When bad experiences trigger anxiety: childhood trauma and PTSD

Traumas are events that involve danger of death, serious injury or sexual assault. After experiencing trauma, it’s not unusual for children to develop emotional and behavioural symptoms: they might become tearful, upset or clingy; struggle to pay attention or to sleep; or even get headaches and tummy aches. This is a normal psychological response and not a psychiatric disorder. However, by age 18, around one in four children exposed to trauma will have developed PTSD. This means they will begin to experience very severe, impairing or persistent symptoms, such as re-living the trauma, developing avoidance strategies, and experiencing physiological hyper-arousal.

Because not all children who experience trauma develop PTSD, it is important to understand how to identify the more vulnerable children in order to provide adequate support and treatment. Through my work in the Stress & Development Lab at King’s College London’s Institute of Psychiatry, Psychology & Neuroscience (IoPPN), my team and I aim to understand how traumatic experiences in childhood affect mental and physical health, how to identify those children at greatest risk of developing PTSD, and how to support children who have experienced trauma.

How traumatic experiences in childhood affect health

In PTSD, abnormal processing of traumatic memories leads to persistent re-experiencing of the event through unwanted and distressing memories or nightmares, particularly when there are triggers that resemble the context in which the traumatic event occurred.

Traumatic experiences require significant adaptations by the developing child. At a molecular level, the hormonal and immune systems are overactive to support facing or escaping from danger and recovering from injuries. At a neurobiological level, the brain becomes more aware of potential threats. At the psychological level, the traumatic experiences are encoded in autobiographical memories to minimise future threats. At the social level, the threats in the environment may lead to withdrawal and reduction in social connections.

Although these adaptations can be helpful to reduce threats, they may lead over time to maladaptive outcomes including mental health problems. For example, inflammation levels are higher in individuals who have experienced maltreatment compared to those who haven’t, and are associated with mental health problems later on.

In the Stress & Development Lab, we have conducted several detailed epidemiological studies based on large population-based birth cohorts to, firstly, investigate the impact of childhood trauma exposure on mental health outcomes, and secondly, identify which children are most at risk of developing PTSD.

Through analyses in the Environmental Risk (E-Risk) Longitudinal Twin Study (which observed twins born between 1994-95 until they were aged 18 years), in a paper led by Dr Stephanie Lewis, Clinical Lecturer at the IoPPN, we found that children with PTSD are eight times more likely to self-harm and 10 times more likely to attempt suicide than those without PTSD. In absolute terms, this means that about half of children with PTSD report self-harming and one in five report attempting suicide. Children with PTSD are also significantly more likely to have a violent offence record and not be in education, employment or training (NEET). This is alongside being at increased risk of co-occurring psychiatric diagnoses, including depression, generalised anxiety disorder, conduct problems, substance misuse or attention deficit and hyperactivity disorder (ADHD).

These findings highlight that childhood traumas are key modifiable risk factors for psychopathology in childhood and onwards – if we target the processes involved in responding to trauma, we may then be able to reduce the prevalence of mental health disorders and other negative health outcomes. As a result, childhood trauma is a major focus for research and clinical practice in mental health.

How to identify children most at risk of PTSD

We know that childhood trauma is associated with negative outcomes. But why are some children resilient in the face of trauma, while others develop complex psychopathologies like PTSD?

From our research, we have identified several key factors which influence the risk of developing PTSD in individual children exposed to trauma. Firstly, the quantity and nature of the trauma has an impact: children exposed to more traumatic events are at greater risk of developing persistent PTSD. In particular, those children who are exposed to ‘interpersonal traumas’ (such as physical or sexual assault) are more likely to develop PTSD than children exposed to ‘non-interpersonal traumas’ (such as accidents or natural disasters).

Secondly, individual differences in the child impact risk for PTSD: research suggests that girls are at greater risk of developing PTSD than boys following trauma. Different children also have different responses both during and after trauma: during the trauma, children who believed that they were about to die, and those who believe they are to blame for the occurrence of the traumatic event, may be at greater risk for developing PTSD. Children who try to cope with trauma by pushing memories away, withdrawing or distracting themselves may also be more likely to develop PTSD.

Interestingly, the memory of trauma also influences risk of developing mental health problems. Research has shown that individuals who were maltreated as children but do not have memories of these experiences have the same rates of mental health problems as individuals who were not maltreated individuals. This suggests that biases in memory, core beliefs, and decision-making influence risk for PTSD and other psychiatric responses to trauma.

Autobiographical memory may be a risk factor for trauma-related psychopathology. The subjective experience ('s') of child maltreatment (including memory) is more strongly associated with psychopathology than the objective experience ('o') measured through official court records. Graph from 'Objective and subjective experiences of child maltreatment and their relationships with psychopathology', Danese & Spatz Widom (2020).

Although these factors are more common in groups of children who develop PTSD than those who do not develop PTSD, much more research is still needed to make accurate risk prediction for individual children.

Dr Alan Meehan, Lecturer in Psychology at the IoPPN, and others in my team are working to develop accurate prediction models to identify which trauma-exposed children are at greatest risk of developing psychopathology. This will enable interventions from the earliest stages, even before symptoms occur, in children who have experienced trauma.

Identifying the symptoms of PTSD and what we can do to reduce them

Many children (around 50%) fail to recover from the symptoms of PTSD without treatment. Yet, despite the high prevalence of trauma in childhood, our research found that only a small fraction of children who have PTSD end up seeing a GP or mental health professionals. Around one in three sought help from a GP and only one in five, ultimately, were in contact with a mental health professional. This seems to be because children can struggle to report the symptoms or even the traumatic experiences themselves, and it’s difficult for parents and teachers to really understand when a child has developed PTSD.

As part of my work to reduce the negative impact of childhood trauma and PTSD, I co-lead the National & Specialist CAMHS Clinic for Trauma, Anxiety, and Depression at South London and Maudsley NHS Foundation Trust, where we deliver assessment and treatment to children and adolescents who experience severe and/or treatment-resistant PTSD, anxiety disorders and depression.

When we undertake assessments of PTSD in children who have been exposed to traumatic experiences, we look at a cluster of symptoms that are typical of developing PTSD. For example, asking:

• Does the child relive traumatic experiences through distressing memories or nightmares?
• Do they show avoidance of anything that reminds them of their trauma, such as context or people that reminds them of their trauma?
• Do they express feelings of guilt, isolation or detachment?
• Do they still feel under threat, as we can understand because they continue expressing irritability, impulsivity or difficulty concentrating, for example?

There are several evidence-based psychological treatments for PTSD in children that have been endorsed by the National Institute for Health and Care Excellence (NICE) and that we use in the CAMHS Clinic. These include trauma-focused psychotherapies which target cognitive and behavioural factors that contribute to the reinforcement of PTSD. These therapies generally include psychoeducation to provide information to children and families about PTSD symptoms and the treatment rationale, coping skills training to better manage intense negative emotions, gradual exposure to trauma memories and reminders to address avoidance and build a coherent trauma narrative, and cognitive restructuring to address biased appraisals related to the trauma memory. Consultant Clinical Psychologist and Reader, Dr Patrick Smith, and others at IoPPN have developed one form of this evidence-based treatment.

There is also limited but growing evidence to indicate that eye movement desensitisation and reprocessing (EMDR), which involves recalling traumatic events while performing tasks that generate bilateral sensory stimulation, may be beneficial for young people with PTSD.

Barriers to support and how to overcome them

We know it is impossible to implement interventions if child trauma and trauma-related psychopathology go undetected. As a result, our team is currently trying to map barriers to access healthcare to improve recognition of PTSD in children and adolescents.

One of the barriers to getting professional support for childhood PTSD are the symptoms and thought patterns themselves. Children may experience trauma-related avoidance, low motivation, hopelessness, distrust, shame, guilt, or fear of not being believed or being reprimanded by the perpetrators of the trauma. These factors may make them less likely to open up about the traumatic event or how they are feeling.

Another key barrier relates to the parents or caregivers’ response to their child’s trauma. For example, deliberate concealment of trauma by perpetrators or to avoid reprisal by perpetrators, fear of being blamed, fear of having their child taken by child protective services, or poor understanding and stigma around mental health. There may also be structural barriers, including lack of insurance, access to mental health care facilities or transportation.

Family can act as a great support system for children exposed to trauma. Children who received a family intervention which taught parents and caregivers about trauma symptoms, how to improve family communication, and coping skills to manage symptoms were significantly less likely to have a PTSD diagnosis three months after the intervention.

It is also important to remember that PTSD is not the only or even the most common mental health problem in children exposed to traumatic events, and parents and professionals need to also monitor symptoms of other anxiety disorders, depression and substance misuse in particular.

The future of mental health care and research: The King’s Maudsley Partnership for Children and Young People

Through his work in the Stress & Development Lab and National & Specialist CAMHS Clinic for Trauma, Anxiety, and Depression, Professor Andrea Danese is one of the many experts who are transforming our understanding and treatment of young people’s mental health as part of the King’s Maudsley Partnership for Children and Young People. The Partnership, which will have its home in the Pears Maudsley Centre for Children and Young People, is a unique collaboration between specialist clinicians from the South London and Maudsley NHS Foundation Trust and leading academics at King’s College London.

Together, King’s and The Trust host the largest group of mental health scientists and clinical academics in Europe. Through the Partnership, clinicians and researchers will collaborate even more closely to find new ways to predict, prevent and treat mental health disorders, such as childhood trauma and PTSD. This will enable us to translate research into practical treatments in the shortest possible time, and will benefit children locally, nationally and across the globe.