Pathways through which adult health can be compromised
We have all heard the saying “What doesn’t kill you makes you stronger” and “time heals all wounds”. These bits of common wisdom conjure a picture of traumatic experiences that, once overcome, result in greater levels of psychological, physical and emotional wellbeing. Although trials and tribulations can certainly build character, they can also create permanent biological, neurological and psychological compromise (Cozolino, 2002). The impact of traumatic events on infants and young children is often minimized in this way. It is ironic that during infancy and childhood, a time of the greatest vulnerability to the effects of trauma adults generally presume greater resilience (Perry, Pollard, Blakely, Baker, & Vigilante, 1995). The effects of early and severe trauma are widespread, devastating and difficult to treat (Cozolino, 2002; Giarratano, 2004a).
Childhood trauma can cause severe disturbances in the integration of sensory, emotional and cognitive information into a cohesive whole. This sets the stage for unfocused and irrelevant responses to subsequent stress (Cozolino, 2002; Streeck-Fischer & van der Kolk, 2000). For example, a lack of capacity for emotional self-regulation has been commonly observed in children who experience abuse and neglect (Streeck-Fischer & van der Kolk, 2000). Childhood trauma has a profound impact on the emotional, behavioural, cognitive, social and physical functioning of children (Perry et al., 1995). Among other impacts, a traumatised child may, over time, exhibit motor hyperactivity, anxiety, behavioural impulsivity, sleep problems, hypertension and a variety of neuro-endocrine abnormalities (Perry et al., 1995).
Similarly, adult survivors of childhood abuse have consistently identified impairments in adult physical and mental health in studies (Draper et al., 2007). Even though not everyone exhibits the same set of symptoms, or experiences the same intensity of problems, research shows that the long-term effects of child abuse are pervasive, across all areas of a survivor's world.
Although the association between childhood abuse and adult mental and physical health problems is well documented, less is known about the pathways through which health is compromised. An understanding of the effects of child abuse and neglect on a child’s physical (biological), cognitive, social, behavioural and emotional development helps make sense of their repercussions in adulthood. Pathways linking childhood abuse with adult health outcomes span emotional, behavioural, social, cognitive, and biological pathways.
Primary attachment to help modulate stress
There is evidence that caring and secure environments help to moderate the negative impact that stress places on the developing brain (Gunnar, 1998). Safety and bonding are crucial factors in the early construction of the brain. Childhood trauma can compromise core neural networks (Cozolino, 2002).
Normal childhood play and exploratory activity requires the presence of a familiar attachment figure to help modulate the child’s physiological arousal by providing a balance between soothing and stimulation (Streeck-Fischer & van der Kolk, 2000). Children feel secure when the caregiver provides consistent, warm and sensitive care (Davila & Levy, 2006). In secure environments, stressed children who seek and receive comfort from the primary caregiver, when comforted, return to their exploratory activity away from the parent (p. 989). The response of the caregiver not only protects the child from the effects of stressful situations by providing soothing when appropriate, but also enables the child to develop the biological framework for dealing with future stress (Schore, 1994; cited in Streeck-Fischer & van der Kolk, 2000). The acquisition of controllable stress reactions seems to result in central nervous system reactions that facilitate the capacity to deal with subsequent stresses.
In the absence of a secure base, children find they cannot rely on the primary caregiver for comfort and may become incapable of calming themselves down when threatened. In addition, if children are exposed to unmanageable stress and the caregiver does not help modulate the child’s arousal (as in situations of family violence) the child will be unable to organise his/her experiences in a coherent fashion (Streeck-Fischer & van der Kolk, 2000). If the child cannot regulate his/her emotional states, or rely on others to help: he/she will respond with fight or flight reactions. Cognitive understanding of events helps modulate emotions and enables the formulation of a flexible response. Both cognition and emotions are important. Children who are denied parental care or comfort for long periods of time, can suffer extreme mental and emotional deficits (Van Der Horst, LeRoy, & Van Der Veer, 2008).
Our first intimate or loving relationship is with our primary caregiver and this informs our expectations and patterns of behaviour (Harlow, 1958). For example, Bowlby (1969; 1973; 1980; 1988) identified a strong relationship between the pattern of attachment in young children and the patterns of their intimate relationships in later life. The negative core schema adopted by a survivor as a result of that first attachment fundamentally affects that survivor’s capacity to establish and sustain significant attachments throughout life. Survivors often experience conflictual relationships and chaotic lifestyles, frequently report difficulties forming adult intimate attachments and display behaviours that threaten and disrupt close relationships (Collins & Read, 1990; cited in Henderson, 2006).
Attachment theory, a theory of personality development emanating from John Bowlby's work (1988), can be used to explain the diverse array of negative outcomes in adult survivors of childhood abuse. Attachment theory suggests that early childhood relationships are internalised and inform an internal working model of the self, others and any relationships. The internal attachment model developed in childhood influences the patterns of relationship formation and attachment styles used in adult life. Difficulties associated with abuse-related attachment may be mirrored in relationships throughout a survivor's life. “Abusive acts thereby serve as an etiologic reservoir for the development of later psychological disorder” (Briere, 2002). Bowlby (1969, 1973, 1980, 1988) described four different patterns of attachment which determine children’s reactions in the presence or absence of their mother (or primary caregiver): secure attachments, ambivalent attachments, avoidant attachments and disorganised attachments.
- Secure attachments: ‘Securely attached’ children develop inner working models that see others as positively available and themselves as lovable, valued and socially effective (Bowlby1988). Overall, adults with secure attachments have effective strategies for regulating affect (Alexander & Anderson, 1994).
- Ambivalent attachments: ‘Ambivalent’ children experience parenting that is inconsistent, unreliable and emotionally neglectful. Persistent experiences of both emotional and physical neglect may lead children to suffer psychological distress resulting in feelings such as abandonment and rejection. The ambivalent child clings to the parent and exaggerates affect in order to take advantage of the intermittent responsiveness of their inconsistent parent. As an adult, the ‘ambivalent child’ may be described as clinging, jealous, obsessive, dependent, self-sacrificing, and describe love as a series of emotional highs and lows (Alexander & Anderson, 1994). ‘Ambivalent’ adults may be especially sensitive to the possibility of abandonment, rejection or isolation (Bowlby1988).
- Avoidant attachments: ‘Avoidant’ children experience parenting that is hostile, rejecting and controlling. They experience little warmth or love and their emotional needs remain largely unmet (Bowlby1988). Parents of the avoidant child are not necessarily consistently rejecting; however, their coldness and lack of responsiveness are sure to emerge at the point when the child needed help. The parent of the avoidant child may respond positively to the child’s autonomous behaviours but be misattuned to the child’s request for nurturance (Alexander & Anderson, 1994). Therefore, the learned response of the avoidant child is to hold back when feeling needy so as not to elicit even more rejection from the parent. This reluctance to express negative affect becomes internalised and may take form of compulsive self-reliance (Bowlby, 1969). As an adult the ‘avoidant child’ may be uncomfortable with intimacy, not confident about others’ availability, highly self-reliant, seen as hostile to others, easily frustrated with partners, and overtly denying of problems while exhibiting covert symptoms of anxiety, distress, and dysfunction (Alexander & Anderson, 1994).
- Disorganised attachments: The parent of the disorganised child tends to be frightening and/or frightened in his/her interactions with the child. Consequently, the disorganised child is in the untenable position of having to approach the very caretaker who is the source of the child’s anxiety and fearfulness (Alexander & Anderson, 1994). Unable to regulate their affect, these children adopt coping strategies such as dissociation when interacting with the parent. A study by Hertsgaard, Gunnar, Erickson, & Nachmias (1995) found that infants who exhibit disorganised attachment patterns have higher baseline cortisol levels. As adults ‘disorganised children’ they may see themselves as truly bad, responsible for their trauma and inherently flawed. They may experience significant distress, depression, and poor social adjustment (Alexander & Anderson, 1994).
Early patterns of attachment set the stage for how children process information and have powerful effects across the lifespan. Secure infants usually grow up being able to rely on both their emotions and thoughts to help them determine reactions to any given situation. Children in abusive environments may learn to either ignore what they feel (emotions) or what they perceive (cognition) (Streeck-Fischer & van der Kolk, 2000). For example, avoidant children ignore their distress and deal with their needs by relying upon the logic of what they can observe. Being able to inhibit their distress protects them from further harm. Ambivalent children may tend to grow up relying on what they are feeling, without much thought about the consequences of their actions. Confused about what they perceive, they tune into their feelings, at the expense of being able to think about the meaning of their experiences (Streeck-Fischer & van der Kolk, 2000).
Behavioural pathways link childhood abuse and adult health outcomes through health-related behaviours, such as smoking, substance abuse, overeating, high-risk sexual behaviour, and suicidal behaviour (Draper et al., 2007). In essence, survivors of child abuse are more likely to engage in high-risk behaviours that are deleterious to health (Draper et al., 2007).
The high risk behaviours (alcohol abuse etc.) observed in adult survivors can be viewed as ‘coping strategies’, initially adopted in childhood, to manage rejection, betrayal and abuse. The trauma of child abuse is said to stall thought development and behavioural responses. This can potentially lock survivors into the avoidant coping strategies they used during their childhood (such as detaching, denying, forgetting, dissociating, fantasising and withdrawing). The tendency to dissociate remains with the child as he/she grows into adulthood and impairs the development of adaptive coping mechanisms (Briere, 2002). As explained by Perry et al. (1995) if the threat is ongoing, as is often the case in child abuse situations, responses to threat become ‘traits’. As such, some of the impacts of childhood abuse observed in adult survivors can be the result of the coping strategies used by children in abusive environments (Henderson, 2006). The extreme coping strategies required to manage the extremes of traumatic stress can create serious symptoms (adaptations). The symptoms of psychological trauma include components of every diagnostic category as well as disruptions in identity, attachments, relationships, meaning and spirituality (Saakvinte, Gamble, Pearlman, & Tabor, 2000).
As explained by the women participants in a study by Van Loon and Kralik (2005a):
We spent our childhood maintaining a shroud of ‘silence and secrecy’ around our perverse experiences of child abuse. We coped by ‘suppressing memories’, ‘learning to forget’, ‘disengaging’, disassociating’, ‘isolating ourselves emotionally and relationally’, ‘trying to please everyone’, ‘trying to adapt’ and accommodate our ‘weird’ situation’, because there was ‘no escape anyway’. This allowed us to survive our childhood. But as we became teenagers we came ‘unstuck’. We knew we ‘didn’t fit in’. So we ‘numbed our rotten feelings’ by using alcohol, drugs and/or gambling.
Cognitive pathways include the beliefs and attitudes one adopts that shape daily life.
Some of the long-term impacts of child abuse may be grounded in the rejection and betrayal the child experienced, and their impact on cognitive patterns. As children, survivors of child abuse have often been betrayed, manipulated and silenced by the adult/s they should have been able to trust.
Most cognitive theories of development acknowledge that we organise the world according to emotion (Ayoub et al., 2006). In particular, we tend to have a natural bias towards the positive, especially when evaluating ourselves (Ayoub et al, 2006, p. 4). Children who experience severe and/or ongoing maltreatment will tend to develop a negative bias especially towards themselves (Ayoub et al, 2006). There is a tendency for children experiencing child abuse to attribute blame to themselves and to internalize abusive behaviours (Quas, Goodman, & Jones, 2003). These tendencies become cognitive patterns that can continue long into adulthood, and contribute to delays in the development of self-esteem and a healthy identity (van Loon & Kralik, 2005a).
Cognitive pathways are clearly intertwined with biological pathways. Children who are abused go immediately from (fearful) stimulus to fight/flight responses without learning from the experience because they can’t grasp what is happening (Streeck-Fischer & van der Kolk, 2000). Adult survivors’ responses to hostility or silence can often be misinterpreted as responses to current events rather than the conditioned reaction to reminders of the past they embody. Adult survivors tend to experience current stressors with an emotional intensity that belongs to the past, and has little value in the present (Streeck-Fischer & van der Kolk, 2000).
Social pathways link childhood abuse and its negative health outcomes through difficulties in establishing intimate relationships. The association between dysfunctional relationships and adverse mental and physical health outcomes has been frequently reported (Draper et al., 2007). Traumatic abuse in childhood can lead to chronic, negative expectations and perceptions around safety, trust, esteem, intimacy and control which are readily activated by interpersonal interactions in the present environment (Henderson, 2006).
Children exposed to environmental extremes in abusive situations and lacking an adult to provide continuity, can have a problem understanding themselves or others (Streeck-Fischer & van der Kolk, 2000). As they have no clear appreciation of who they or others are, such children do not know how to enlist other people as allies; people are perceived as sources of terror or gratification, but rarely fellow human beings with their own sets of needs and desires (Streeck-Fischer & van der Kolk, 2000). Unable to regulate their feelings, abused children are prone to scare other children (and in time adults) away and hence lack reliable playmates (Streeck-Fischer & van der Kolk, 2000). Parental child abuse not only traumatises children, but also deprives them of healing interactions (Cozolino, 2002).
Two-thirds of the long-term negative mental health effects of child abuse are related to poor educational, work choices and deficiencies in intimate relationships, with poor intimate relationships and career choices being amongst the most influential. This suggests that the social development pathway is significantly impacted by childhood abuse causing negative emotional or psychological outcomes in adulthood (Schilling, Aseltine, & Gore, 2007). A study by Schilling, Aseltine & Gore (2007) concluded that developing strong social supports was an important factor in ameliorating the effects of depression in a group of adult adolescents who had experienced severe abuse.
Neural development and social interactions are inextricably intertwined. As Tucker (1999, p. 199) says “for the human brain, the most important information for successful development is conveyed by the social rather than the physical environment” (cited in Streeck-Fischer & van der Kolk, 2000). For example, a study by Valentino, Cicchetti, Toth, & Rogosch (2006) found that mothers in abusive families were less available to play and interact socially with their infants even when they were 12 months of age. As a consequence, infants from abusive families demonstrated more imitative and less independent play than infants from non-abusing families.
Vulnerability to hyperarousal makes it difficult to tolerate uncertainty (Streeck-Fischer & van der Kolk, 2000). Avoiding novelty also leads to avoiding social contact. Hence, abused children miss out on the normal transmission of social skills (Streeck-Fischer & van der Kolk, 2000).
Seventy percent of our genetic structure is added after birth (Schore, 1994; cited in Cozolino, 2002). While the fundamental neuro-anatomical structure of the brain is genetically determined, the templates determining the categorisation and interpretation of experience within the limbic system and frontal lobes gradually develop as a child grows. Experience shapes the structure in which the brain is being organised (Streeck-Fischer & van der Kolk, 2000). Developmental experiences determine the organizational and functional status of the mature brain (Perry et al., 1995). A child’s interaction with the outside environment causes connections to form between brain cells (McLean Hospital, 2000). Because the developing brain organizes and internalizes new information in a use-dependent fashion, the more a child is in a state of hyper-arousal or dissociation, the more likely he/she is to have neuropsychiatric symptoms following trauma. The acute adaptive state can persist and cause maladaptive traits (Perry et al., 1995). In other words, continuing threat impacts the child’s developing brain and the responses to threat become ‘personality traits’ (Perry et al., 1995).
Impact on the physiology of the brain
Studies with survivors of childhood abuse have found:
- Impact on the cortex and limbic system
Research shows that children and adults with histories of child abuse can respond to minor triggers with a range of catastrophic reactions. This is because traumatised children (and adult survivors) become increasingly responsive to relatively minor stimuli as a result of decreased frontal lobe functioning (learning and problem solving) and increased limbic system (amygdala) sensitivity (impulsiveness) (Streeck-Fischer & van der Kolk, 2000).
- Decreased cortex activity
The cortex or the more rational, outer-layer of the brain is the seat of our thinking capacity. The cool, rational cortex is in constant communication with the amygdala and the hippocampus (the limbic system). The frontal lobes are situated in the cortex and are responsible for learning and problem solving. The capacity to learn from experience requires events to be registered in the prefrontal cortex, compared with other experiences and evaluated for an appropriate response (Streeck-Fischer & van der Kolk, 2000).
When children feel they are being threatened, the fast tracts of the limbic system are likely be to activated before the slower prefrontal cortex has a chance to evaluate the stimulus (Streeck-Fischer & van der Kolk, 2000). Only a state of non hyper-arousal allows the activation of the prefrontal cortex needed for learning and problem solving.
- Increased limbic system sensitivity
The limbic system is a network of brain cells sometimes called ‘the emotional brain’. It controls many of the most fundamental emotions and drives pertinent for survival (McLean Hospital, 2000). The limbic system is the area in the brain that initiates the fight, flight or freeze responses in the face of threat. The amygdala and the hippocampus are part of the limbic system. A study by Teicher et al. (1993) found a 38% increased rate of limbic abnormalities (‘emotional brain’) following physical abuse, 49% after sexual abuse, and 113% following abuse of more than one type combined (cited in Streeck-Fischer & van der Kolk, 2000).
The amygdala processes emotions before the cortex gets the message that something has happened. For example, the sound of a loved one’s voice is communicated to the amygdala, and the amygdala generates an emotional response to that information (for example, pleasure) by releasing hormones. When someone is threatened, the amygdala perceives danger and sets in motion a series of hormone releases that lead to the defensive responses of fight, flight or freeze. As the amygdala is immune to the effects of stress hormones it may continue to sound an alarm inappropriately, as is the core of post traumatic stress disorder (PTSD) (Rothschild, 2004).
The amygdala’s role in the encoding, storage and retrieval of emotionally-arousing material (and corresponding hormonal changes) primes animals to remember emotionally-charged or threatening events better than everyday events (Howe, Cicchetti and Toth, 2006).
- Decreased hippocampal volume
The hippocampus helps to process information and lends time and spatial context to memories and events. The hippocampus assists the transfer of initial information to the cortex which works to make sense of the information. However the hippocampus is vulnerable to stress hormones, in particular the hormones released by the amygdala’s alarm. When these hormones reach a high level, they suppress the activity of the hippocampus and it loses its ability to function. Information that would make it possible to differentiate between a real and an imagined threat never reaches the cortex and a rational evaluation of the information isn’t possible (Rothschild, 2004).
If a particular stimulus is misinterpreted as a threat, this leads to immediate fight/flight/freeze responses (to non-threatening stimuli). This causes this system to respond to minor irritations in a totalistic manner (Streeck-Fischer & van der Kolk, 2000).
Research shows that environments of extreme stress lead to increased cortisol levels (Murray-Close, Han, Cicchetti, Crick, & Rogosch, 2008) which can lead to decreased hippocampal volume. Decreased hippocampal volume has been associated with poorer declarative memory which places adults at greater risk of developing PTSD-like symptoms, and is closely correlated with experiences of depression and physical inflammations (Danese, Pariante, Caspi, Taylor & Poulton, 2006).
- Underdevelopment of left brain
A study by McLean Hospital (2000) found that children with histories of abuse were twice as likely as non-abused children to have abnormal EEGs. Research shows evidence of deficient development of the left brain hemisphere in abused patients (which controls language), suggesting that the right hemisphere may be more active than in healthy individuals (McLean Hospital, 2000).
- A smaller corpus callosum
The corpus callosum is a major information pathway connecting the two hemispheres of the brain (McLean Hospital, 2000). A number of studies have found that the corpus callosum is smaller in abused children than in healthy children (De Bellis et al., 1999; McLean Hospital, 2000; Teicher, Ito, Glod, & Andersen, 1997). Furthermore, McLean Hospital (2000) found that abused patients shifted the degree of activity between the two hemispheres to a much greater extent than normal. They theorised that a smaller corpus callosum leads to less integration of the hemispheres. This can lead to dramatic shifts in mood or personality.
- Neuro-endocrine alterations
Brain development is affected by stress early in development. Extensive research has been carried about the neuro-biology of stress. The link between a history of childhood abuse and neglect and neuro-endocrine impacts is well established. Research tells us that the bodies of children who are being abused react and adapt to the unpredictable dangerous environments to which they are exposed. Stress can set off a ripple of hormonal changes that permanently wire a child’s brain to cope with a malevolent world (Teicher, 2002). Through this chain of events, violence and abuse pass from generation to generation (Teicher, 2002).
The neuro-endocrine system refers to the system of interaction between our brain/ nervous system and the hormones in our bodies. This system helps regulate our moods, our stress response, our immune system, and our digestion, among other things. Any disruption to the neuro-endocrine system affects a range of basic psychological and physiological functions.
Research suggests that many of the long-term impacts of child abuse experienced by adult survivors result from the chronic neuro-endocrine dysregulation caused by prolonged exposure to abuse and violence (Kendall-Tackett, 2001). Activity of the hypothalamic-pituitary-adrenocortical (HPA) axis has been identified as mediating the effects of adversity on the developing brain. The HPA axis consists of the hypothalamus and the pituitary gland in the brain and the adrenal glands at the top of the kidneys. The HPA Axis is a major part of the neuroendocrine system that controls reactions to stress and regulates body processes, including digestion, the immune system, mood and emotions, sexuality, and energy storage and expenditure.
- Impact on stress hormones (including impact on cortisol production)
Even in utero foetuses experience stress (Cozolino, 2002). Tests have found that foetuses express a biological response indicative of a stress response well before birth (Gunnar, 1998). The two hormones that are associated with increased arousal (as found in animal studies) are cortisol and adrenocorticotropic hormone.
The nervous systems of children who are abused run on a constant high because they are constantly anticipating further danger. Their bodies are flooded with fight-or-flight hormones (Cozolino, 2002). A study by Linares et al. (2008) shows a neuro-endocrine alteration in cortisol production in children with histories of abuse and neglect. This state of chronic “hyper-arousal” persists for many survivors throughout their adult years as well. Even when the abuse and violence have ceased and the environment is ‘safe’, many adult trauma survivors still perceive the threat to be present; their fear is maintained and becomes pathological (Giarratano, 2004b). A study by Joyce et al. (2007) found that experiences of childhood abuse were associated with high cortisol levels in depressed adult survivors.
A number of studies have identified alterations in cortisol production in both children and adults who experienced childhood abuse (Carpenter et al., 2007; Joyce et al., 2007; Linares et al., 2008; McLean Hospital, 2000). Alteration in cortisol levels, either an increase or decrease, can cause a number of long-term physical and psychological health concerns.
- Impact on thyroid production
Studies conducted by McLean Hospital (2000) have found that neglect can also decrease production of thyroid hormone. This can lead to a number of health concerns as the thyroid gland secretes hormones which modulate metabolism.
Trauma is biologically encoded in the brain in a variety of ways. Changes in structures like the hippocampus, and the coordination and integration of neural network functioning have been identified. These changes are reflected in the victim’s physiological, psychological and interpersonal experiences (Cozolino, 2002). Deficits in psychological and interpersonal functioning then create additional stress which further compromise neurobiological structures. In this way, adaptation to trauma, especially early in life, becomes a “state of mind, brain, and body” around which subsequent experience organises (Cozolino, 2002).