Can we identify biological markers of risk and resilience related to the intergenerational transmission of risk?

Andrea Gonzalez Offord Centre for Child Studies Department of Psychiatry & Behavioural Neurosciences

(Affifi et al., 2011; Cicchetti & Toth, 2005; Gilbert et al., 2009; Gonzalez, 2013)

Child Outcomes

G1

G2

Macrosystem

Exosystem

Mesosystem

Microsystem

Early Adversity

Mechanism of Transmission

• In animals: proposed mechanisms are physiological and include changes in:

Hypothalamic-pituitary-adrenal (HPA) function, serotonergic function and changes in brain plasticity (Burton et al., 2007; Kaffman & Meaney, 2007; Maestripieri et al., 2007)

• In humans: proposed mechanisms have originated from social learning or attachment and include:

– Observational learning, role-modeling, and transmission via internal representations (Pullatz et al., 2004; Serbin & Karp, 2004; van IJzendoorn, 1992)

Proposed Model in Humans

Stress System: the Hypothalamic-Pituitary Adrenal (HPA) axis

Executive Function

Wisconsin Card Sorting Test

Stroop/ Color-Word Inhibition

Set shifting/Cognitive Flexibility

Tower Test

Spatial planning/inhibition

Spatial span/digit span

Maternal early adversity

HPA function

Executive function

Maternal sensitivity

0.22** -0.22*

0.22*

-0.33**

*p<.05 **p< .01 χ2= 5.53; CFI = .98, RMSEA = .06

Gonzalez et al., 2012 JAACAP

Why does this matter? Transmission beyond mom...?

Developing HPA axis is strongly influenced by social factors throughout infancy

In high-risk populations evidence of transmission of HPA activity to offspring: • Offspring of Holocaust survivors (with parental PTSD)

had significantly lower diurnal cortisol levels (Yehuda et al., 2006)

• Infants whose mothers developed PTSD after 9/11 had lower diurnal cortisol levels compared to infants with mothers without PTSD (Yehuda & Bierer, 2008)

Parenting and Infant Cortisol Reactivity

Atkinson et al., 2013; Psychoneuroendocrinology

Mothers and infants’ baseline cortisol levels were positively related, r = .53* and their slopes were positively related, r = .60*

Transmission of Executive Function?

3-months: Maternal history of childhood

maltreatment

8-months: Maternal executive

function and parenting

18-months:

Infant Cognition

3-years: Child

executive function

Child cognitive function: 18-months

F(6, 104) = 2.26, p <.05

Child Executive Function: 3 years

Summary

Gonzalez, Atkinson, & Fleming, 2009

Parenting Brain Recruits Multiple Systems

• Adaptive parenting requires a constellation of capacities including effective stress regulation, attentional control, emotion regulation and executive function.

Infant cues

EF performance

Early Adversity

• Recent imaging studies have implicated these same areas as vulnerable sites to the effects of early adversity, including the DLPFC, ACC, OFC, mPFC, the hippocampus and the amygdala (Hart & Rubia, 2012)

Summary

• Early adversity and its impact on biological systems may mediate or moderate deficits related to poor parenting and subsequent offspring outcomes

• Understanding the role that these systems plays may help in the understanding of the intergenerational transmission of risk

Intervention Implications • Psycho-educational

interventions is likely not be enough to improve parenting and child outcomes for all families

• Potential for innovative interventions to target underlying neurocognitive functions and stress system in parents and associated competencies in children

• Empirical question whether interventions should target these core capabilities explicitly or implicitly (Shonkoff & Fisher, 2014)

Acknowledgements: Collaborators, Staff, Students, and Participating Families

• Collaborators • Harriet MacMillan (McMaster) • Leslie Atkinson (Ryerson) • Susan Jack (McMaster) • Geoff Hall (McMaster) • Margaret McKinnon (McMaster) • Christine Wekerle (McMaster)

• Staff/students • Rebecca Lowe • Monica Ivan • Gillian-England Mason • Samantha Daniels

• All the mothers and infants who participated in the studies