Neurodevelopmental consequences and neuropsychological implications of traumatic stress
ABSTRACT
Childhood maltreatment is a significant risk factor for a host of psychiatric, developmental, medical, and neurocognitive conditions, often resulting in debilitating and long-term consequences. However, there is no available neuropsychological resource reviewing the literature on the associated neurocognitive deficits in children and adolescents. This review comprehensively examines the 23 prior studies that evaluated the intellectual, language, visual-spatial, memory, motor, and/or attention/executive functions in children and adolescents following an experience of childhood abuse and/or neglect. Neurocognitive impairments were frequently reported. Impairments in executive functions were the most frequent and severe reported impairments, although intelligence, language, visual-spatial skills, and memory are also at serious risk for compromised development following maltreatment. However, specific factors such as abuse/ neglect duration, severity, type, and timing during development were all associated with neurocognition. This indicates that these factors are of greater importance than just the presence of abuse/neglect in identifying risk for neurocognitive compromise. Such neurocognitive deficits appear to be a consequence to the known neurobiological and brain development abnormalities of this population, suggesting traumatic stress can be a potential cause of neurodevelopmental disorders. These findings have critical implications for the clinical practice and research involving children following childhood maltreatment and other types of traumatic stress.
Childhood maltreatment is defined as a child’s experience of sexual abuse, physical abuse, emotional abuse, or neglect (Crooks & Wolfe, 2007). Maltreatment occurs in one in eight U.S. children (12.5%) by 18 years of age (Wildeman et al., 2014). In 2012, U.S. state and local child protective services (CPS) estimated that 686,000 children experienced maltreatment, making it a national health concern (U.S. Department of Health and Human Services, Administration for Children, Youth, and Families, Children’s Bureau, 2013). Despite positive outcomes for some children and adolescents (Agaibi & Wilson, 2005; Carpenter & Stacks, 2009; Howell, 2011; Skopp, McDonald, Jouriles, & Rosenfield, 2007), childhood maltreatment is a significant risk factor for a host of psychiatric, developmental, medical, and neurocognitive conditions, often resulting in debilitating and long-term consequences (Crooks & Wolfe, 2007; De Bellis, Spratt, & Hooper, 2011; De Young, Kenardy, & Cobham, 2011; Kendall-Tackett, 2010; Pechtel and Pizzagalli, 2011; Wilson, Hansen, & Li, 2011).
Given the high rates and the growing research on long-term consequences, it was deemed critical to the field to provide a detailed review of the literature regarding the reported neurocognitive deficits in children following the experience of childhood maltreatment (i.e., sexual abuse, physical abuse, emotional/ verbal abuse, and neglect). Articles considered for inclusion in the current study were searched through the databases PubMed and PsycINFO. Inclusion criteria for this review: the study included only children and adolescents (ages 3–19 years), assessed 1 þneurocognitive domain (e.g., intelligence, memory, executive functions), and involved 1 þtype of childhood maltreatment (i.e., physical abuse, sexual abuse, emotional/verbal abuse, and/or neglect). The final review included 23 studies conducted from 1995–2015. In order to provide a comprehensive review of neurocognitive functioning, this review describes the literature on intelligence, executive functions, language, visual-spatial, memory, and motor/psychomotor domains. Prior neurocognitive study results are provided in Table 1, describing the utilized sample size, exclusion criteria, maltreatment/ control group demographics, type of abuse/neglect examined, neurocognitive domains assessed, relevant findings, and influence of psychiatric disorder diagnoses. To provide support for a neurodevelopmental conceptualization of childhood stress, we first briefly describe the neurobiological and brain development in traumatic stress research findings, and then provide the review of the neurocognitive impairments in children and adolescents following childhood maltreatment. Treatment and conceptualization implications are described in later sections.
Neurobiological response and brain development
While a comprehensive review of prior neurobiological and neuroimaging studies is well beyond the scope of this article, a basic understanding of such traumarelated consequences provides a framework within which to interpret neurocognitive findings. It is known that stress and trauma during childhood can cause severe disruption or alteration to the child’s ongoing neurodevelopmental process (Anda et al., 2006; Taber, Salpekar, Wong, & Hurley, 2011; Teicher, Tomoda, & Andersen, 2006). Within the developmental traumatology framework, originally proposed by De Bellis, a stressor such as childhood trauma activates the body’s biological stress response systems for potentially harmful prolonged periods of time (e.g., limbichypothalamic- pituitary-adrenal axis, sympathetic nervous system, and serotonin system; De Bellis, 2001; Teicher et al., 2003, 2006). This stress response causes a shift to occur from a process of brain development and growth (required during neurodevelopment) to one of preservation and survival (De Bellis & Zisk, 2014; Teicher et al., 2003). The neurobiological consequences of childhood stress include the elevated presence of catecholamines, corticotropin-releasing hormones, cortisol, and serotonin in the circulatory system (De Bellis et al., 2011; De Bellis & Zisk, 2014; Lupien et al., 2005; Teicher et al., 2003; Twardosz & Lutzker, 2010). As reviewed by De Bellis and Zisk (2014), such elevated levels of stress hormones and neurotransmitters during neurodevelopment may contribute to abnormal apoptosis or pruning, delays in myelination, inhibition of neurogenesis, or decreases in brain growth factors. Thus, the neurobiological response to childhood maltreatment places these children at risk for abnormal brain development.
Hypothesized to be secondary to the neurobiological stress response, researchers have identified structural and functional brain abnormalities in children and adolescents following childhood maltreatment. The majority of studies examining the influence of childhood stress on brain functioning have come from Carrion and colleagues (Carrion, Garrett, Menon, Weems, & Reiss, 2008; Carrion, Haas, Garrett, Song, & Reiss, 2010; Carrion et al., 2001; Carrion, Weems, & Reiss, 2007; Carrion, Weems, Richert, Hoffman, & Reiss, 2010; Richert, Carrion, Karchemskiy, & Reiss, 2006). Following childhood stress and trauma, such structural imaging studies of children and adolescents have identified decreased total brain volume (Carrion, Weems et al., 2010; De Bellis et al., 2002), as well as more specific findings in reduced volume in the prefrontal cortex and hippocampus (Carrion & Wong, 2012; Hart & Rubia, 2012), as well as amygdala and corpus callosum (Hart & Rubia, 2012). Functional imaging studies have also identified reduced hippocampal activation during memory-based tasks and reduced prefrontal cortex activation in inhibitory control tasks (Carrion & Wong, 2012; Hart & Rubia, 2012), while additional imaging studies have identified structural interregional connectivity abnormalities following childhood maltreatment (Hart & Rubia, 2012). Prior studies on the post-event cascade of neurobiological dysregulation and brain abnormalities provide strong evidence of an alteration to nervous system development following childhood stress and trauma (Carrion & Wong, 2012; De Bellis & Zisk, 2014).
Brian C. Kavanaugh, Jennifer A. Dupont-Frechette, Beth A. Jerskey & Karen A. Holler
To cite this article: Brian C. Kavanaugh, Jennifer A. Dupont-Frechette, Beth A. Jerskey & Karen A. Holler (2017) Neurocognitive deficits in children and adolescents following maltreatment: Neurodevelopmental consequences and neuropsychological implications of traumatic stress, Applied Neuropsychology: Child, 6:1, 64-78, DOI: 10.1080/21622965.2015.1079712 To link to this article: https://doi.org/10.1080/21622965.2015.1079712
