phenotype with increased emotional and HPA reactivity and less exploration of a novel situation.³
In addition, neophilic animals live an average of 200 days longer and appear to be less susceptible to cancer.⁴

6.2. High oxytocin receptor density in the nucleus accumbens makes reslient to parental neglect¶

High oxytocin receptor density in the nucleus accumbens caused increased resistance of newborns to neglect due to social isolation (a specific form of early childhood stress):⁵

• Animals with low oxytocin receptor density in the nucleus accumbens
  • Without neonatal neglect
    • Strong preference as adults to spend more time with their partner than with strangers
  • And neonatal neglect
    • No preference as an adult to spend more time with their partner than with strangers
• Animals with low oxytocin receptor density in the nucleus accumbens
  • Strong cuddle time preference for partner even with neonatal neglect

Blockade of the oxytocin receptor in the mPFC or nucleus accumbens (but not in the adjacent caudate nucleus or putamen) prevented the formation of a partner bond.⁶

6.3. Other genes that correlate with resilience¶

A meta-analysis found evidence that certain forms of the following genes correlate with resilience:⁷

• The serotonin transporter gene a. 5-HTTLPR in SLC6A4 and b. rs25531
  • For children
    • L/L or L’/L’ genotype
  • For adults
    • S/S or S’/S’ genotype
• The D4 dopamine receptor gene
  • C/C and C/T of rs1800955 n ¼ 1
  • 7r/7r and 4r/7r of VNTR (in exon III)
• The BDNF gene
  • Val/Val from rs6265
• The CRH receptor 1 gene
  • 1 of the 2 copies of the TAT haplotype of rs110402, rs242924 and rs7209436
• The G protein signaling 2 regulator gene (RGS2)
  • G/G from rs4606