Keyes, K. M., Pratt, C., Galea, S., McLaughlin, K. A., Koenen, K. C., & Shear, M. K. (2014). The burden of loss: unexpected death of a loved one and psychiatric disorders across the life course in a national study. The American Journal of Psychiatry , 171 (8), 864–871.Abstract
OBJECTIVE: Unexpected death of a loved one is common and associated with subsequent elevations in symptoms of multiple forms of psychopathology. Determining whether this experience predicts novel onset of psychiatric disorders and whether these associations vary across the life course has important clinical implications. The authors examined associations of a loved one's unexpected death with first onset of common anxiety, mood, and substance use disorders in a population-based sample. METHOD: The relation between unexpected death of a loved one and first onset of lifetime DSM-IV disorders was estimated by using a structured interview of adults in the U.S. general population (analytic sample size=27,534). Models controlled for prior occurrence of any disorder, other traumatic experiences, and demographic variables. RESULTS: Unexpected death of a loved one was the most common traumatic experience and most likely to be rated as the respondent's worst, regardless of other traumatic experiences. Increased incidence after unexpected death was observed at nearly every point across the life course for major depressive episode, panic disorder, and posttraumatic stress disorder. Increased incidence was clustered in later adult age groups for manic episode, phobias, alcohol use disorders, and generalized anxiety disorder. CONCLUSIONS: The bereavement period is associated with elevated risk for the onset of multiple psychiatric disorders, consistently across the life course and coincident with the experience of the loved one's death. Novel associations between unexpected death and onset of several disorders, including mania, confirm multiple case reports and results of small studies and suggest an important emerging area for clinical research and practice.
McLaughlin, K. A., Sheridan, M. A., Alves, S., & Mendes, W. B. (2014). Child maltreatment and autonomic nervous system reactivity: identifying dysregulated stress reactivity patterns by using the biopsychosocial model of challenge and threat. Psychosomatic Medicine , 76 (7), 538–546.Abstract
{OBJECTIVE: Disruptions in stress response system development have been posited as mechanisms linking child maltreatment (CM) to psychopathology. Existing theories predict elevated sympathetic nervous system reactivity after CM, but evidence for this is inconsistent. We present a novel framework for conceptualizing stress reactivity after CM that uses the biopsychosocial model of challenge and threat. We predicted that in the context of a social-evaluative stressor, maltreated adolescents would exhibit a threat pattern of reactivity, involving sympathetic nervous system activation paired with elevated vascular resistance and blunted cardiac output (CO) reactivity. METHODS: A sample of 168 adolescents (mean age =14.9 years) participated. Recruitment targeted maltreated adolescents; 38.2% were maltreated. Electrocardiogram, impedance cardiography, and blood pressure were acquired at rest and during an evaluated social stressor (Trier Social Stress Test). Pre-ejection period (PEP), CO, and total peripheral resistance reactivity were computed during task preparation, speech delivery, and verbal mental arithmetic. Internalizing and externalizing symptoms were assessed. RESULTS: Maltreatment was unrelated to PEP reactivity during preparation or speech, but maltreated adolescents had reduced PEP reactivity during math. Maltreatment exposure (F(1,145) = 3.8-9.4
Gooding, H. C., Milliren, C., McLaughlin, K. A., Richmond, T. K., Katz-Wise, S. L., Rich-Edwards, J., & Austin, S. B. (2014). Child maltreatment and blood pressure in young adulthood. Child Abuse & Neglect , 38 (11), 1747–1754.Abstract
Adverse childhood experiences are associated with hypertension in older adults. This study assessed whether an association between child maltreatment and blood pressure is detectable in young adults and whether any association differs by sex or is modified by genetic polymorphisms known to be involved in stress sensitivity. We examined these patterns in a sample of 12,420 young adults ages 24-32 years who participated in Wave IV of the National Longitudinal Study of Adolescent Health. Participants retrospectively reported history of physical, emotional, or sexual abuse before age 18 years. Participants with a systolic blood pressure (SBP) >=140 mmHg or a diastolic blood pressure (DBP) >=90 mmHg were classified as hypertensive. We used sex-stratified linear and logistic regression models to assess associations between each type of childhood maltreatment and SBP, DBP, and hypertension. We created interaction terms to assess for effect modification of any relationship between maltreatment and blood pressure by sex or SLC64A genotype. Fifteen percent of females and 31.5% of males were hypertensive. Frequent physical abuse in childhood was reported by 5%, frequent emotional abuse by 12%, and any sexual abuse by 5%. No association was observed between abuse history and blood pressure in either males or females, nor was effect modification present by SLC64A genotype. Child maltreatment exposure was not associated with blood pressure or hypertension in young adults in this study. Future studies should investigate additional critical windows for the effect of child maltreatment on cardiovascular health.
McLaughlin, K. A., Sheridan, M. A., & Lambert, H. K. (2014). Childhood adversity and neural development: deprivation and threat as distinct dimensions of early experience. Neuroscience and Biobehavioral Reviews , 47, 578–591.Abstract
A growing body of research has examined the impact of childhood adversity on neural structure and function. Advances in our understanding of the neurodevelopmental consequences of adverse early environments require the identification of dimensions of environmental experience that influence neural development differently and mechanisms other than the frequently-invoked stress pathways. We propose a novel conceptual framework that differentiates between deprivation (absence of expected environmental inputs and complexity) and threat (presence of experiences that represent a threat to one's physical integrity) and make predictions grounded in basic neuroscience principles about their distinct effects on neural development. We review animal research on fear learning and sensory deprivation as well as human research on childhood adversity and neural development to support these predictions. We argue that these previously undifferentiated dimensions of experience exert strong and distinct influences on neural development that cannot be fully explained by prevailing models focusing only on stress pathways. Our aim is not to exhaustively review existing evidence on childhood adversity and neural development, but to provide a novel framework to guide future research.
Sumner, J. A., McLaughlin, K. A., Walsh, K., Sheridan, M. A., & Koenen, K. C. (2014). CRHR1 genotype and history of maltreatment predict cortisol reactivity to stress in adolescents. Psychoneuroendocrinology , 43, 71–80.Abstract
This study examined the contributions of a polymorphism of the corticotropin-releasing hormone receptor type I (CRHR1) gene (rs110402) and a history of child maltreatment–alone and in interaction–to patterns of cortisol reactivity in adolescents. Adolescents between the age of 13 and 17 years with (n=61) and without (n=97) a history of child maltreatment were exposed to the Trier Social Stress Test (TSST). Salivary cortisol was assessed at baseline, and 15 and 30 min after the start of the speech portion of the TSST. Saliva samples for genotyping rs110402 also were collected. Adolescents with one or more G alleles of rs110402, relative to A allele homozygotes, and those exposed to maltreatment, relative to non-exposed adolescents, exhibited blunted cortisol reactivity to the TSST (although these associations approached, but did not reach, the level of statistical significance when accounting for underlying population structure in our racially and ethnically diverse sample). There was also a trend for a stronger child maltreatment association with cortisol hypo-reactivity among G allele carriers, but this association was not statistically significant. Findings suggest that CRHR1 variation may moderate the downstream effects of child maltreatment on HPA axis function, and implications for understanding mechanisms of risk associated with early adversity are discussed.
Karam, E. G., Friedman, M. J., Hill, E. D., Kessler, R. C., McLaughlin, K. A., Petukhova, M., Sampson, L., et al. (2014). Cumulative traumas and risk thresholds: 12-month PTSD in the World Mental Health (WMH) surveys. Depression and Anxiety , 31 (2), 130–142.Abstract
BACKGROUND: Clinical research suggests that posttraumatic stress disorder (PTSD) patients exposed to multiple traumatic events (TEs) rather than a single TE have increased morbidity and dysfunction. Although epidemiological surveys in the United States and Europe also document high rates of multiple TE exposure, no population-based cross-national data have examined this issue. METHODS: Data were analyzed from 20 population surveys in the World Health Organization World Mental Health Survey Initiative (n = 51,295 aged 18+). The Composite International Diagnostic Interview (3.0) assessed 12-month PTSD and other common DSM-IV disorders. Respondents with 12-month PTSD were assessed for single versus multiple TEs implicated in their symptoms. Associations were examined with age of onset (AOO), functional impairment, comorbidity, and PTSD symptom counts. RESULTS: 19.8% of respondents with 12-month PTSD reported that their symptoms were associated with multiple TEs. Cases who associated their PTSD with four or more TEs had greater functional impairment, an earlier AOO, longer duration, higher comorbidity with mood and anxiety disorders, elevated hyperarousal symptoms, higher proportional exposures to partner physical abuse and other types of physical assault, and lower proportional exposure to unexpected death of a loved one than cases with fewer associated TEs. CONCLUSIONS: A risk threshold was observed in this large-scale cross-national database wherein cases who associated their PTSD with four or more TEs presented a more "complex" clinical picture with substantially greater functional impairment and greater morbidity than other cases of PTSD. PTSD cases associated with four or more TEs may merit specific and targeted intervention strategies.
Sheridan, M. A., & McLaughlin, K. A. (2014). Dimensions of early experience and neural development: deprivation and threat. Trends in Cognitive Sciences , 18 (11), 580–585.Abstract
Over the past decade, a growing area of research has focused on adverse childhood experiences (ACEs) and their impacts on neural and developmental outcomes. Work in the field to-date has generally conceptualized ACEs in terms of exposure to stress while overlooking the underlying dimensions of environmental experience that may distinctly impact neural development. Here, we propose a novel framework that differentiates between deprivation (absence of expected cognitive and social input) and threat (presence of a threat to one's physical integrity). We draw support for the neural basis of this distinction from studies on fear learning and sensory deprivation in animals to highlight potential mechanisms through which experiences of threat and deprivation could affect neural structure and function in humans.
Stein, D. J., McLaughlin, K. A., Koenen, K. C., Atwoli, L., Friedman, M. J., Hill, E. D., Maercker, A., et al. (2014). DSM-5 and ICD-11 definitions of posttraumatic stress disorder: investigating "narrow" and "broad" approaches. Depression and Anxiety , 31 (6), 494–505.Abstract
BACKGROUND: The development of the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5) and ICD-11 has led to reconsideration of diagnostic criteria for posttraumatic stress disorder (PTSD). The World Mental Health (WMH) Surveys allow investigation of the implications of the changing criteria compared to DSM-IV and ICD-10. METHODS: WMH Surveys in 13 countries asked respondents to enumerate all their lifetime traumatic events (TEs) and randomly selected one TE per respondent for PTSD assessment. DSM-IV and ICD-10 PTSD were assessed for the 23,936 respondents who reported lifetime TEs in these surveys with the fully structured Composite International Diagnostic Interview (CIDI). DSM-5 and proposed ICD-11 criteria were approximated. Associations of the different criteria sets with indicators of clinical severity (distress-impairment, suicidality, comorbid fear-distress disorders, PTSD symptom duration) were examined to investigate the implications of using the different systems. RESULTS: A total of 5.6% of respondents met criteria for "broadly defined" PTSD (i.e., full criteria in at least one diagnostic system), with prevalence ranging from 3.0% with DSM-5 to 4.4% with ICD-10. Only one-third of broadly defined cases met criteria in all four systems and another one third in only one system (narrowly defined cases). Between-system differences in indicators of clinical severity suggest that ICD-10 criteria are least strict and DSM-IV criteria most strict. The more striking result, though, is that significantly elevated indicators of clinical significance were found even for narrowly defined cases for each of the four diagnostic systems. CONCLUSIONS: These results argue for a broad definition of PTSD defined by any one of the different systems to capture all clinically significant cases of PTSD in future studies.
Kessler, R. C., Rose, S., Koenen, K. C., Karam, E. G., Stang, P. E., Stein, D. J., Heeringa, S. G., et al. (2014). How well can post-traumatic stress disorder be predicted from pre-trauma risk factors? An exploratory study in the WHO World Mental Health Surveys. World psychiatry: official journal of the World Psychiatric Association (WPA) , 13 (3), 265–274.Abstract
Post-traumatic stress disorder (PTSD) should be one of the most preventable mental disorders, since many people exposed to traumatic experiences (TEs) could be targeted in first response settings in the immediate aftermath of exposure for preventive intervention. However, these interventions are costly and the proportion of TE-exposed people who develop PTSD is small. To be cost-effective, risk prediction rules are needed to target high-risk people in the immediate aftermath of a TE. Although a number of studies have been carried out to examine prospective predictors of PTSD among people recently exposed to TEs, most were either small or focused on a narrow sample, making it unclear how well PTSD can be predicted in the total population of people exposed to TEs. The current report investigates this issue in a large sample based on the World Health Organization (WHO)'s World Mental Health Surveys. Retrospective reports were obtained on the predictors of PTSD associated with 47,466 TE exposures in representative community surveys carried out in 24 countries. Machine learning methods (random forests, penalized regression, super learner) were used to develop a model predicting PTSD from information about TE type, socio-demographics, and prior histories of cumulative TE exposure and DSM-IV disorders. DSM-IV PTSD prevalence was 4.0% across the 47,466 TE exposures. 95.6% of these PTSD cases were associated with the 10.0% of exposures (i.e., 4,747) classified by machine learning algorithm as having highest predicted PTSD risk. The 47,466 exposures were divided into 20 ventiles (20 groups of equal size) ranked by predicted PTSD risk. PTSD occurred after 56.3% of the TEs in the highest-risk ventile, 20.0% of the TEs in the second highest ventile, and 0.0-1.3% of the TEs in the 18 remaining ventiles. These patterns of differential risk were quite stable across demographic-geographic sub-samples. These results demonstrate that a sensitive risk algorithm can be created using data collected in the immediate aftermath of TE exposure to target people at highest risk of PTSD. However, validation of the algorithm is needed in prospective samples, and additional work is warranted to refine the algorithm both in terms of determining a minimum required predictor set and developing a practical administration and scoring protocol that can be used in routine clinical practice.
Slopen, N., McLaughlin, K. A., & Shonkoff, J. P. (2014). Interventions to improve cortisol regulation in children: a systematic review. Pediatrics , 133 (2), 312–326.Abstract
Childhood adversity is associated with physiologic dysregulation across multiple biological systems; however, relatively little is known about whether these changes are reversible with intervention. The objective of this review was to examine evidence for the effectiveness of interventions to promote healthy cortisol regulation in children. We selected articles from English-language publications in PubMed and EBSCO databases through 2012. Two independent reviewers assessed articles against eligibility criteria. Eligible studies were randomized controlled or quasi-experimental studies designed to improve relationships, environments, or psychosocial functioning in children and examined cortisol as an outcome. We identified 19 articles. There was substantial heterogeneity across studies with regard to age, selection criteria, intervention design, cortisol assessment, and follow-up duration. Eighteen of the 19 articles reported at least 1 difference in baseline cortisol, diurnal cortisol, or cortisol responsivity between intervention and control participants. Importantly, however, there was remarkable inconsistency with regard to how the interventions influenced cortisol. Therefore, studies that included a low-risk comparison group (n = 8) provided critical insight, and each found some evidence that postintervention cortisol levels in the intervention group approximated the low-risk comparison group and differed from children receiving usual care. In conclusion, existing studies show that cortisol activity can be altered by psychosocial interventions. These findings are promising, not only because they indicate physiologic plasticity that can be leveraged by interventions but also because they suggest it may be possible to repair regulatory systems after childhood adversity, which could inform strategies for reducing health disparities and promoting lasting improvements in health.
Busso, D. S., McLaughlin, K. A., & Sheridan, M. A. (2014). Media exposure and sympathetic nervous system reactivity predict PTSD symptoms after the Boston marathon bombings. Depression and Anxiety , 31 (7), 551–558.Abstract
BACKGROUND: Terrorist attacks have been shown to precipitate posttraumatic stress disorder (PTSD) symptomatology in children and adolescents, particularly among youths with high exposure to media coverage surrounding such events. Media exposure may be particularly likely to trigger PTSD symptoms in youths with high physiological reactivity to stress or with prior psychopathology or exposure to violence. We examined the interplay between media exposure, preattack psychopathology, autonomic nervous system (ANS) reactivity, and prior violence exposure in predicting PTSD symptom onset following the terrorist attack at the 2013 Boston Marathon. METHODS: A community sample of 78 adolescents (mean age = 16.7 years, 65% female) completed a survey about the bombings, including media exposure to the event and PTSD symptoms. All respondents participated in a study assessing psychopathology prior to the attack, and sympathetic and parasympathetic reactivity to a laboratory-based stressor was assessed in a subset (N = 44) of this sample. We examined the associations of media exposure, ANS reactivity, preattack psychopathology, and prior violence exposure with onset of PTSD symptoms related to the bombings. RESULTS: Media exposure, preattack psychopathology, and prior violence exposure were associated with PTSD symptoms. Moreover, media exposure interacted with sympathetic reactivity to predict PTSD symptom onset, such that adolescents with lower levels of sympathetic reactivity developed PTSD symptoms only following high exposure to media coverage of the attack. CONCLUSIONS: We provide novel evidence that physiological reactivity prior to exposure to an unpredictable traumatic stressor predicts PTSD symptom onset. These findings have implications for identifying youths most vulnerable to PTSD following wide-scale trauma.
Aldao, A., McLaughlin, K. A., Hatzenbuehler, M. L., & Sheridan, M. A. (2014). The Relationship between Rumination and Affective, Cognitive, and Physiological Responses to Stress in Adolescents. Journal of Experimental Psychopathology , 5 (3), 272–288.Abstract
Although previous studies have established that rumination influences responses to stressful life events, the mechanisms underlying this relationship remain inadequately understood. The current study examines the relationship between trait rumination and affective, cognitive, and physiological responses to a standardized laboratory-based stressor in adolescents. A community-based sample of adolescents (N = 157) aged 13-17 completed the Trier Social Stress Test (TSST). Affective, cognitive, and physiological responses were obtained before, during, and after the TSST. Adolescents who engaged in habitual rumination experienced greater negative affect and more negative cognitive appraisals in response to the TSST than adolescents with lower levels of rumination. Rumination was unrelated to heart rate reactivity, but predicted slower heart rate recovery from the TSST, indicating that rumination might be specifically associated with physiological recovery from stress. Rumination is associated with negative affective, cognitive, and physiological responses following stressors, suggesting potential mechanisms through which it might increase risk for psychopathology.
McLaughlin, K. A., Aldao, A., Wisco, B. E., & Hilt, L. M. (2014). Rumination as a transdiagnostic factor underlying transitions between internalizing symptoms and aggressive behavior in early adolescents. Journal of Abnormal Psychology , 123 (1), 13–23.Abstract
The high degree of comorbidity among mental disorders has generated interest in identifying transdiagnostic processes associated with multiple types of psychopathology. Susan Nolen-Hoeksema conceptualized rumination as one such transdiagnostic process associated with depression, anxiety, substance abuse, binge eating, and self-injurious behavior. The degree to which rumination accounts for the co-occurrence of internalizing and externalizing psychopathology, however, has never been tested. We used a sample of early adolescents (N = 1,065) assessed at 3 time points spanning 7 months to examine (a) the reciprocal prospective associations between rumination and aggressive behavior in adolescents, (b) whether rumination explained the longitudinal associations of aggressive behavior with depression and anxiety symptoms, and (c) gender differences in these associations. Rumination predicted increases over time in aggressive behavior, and aggression was associated with increases in rumination over time only for boys. Rumination fully mediated the longitudinal association of aggression with subsequent anxiety symptoms and of both depression and anxiety symptoms with subsequent aggression in boys but not girls. Rumination did not explain the association between aggression and subsequent depressive symptoms for either boys or girls. These findings provide novel evidence for the role of rumination as a transdiagnostic factor underlying transitions between internalizing and externalizing symptoms among males during early adolescence. Interventions aimed at reducing rumination may have beneficial influences on multiple forms of psychopathology and on the development of comorbidity. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
Everett, B. G., Rosario, M., McLaughlin, K. A., & Austin, S. B. (2014). Sexual orientation and gender differences in markers of inflammation and immune functioning. Annals of Behavioral Medicine: A Publication of the Society of Behavioral Medicine , 47 (1), 57–70.Abstract
BACKGROUND: Sexual minorities have documented elevated risk factors that can lead to inflammation and poor immune functioning. PURPOSE: This study aims to investigate disparities in C-reactive protein (CRP) and Epstein-Barr virus (EBV) by gender and sexual orientation. METHODS: We used the National Longitudinal Study of Adolescent Health to examine disparities in CRP (N = 11,462) and EBV (N = 11,812). RESULTS: Among heterosexuals, women had higher levels of CRP and EBV than men. However, sexual minority men had higher levels of CRP and EBV than heterosexual men and sexual minority women. Lesbians had lower levels of CRP than heterosexual women. CONCLUSIONS: Gender differences in CRP and EBV found between men and women who identify as 100 % heterosexual were reversed among sexual minorities and not explained by known risk factors (e.g., victimization, alcohol and tobacco use, and body mass index). More nuanced approaches to addressing gender differences in sexual orientation health disparities that include measures of gender nonconformity and minority stress are needed.
Hatzenbuehler, M. L., Slopen, N., McLaughlin, K. A., & McLaughlin, K. A. (2014). Stressful life events, sexual orientation, and cardiometabolic risk among young adults in the United States. Health Psychology: Official Journal of the Division of Health Psychology, American Psychological Association , 33 (10), 1185–1194.Abstract
{OBJECTIVE: The goal of the present study was to examine whether sexual minority young adults are more vulnerable to developing cardiometabolic risk following exposure to stressful life events than heterosexual young adults. METHOD: Data came from the National Longitudinal Study for Adolescent Health (Shin, Edwards, & Heeren, 2009; Brummett et al., 2013), a prospective nationally representative study of U.S. adolescents followed into young adulthood. A total of 306 lesbian, gay, and bisexual (LGB) respondents and 6,667 heterosexual respondents met inclusion criteria for this analysis. Measures of cumulative stressful life events were drawn from all 4 waves of data collection; sexual orientation and cardiometabolic biomarkers were assessed at Wave 4 (2008-2009). RESULTS: Gay/bisexual men exposed to 1-2 ($\beta$ = 0.71
Hatzenbuehler, M. L., & McLaughlin, K. A. (2014). Structural stigma and hypothalamic-pituitary-adrenocortical axis reactivity in lesbian, gay, and bisexual young adults. Annals of Behavioral Medicine: A Publication of the Society of Behavioral Medicine , 47 (1), 39–47.Abstract
BACKGROUND: Youth exposed to extreme adverse life conditions have blunted cortisol responses to stress. PURPOSE: This study aims to examine whether growing up in highly stigmatizing environments similarly shapes stigmatized individuals' physiological responses to identity-related stress. METHODS: We recruited 74 lesbian, gay, and bisexual young adults (mean age = 23.68) from 24 states with varying levels of structural stigma surrounding homosexuality. State-level structural stigma was coded based on several dimensions, including policies that exclude sexual minorities from social institutions (e.g., same-sex marriage). Participants were exposed to a laboratory stressor, the Trier Social Stress Test (TSST), and neuroendocrine measures were collected. RESULTS: Lesbian, gay, and bisexual young adults who were raised in highly stigmatizing environments as adolescents evidenced a blunted cortisol response following the TSST compared to those from low-stigma environments. CONCLUSIONS: The stress of growing up in environments that target gays and lesbians for social exclusion may exert biological effects that are similar to traumatic life experiences.
McLaughlin, K. A., Alves, S., & Sheridan, M. A. (2014). Vagal regulation and internalizing psychopathology among adolescents exposed to childhood adversity. Developmental Psychobiology , 56 (5), 1036–1051.Abstract
Childhood adversity (CA) is strongly associated with youth psychopathology. Identifying factors that reduce vulnerability following CA is critical for developing preventive interventions. Vagal tone and vagal reactivity following psychosocial stressors might influence psychopathology among youths exposed to CA. We acquired heart period and impedance cardiography data to calculate respiratory sinus arrhythmia (RSA) and preejection period (PEP) from 157 adolescents aged 13-17 years at rest and during the Trier Social Stress Test (TSST). Internalizing and externalizing symptoms and multiple forms of CA were assessed. Resting RSA and RSA reactivity interacted with CA in predicting internalizing but not externalizing psychopathology; CA was unassociated with internalizing problems in adolescents with high resting RSA and RSA reactivity. No interactions were observed with PEP. High resting RSA predicted greater vagal rebound and accelerated heart rate recovery following the TSST, highlighting one potential mechanism underlying low internalizing symptoms following CA among youths with high vagal tone.
McLaughlin, K. A., Sheridan, M. A., Winter, W., Fox, N. A., Zeanah, C. H., & Nelson, C. A. (2014). Widespread reductions in cortical thickness following severe early-life deprivation: a neurodevelopmental pathway to attention-deficit/hyperactivity disorder. Biological Psychiatry , 76 (8), 629–638.Abstract
BACKGROUND: Children exposed to early-life psychosocial deprivation associated with institutional rearing are at markedly elevated risk of developing attention-deficit/hyperactivity disorder (ADHD). Neurodevelopmental mechanisms that explain the high prevalence of ADHD in children exposed to institutionalization are unknown. We examined whether abnormalities in cortical thickness and subcortical volume were mechanisms explaining elevations in ADHD among children raised in institutional settings. METHODS: Data were drawn from the Bucharest Early Intervention Project, a cohort of children raised from early infancy in institutions in Romania (n = 58) and age-matched community control subjects (n = 22). Magnetic resonance imaging data were acquired when children were aged 8 to 10 years, and ADHD symptoms were assessed using the Health and Behavior Questionnaire. RESULTS: Children reared in institutions exhibited widespread reductions in cortical thickness across prefrontal, parietal, and temporal regions relative to community control subjects. No group differences were found in the volume of subcortical structures. Reduced thickness across numerous cortical areas was associated with higher levels of ADHD symptoms. Cortical thickness in lateral orbitofrontal cortex, insula, inferior parietal cortex, precuneus, superior temporal cortex, and lingual gyrus mediated the association of institutionalization with inattention and impulsivity; additionally, supramarginal gyrus thickness mediated the association with inattention and fusiform gyrus thickness mediated the association with impulsivity. CONCLUSIONS: Severe early-life deprivation disrupts cortical development resulting in reduced thickness in regions with atypical function during attention tasks in children with ADHD, including the inferior parietal cortex, precuneus, and superior temporal cortex. These reductions in thickness are a neurodevelopmental mechanism explaining elevated ADHD symptoms in children exposed to institutional rearing.
Mclaughlin, K., Sheridan, M., & Nelson, C. (2013). Adverse Childhood Experiences and Brain Development: Neurobiological Mechanisms linking the Social Environment to Psychiatric Disorders. In K. Koenen, S. Rudenstine, E. Susser, & S. Galea (Ed.), A Life Course Approach to Mental Disorders (pp. 249-258) . Oxford University Press. PDF
Mclaughlin, K. (2013). The developmental psychopathology of major depression. In M. Power (Ed.), Mood Disorders: A Handbook of Science and Practice (2nd ed. pp. 107-141) . Wiley-Blackwell. PDF