Two stories came my way during the last month that I thought deserved a little bit of attention - both demonstrate the impact of the interpersonal environment on the developing brains of our children. In these two instances, the outcomes are not good.
A third story (from the end of July) shows the benefits of emotionally attuned parenting in alleviating stress and anxiety in children - parenting style needs to be tailored to the child's personality.
Enlarged Amygdala: Children of depressed mothers have a different brain
Science Codex | Posted On: August 15, 2011
Researchers think that brains are sensitive to the quality of child care, according to a study using ten year old children whose mothers exhibited symptoms of depression throughout their lives, and discovered that the children’s amygdala, a part of the brain linked to emotional responses, was enlarged.
Similar changes, but of greater magnitude, have been found in the brains of adoptees initially raised in orphanages. Personalized attention to children’s needs may be the key factor. “Other studies have shown that mothers feeling depressed were less sensitive to their children’s needs and were more withdrawn and disengaged,” explained Drs. Sophie Parent and Jean Séguin of Université de Montréal, who followed the children over the years.
Scientists have established that the amygdala is involved in assigning emotional significance to information and events, and it contributes to the way we behave in response to potential risks. The need to learn about the safety or danger of new experiences may be greater in early life, when we know little about the world around us.
Indeed, studies on other mammals, such as primates, show that the amygdala develops most rapidly shortly after birth. “We do not know if the enlargement that we have observed is the result of long-term exposure to lower quality care. But we show that growing up with a depressed mother is associated with enlarged amygdala.”
“Having enlarged amygdala could be protective and increase the probability of survival,” Lupien said. The amygdala may be protective through a mechanism that produces stress hormones known as glucocorticoids. The researchers noted that the glucocorticoids levels of the children of depressed mothers who participated in this study increased significantly when they were presented with unfamiliar situations, indicating increased reactivity to stress in those children.
Adults who grew up in similar circumstances as these children show higher levels of glucocorticoids and a greater glucocorticoid reaction when participating in laboratory stress tests. “What would be the long term consequences of this increased reactivity to stress is unknown at this point.”
Although this study cannot clarify the causes of enlarged amygdala, the researchers note that the adoption studies have also shown that children who were adopted earlier in life and into more affluent families than others did not have enlarged amygdala. “This strongly suggests that the brain may be highly responsive to the environment during early development and confirms the importance of early intervention to help children facing adversity,” Lupien said. “Initiatives such as prenatal and infancy nurse home visits and enriched day care environments could mitigate the effects of parental care on the developing brain.”
Séguin adds, “Future studies testing the effects of these preventive programs and observational studies involving children exposed to maternal depressive symptoms at different ages, and consequently for different lengths of time, should provide more insight into how this occurs, its long term consequences, and how it can be prevented.”
Financed in part by the John D. and Catherine T. MacArthur Foundation, the Canadian Institutes for Health Research, and Fonds de recherche en santé du Québec.
Lupiena, Parentd, Evanse, Tremblayc, Zelazo, et al. (2011, Aug. 15). Larger amygdala but no change in hippocampal volume in 10-year-old children exposed to maternal depressive symptomatology since birth. PNAS, www.pnas.org/cgi/doi/10.1073/pnas.1105371108
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Childhood maltreatment linked to long-term depression risk and poor response to treatment
People who have experienced maltreatment as children are twice as likely to develop both multiple and long-lasting depressive episodes as those without a history of childhood maltreatment, according to a new study
People who have experienced maltreatment as children are twice as likely to develop both multiple and long-lasting depressive episodes as those without a history of childhood maltreatment, according to a new study. The research, led by a team at King's College London Institute of Psychiatry also found that maltreated individuals are more likely to respond poorly to pharmacological and psychological treatment for depression.
The results, to be published in the American Journal of Psychiatry, have emerged from a combined analysis of 16 epidemiological studies involving more than 20,000 participants and of 10 clinical trials involving more than 3,000 participants.
Depression ranks among the most common psychiatric disorders worldwide, with one in ten children exposed to maltreatment including psychological, physical or sexual abuse or neglect. By 2020, depression is predicted to be the second leading contributor to the global burden of disease across all ages, according to the World Health Organisation. The societal impact of depression is largely accounted for by individuals who develop multiple and long-lasting depressive episodes.
Previous research has shown that maltreated individuals are more likely to show abnormalities in biological systems sensitive to psychological stress – such as the brain, the endocrine, and the immune system – both in childhood and in adult life, which could have important clinical implications.
Dr Andrea Danese, senior investigator of the study at King's says: 'Identifying those at risk of multiple and long-lasting depressive episodes is crucial from a public health perspective. The results indicate that childhood maltreatment is associated both with an increased risk of developing recurrent and persistent episodes of depression, and with an increased risk of responding poorly to treatment.
'Therefore prevention and early therapeutic interventions targeting childhood maltreatment could prove vital in helping prevent the major health burden owing to depression. Knowing that individuals with a history of maltreatment won't respond as well to treatment may also be valuable for clinicians in determining patients' prognosis.'
Dr Danese continues: 'The biological abnormalities associated with childhood maltreatment could potentially explain why individuals with a history of maltreatment respond poorly to treatment for depression.'
Individuals with a history of maltreatment are at elevated risk of mental illness throughout their lives. However, in order to understand how early experiences bring about mental illness, future research should explore biological changes associated with maltreatment before accumulation of multiple depressive episodes.
Dr Rudolf Uher, co-author of the paper, says: 'Our study has shown that antidepressant medication, psychological treatment and the combination of the two are less effective in those who have a history of childhood maltreatment. Whilst we still do not know exactly what type of treatment may improve their care, it may be that new treatments based on the biological vulnerabilities associated with childhood maltreatment could prove an exciting avenue for research.'
The research was supported by the UK MRC Social, Genetic & Developmental Psychiatry Centre (SGDP), and the Department of Child and Adolescent Psychiatry, both at the Institute of Psychiatry, King's College London. The authors are funded by the National Alliance for Research on Schizophrenia and Depression (NARSAD/Brain and Behavior Research Fund, USA), the Italian Ministry of University and Scientific Research, and the European Commission.
Valentina Nanni, V., Uher, R. & Danese, A. (2011, Aug. 14). Childhood maltreatment predicts unfavorable course of illness and treatment outcome in depression: A meta-analysis. American Journal of Psychiatry. doi:10.1176/appi.ajp.2011.11020335
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Kids' anxiety, depression halved when parenting styled to personalityCitation:
When it comes to rearing children, just about any parent will say that what works with one kid might not work with another. Parents use all sorts of strategies to keep kids from being cranky, grumpy, fearful or moody, while encouraging them to be independent and well-adjusted.
But which parenting styles work best with which kids? A study by University of Washington psychologists provides advice about tailoring parenting to children's personalities.
At the end of the three-year study, the psychologists found that the right match between parenting styles and the child's personality led to half as many depression and anxiety symptoms in school-aged children. But mismatches led to twice as many depression and anxiety symptoms during the same three years.
The study was published online Aug. 1 in the Journal of Abnormal Child Psychology.
"This study moves away from the one-size-fits-all approach to parenting, and gives specific advice to parents on how to mitigate their child's anxiety and depression," said Cara Kiff, lead author and psychology resident at the UW School of Medicine. "We're considering characteristics that make children vulnerable to anxiety and depression, and factoring in how that shapes how kids react to different parenting approaches."
"We hear a lot about over-involved parents, like 'tiger moms' and 'helicopter parents,'" said co-author Liliana Lengua, a UW psychology professor. "It is parents' instinct to help and support their children in some way, but it's not always clear how to intervene in the best way. This research shows that parenting is a balance between stepping in and stepping out with guidance, support and structure based on cues from kids."
Kiff, Lengua and Nicole Bush, a co-author and postdoctoral fellow at University of California, San Francisco's Center for Health and Community, studied interactions between 214 children and their mothers during interviews at home. An almost even mix of boys and girls participated in the study and were, on average, 9 years old when the study began.
The children and their mothers met with the researchers once a year. The researchers observed as the pairs discussed neutral topics, such as a recap of the day's events, and common problems, like conflicts over homework and chores. During the conversations, the researchers noted parenting styles, including warmth and hostility, and how much mothers allowed their child to guide the conversations – an autonomy-granting parenting style.
The researchers also measured the children's anxiety and depression symptoms and evaluated their personality characteristics. They paid particular attention to effortful control, the kids' abilities to regulate their own emotions and actions, which is associated with lower levels of depression and anxiety.
At the end of the three-year study, the researchers found that
Children with greater effortful control had fewer symptoms of anxiety and depression compared with other kids in the study, and those symptoms usually remained low regardless of parenting style.
When children were higher in effortful control but their parents used higher levels of guidance or provided little autonomy, those children showed higher levels of depression and anxiety.
Children with low effortful control had less anxiety when mothers provided more structuring and less autonomy.
Children low in effortful control doubled their anxiety symptoms if they had mothers who provided little control.
Lengua, who is also the director of the UW Center for Child and Family Well-Being, said the study shows how parents can use their child's personality and temperament to decide how much and what type of help to give. For some kids, particularly those who have trouble regulating their emotions, more help is good. But for kids who have pretty good self-control, too much parental control can lead to more anxiety and depression.
The results were somewhat surprising, Lengua said, because parents of children at this age are typically told to give their kids more autonomy as they learn to navigate social situations and make decisions about schedules and homework. This can butt against parents' intuition to assist kids through trickier situations.
"Parents should be there to help – but not take over – in difficult situations and help their children learn to navigate challenges on their own," Lengua said.
The National Institute of Mental Health funded the study.
Kiff, CJ, Lengua, LJ & and Bush, NR. (2011, Jul 30). Temperament variation in sensitivity to parenting: Predicting changes in depression and anxiety. Journal of Abnormal Child Psychology. DOI: 10.1007/s10802-011-9539-x