Pediatric PTSD: Clinical, Forensic, and Diagnostic Understanding

Neurobiological Models of Pediatric PTSD

It has been shown in multiple studies that trauma has the potential to disrupt several normal neurodevelopmental processes in children and adolescents. At its core, PTSD can be thought of as resulting from a dysregulation of the neural networks that control the fear and stress response.⁴³ The dysregulation includes not only the critical structures of the hypothalamic–pituitary–adrenal (HPA) axis, but also the hippocampus, amygdala, prefrontal cortex and corpus callosum and the interconnections between these regions.^6,9,43 In addition neurotransmitter systems have been implicated in the pathogenesis of PTSD, including dopamine, norepinephrine, serotonin, GABA, and glutamate.^9,43

Neuroimaging of anatomical changes associated with PTSD is of particular importance in forensic evaluations, as it can be used in court to assert that direct physical consequences of a traumatic event have occurred. In the neuroimaging of adults with PTSD the most consistent anatomical finding has been a reduction of hippocampal volume, which has been associated with deficits in verbal declarative memory.^9,44 In children however, most imaging studies have demonstrated no change in hippocampal volume compared with controls after exposure to trauma.⁴⁴ More recent longitudinal studies have found that the severity of PTSD and cortisol levels predicted volume reductions of the hippocampus over a 12- to 18-month interval.⁴⁵ These two findings, taken together, have led to the hypothesis that prolonged, excessive exposure to cortisol caused by trauma leads to neuronal death and a reduction in volume of the hippocampus over time, which becomes increasingly visible on imaging as adulthood approaches.^6,44,46

One of the most robust and replicated findings from structural imaging of PTSD in youth is the reduced cross-sectional area and connectivity of the corpus callosum.^44,47 Three recent studies have demonstrated a relationship between particular types of trauma and changes in specific areas of the sensory cortex.^48,–,50 Collectively, these studies seem to show that differing perceptual modalities can affect different parts of the sensory cortex. For example, seeing a trauma leads to changes in the visual cortex, whereas hearing something traumatic alters the auditory cortex.

Multiple other structural and functional abnormalities have been demonstrated on imaging after traumatic exposure. Pituitary volume seen on MRI in pubertal and postpubertal youth with a history of maltreatment was significantly larger than in controls.⁵¹ Studies in traumatized adults have found a hyperactivation of the amygdala in response to threatening words or faces compared with controls, which has been replicated in a functional fMRI study in youth presented with angry expressions.⁵² Abnormalities in neuronal metabolism in the medial prefrontal cortex have also been demonstrated on proton magnetic resonance spectroscopy (MRS),⁵³ as have differences in the activity of the frontal and prefrontal cortex on fMRI in traumatized adolescents.⁵⁴ Multiple studies have shown reductions in total cerebral volume in youth with PTSD or chronic trauma.⁴⁴ This observation has not been reported in adults and may represent a finding unique to children and adolescents.

Dimensional Models of Pediatric PTSD

Earlier conceptual frameworks viewed PTSD as a categorical entity in which a child either had PTSD, or did not. In this view, those individuals who met criteria for the type of traumatic event, specific symptoms, duration, and impairment, as defined by the DSM, were considered to be demonstrating a pathological syndrome. Those with posttraumatic symptoms that were present to a lesser extent did not exceed the diagnostic threshold and instead were lumped into the category of having a “normal” reaction to an extreme stressor that did not warrant diagnostic categorization.⁵⁵ However, evidence suggests that this paradigm is not correct. For children and adolescents with these subthreshold symptoms, it has been demonstrated that their levels of impairment and distress are not significantly different from those who do meet full criteria for PTSD.⁵⁶ These findings collectively demonstrate not only the need to recognize and treat these subthreshold symptoms in youth, as they are associated with significant distress and comorbidity, but also that, as with adults, the posttraumatic response is one that is graded and continuous.

In considering a wider range of posttraumatic responses in children and adolescents, opinion on what may constitute a precipitating event has been refined. The limits of the DSM-IV A2 criteria, particularly for young children, have been long recognized.^15,57 It has been found that, whereas “high-magnitude” events, such as child abuse or accidents, are clearly predictive of developing PTSD, “low-magnitude” events, such as deaths or losses, occur more commonly and are more likely to lead to posttraumatic symptoms in children because of their higher frequency of occurrence.⁵⁸ It has been shown that low-magnitude events such as the death of a loved one, parental separation, and breakup with a best friend or romantic interest, accounted for two-thirds of cases that resulted in painful recall and half of cases of subclinical PTSD.⁵⁹ Of note, in that study, although distress as measured by the presence of symptoms was clearly evident, very few participants met the criteria for full PTSD. In a forensic allegation of PTSD allegedly resulting from paternal sexual abuse in which one of the authors provided expert testimony, in court the child smiled and waved at the defendant. She had on numerous occasions stated in therapy that she missed her father and was not afraid of him. PTSD was diagnosed in the course of the forensic psychiatric evaluation, but was most likely secondary to the child's having been abruptly removed from her parents and placed in foster care.

PTSD is more appropriately viewed as dimensional and can exist as a continuum in children and adolescents. Taxometric analysis has illustrated this in the adult population, as well as more recently in adolescents.^55,60 A dimensional structure suggests the presence of an additive etiology for PTSD in children and adolescents, which would mean that no single genetic or environmental factor singularly leads it to develop,⁵⁵ which is at odds with the categorical definition used by the DSM-IV.¹³

Developmental Models of Pediatric PTSD

Very young children have much different cognitive, emotional, language, and memory capabilities from those of school age children or adolescents, who in turn are also developmentally distinct from adults. PTSD entered the DSM-III in 1980,⁶¹ but it was not until the DSM-III-R⁶² that the American Psychiatric Association first recognized that children's reactions to trauma can differ from an adult's. Each of the subsequent editions and revisions of the DSM have incorporated developmental considerations into the PTSD criteria, which has paralleled advances in understanding of development, neurobiology, and the natural history of pediatric PTSD, culminating in the changes made to the DSM-5. The necessity of incorporating a development perspective into diagnostic criteria has been driven by the need to diagnose PTSD more accurately across the age spectrum, as well as to tailor interventions, inform mental health policy, and enhance research efforts.

In considering developmental stages, posttraumatic symptoms can be manifested differently in four age clusters: preschool children, school-age children, adolescents, and adults. As outlined by Salmon and Bryant,¹⁶ factors that need to be incorporated in understanding a child's response to trauma include memory encoding and retrieval, his knowledge base, language capabilities, and emotion regulation. Each of these shapes the posttraumatic response and is dependent on age and developmental stage.

A child's knowledge base and language development influence how they interpret, encode, and appraise any event committed to memory. Younger children encode memories with less detail and are more likely to forget or distort aspects of an event than older children or adolescents. This tendency is part of the normal progression to adult memory processing and must not be misconstrued on evaluation as volitional or pathological. The limited knowledge base that younger children possess influences their emotional response, as events that are unlike their usual experiences will not be understood and may not be appraised as traumatic. This has the potential to be protective against distress and posttraumatic symptoms,^63,64 though the converse can also be true, and a lack of knowledge about a traumatic event can lead to greater distress and misinterpretation.^65,66

Language development at the time of encoding has a great effect on the degree to which an event can be verbally reported. Events that are experienced before adequate language has been acquired can be expressed behaviorally in play or interactions with other individuals, which has influenced the DSM-5 to incorporate a greater emphasis on behavioral features of PTSD for the preschool subtype.¹³ There is little evidence that preverbal memories can be reported verbally after language development.⁶⁷

The ability of children or adolescents to regulate their emotions after a trauma in part influences the degree of the stress response to it. As children age, the regulation of emotions is gradually transferred from parents and caretakers to internalized regulatory processes. Younger children may cope with a stressful situation by covering their eyes or ears, or by leaving,^68,69 whereas older children employ cognitive strategies, such as reappraisal, thought suppression, shifting attention, and cognitive avoidance.^69,–,71 More effective use of cognitive strategies with age imparts greater affective control and potential for resilience. Cognitive inhibition, which is the means by which intrusive or irrelevant information is kept from full consciousness, most likely does not develop until after age 10.¹⁶ With regard to reporting their feelings, children are not able to conceptualize complex or mixed emotions fully until approximately age 10.^72,73 Together these factors suggest that children do not have the potential to manage their thoughts or emotional responses to a trauma adequately until mid-childhood.¹⁶ Children in a more chaotic environment are more likely to develop posttraumatic sequelae.

Younger children lack strategies to retrieve information from memory spontaneously and require structure from adults to do so. For this reason, the younger the child, the less likely he is to initiate a conversation about the event or provide details about it.^74,75 Therapeutic discussion of the trauma is important in several regards, however. Failure to discuss the event will prevent the child from reappraising it or correcting misconceptions, and adult therapeutic support will not be available to help the child regulate his emotional responses more effectively.¹⁶ There are potential negative consequences to discussion as well, as memories in younger children can become distorted through suggestion or the passage of an extended period since the event. The repeated forensic interrogation by child protective services, law enforcement, plaintiff attorney interrogation, deposition, and trial testimony all can exacerbate PTSD symptoms and potentially lead to cognitive distress.

In the absence of more developed language skills and emotional regulation, the responses of preverbal children and preschoolers are largely characterized by mood, anxiety, and behavioral symptoms.⁷⁶ Even if they are too young to have an understanding of a stressor, the effect on their caretakers can significantly disrupt their routine and alter their support structure, leading to regression and detachment.⁷⁷ In infants less than 12 months of age, posttraumatic responses can be manifested as increased crying and irritability, separation anxiety, “freezing,” and an exaggerated startle response.⁷⁸ Toddlers tend to be more clingy, have disturbances of sleep (sleep terrors, nightmares), show a regression in behaviors and acquired skills, have increased temper tantrums, and may become selectively mute. By the fourth to sixth years, children begin to act out aggressively; they may regress by demonstrating nocturnal enuresis and loss of acquired speech, manifest somatic symptoms (headaches, stomachaches), or refuse to attend school. Younger children may be more susceptible to the posttraumatic symptom of re-experience (intrusive thoughts, images, or perceptions), because their memory is more visually and perceptually based.⁷⁹ The egocentrism that is a defining characteristic of younger children may lead them to feel responsible for causing a trauma, which results in more prominent guilt for them than in adolescents or adults.^70,80 Magical thinking has been associated with “omen formation,” in which young children believe that in retrospect “signs” of the traumatic event approaching could have been seen.^21,81 Young children are not able to manifest avoidance in the same way that older youth and adults can, simply because where they go and what they do are dictated by their adult caretakers.⁸²

School-age children (age 6 to puberty) have a greater ability to have empathy for others who were affected by a traumatic event, and can begin to engage in the “how” and “why” of a tragedy.⁸³ They exhibit more symptoms in their interactions with others, including social phobia and isolation, a fear of novel situations, separation anxiety, and repetitious traumatic play.⁷⁸ Posttraumatic play can seem joyless, and can involve re-enactions of the trauma, or drawings with traumatic content.³ Sleep disturbances and regression are seen, similar to younger children. Dreams may be vaguely formed and difficult for the child to describe. Children older than 6 may not demonstrate avoidant symptoms, but may instead develop new incident-specific fears that resemble phobias.⁸² They also may not have visual flashbacks or numbing symptoms.⁴² A sense of having a foreshortened future may have little validity in this and younger age groups, as they have little ability to conceptualize a time in the future. It has been noted that children may also have long periods of re-experiencing that alternates with periods of avoidance and numbing, instead of both occurring at the same time.⁸⁴

Although adolescents demonstrate symptoms of PTSD that are most similar to those of adults, aggressive outbursts and risk-taking behaviors are more salient in teenagers. Risk taking may take the form of substance use or high-risk sexual behaviors. Rebellion at home and school are common outcomes of trauma, as are school avoidance, depression, and anxiety.^34,78 Other frequently seen symptoms are loss of interest in previously enjoyed activities, withdrawal from family and peers, changes in life attitudes, eating disorders, somatic complaints, loss of affective control, personality changes, self-destructive and impulsive behaviors, and impaired relationships.^85,86

Adolescents who have been exposed to prolonged or multiple stressors may present with primarily dissociative symptoms, including depersonalization, derealization, self-injurious behaviors, and intermittent angry and aggressive outbursts.⁴² In clinical settings, parents often underestimate posttraumatic symptoms as adolescents may try to hide their reaction to a stressor for fear it may be abnormal or because they are attempting to protect others from distress.⁸⁷ However, it is important to note that this finding may not apply in the forensic context where there could be an incentive for parents to overreport posttraumatic symptoms.