One of the things I am committed to in my PhD, is to write a short version of my articles for people with the curiosity to engage with research but who may not have the time or practice of reading long-form academic articles. This is also for my family and friends who want to read my articles but understandably balk at the 50 pages. So here is my attempt to describe the first study of my PhD in an accessible format.

What was the background to this study?

There is a lot of evidence that childhood adversity is an important causal factor in mental health problems in later life. You may have heard of people talking about childhood trauma that they have experienced. Here, I and my colleagues focused on adversities such as being abused, being neglected, having a caregiver with a substance use problem, being bullied and experiencing other such interpersonal adversities, usually at home, school or in the community. But it is not fully known how or why someone who has experienced adversity in their childhood goes on to experience more depression and anxiety. While the answer to this question may seem obvious and intuitive in some ways, there are a lot of unknowns about how adversity affects the brain and its functioning – how it affects the way one thinks, feels and behaves. Another way of thinking about this is the “pathways” or the “mechanisms” through which adversity impacts mental health. Finding this out can help in designing better and evidence-based interventions for people who have experienced adversity.

What did we aim to do?

Based on our intuition and existing literature, we identified four ways of thinking/feeling/behaving that we thought could be affected by experiencing adversity and that could, in turn, affect our social relationships and mental health:

• Trust: how willing we are to be vulnerable with other people and expect that they will respond positively

• Mentalizing: how well we understand our and other people’s mental states – desires, intentions, emotions

• Agency: the extent to which we feel in control of our lives and feel we can change things

• Interpersonal emotion regulation: the extent to which we reach out to others to help manage our emotions and how much we feel helped by other people

We aimed to conduct a scoping review on whether childhood adversity is linked to these four ways of thinking/feeling/behaving and whether these “mechanisms” are, in turn, linked to mental health outcomes such as having symptoms of depression, anxiety, psychosis and so on. A systematic/scoping review is a method of searching through scientific literature in a planned and unbiased manner to synthesize key findings.

I chose to do this rather than collecting any new data myself, because I knew that many studies on these concepts existed already and I felt it was important for someone to synthesize this existing evidence to understand what is already known, to avoid repetition and to identify what is a gap for the future.

What were the methods?

First, I preregistered the study which can be accessed here. Preregistration is a method to say publicly in advance what a researcher is going to do and how. This is helpful to prevent the researcher from changing things later and makes the review less biased (e.g., it prevents me from excluding studies I don’t like or only including studies from authors I know, because I have pre-specified how I will search and select studies).

Second, I searched key scientific databases using search terms such as abuse/neglect/adversity/maltreatment, trust/mentalize/agency/emotion regulation, and depression/anxiety/psychosis etc. This gave me 3825 “hits” i.e. all the scientific articles that included these terms.

Third, I and a colleague of mine screened these articles to identify the ones that met our inclusion criteria. We practised on a few articles and double-screened 10% of all articles, to make sure that we were making similar decisions of whether to include/exclude an article. Then I single-screened the rest of the articles.

Finally, after this process, we had whittled down the 3825 initial hits to 84 articles (comprised of 78 studies). Then I extracted the research questions, methods and key findings from these 84 articles which I have summarised in the tables available here: see supplemental material S4: S7.

What did we find?

1. We found a total of 15 studies on trust (written as 16 articles) that looked at adversity and mental health. These studies showed that experiencing adversity was generally linked to higher self-reported distrust, higher distrust of typically trustworthy faces, lesser differentiation between trustworthy and untrustworthy faces, a stronger brain response to trustworthy faces and a lower brain response to violations of trust. This suggests that people with trauma experience might be tuned towards distrust. Interestingly, some studies also found that adversity was also linked to higher credulity (that is, tendency to believe information given to us by others, without being very vigilant about it). Both distrust and credulity were, in turn, linked to more symptoms of depression, post-traumatic stress, anxiety, borderline personality disorder ¹ and conduct problems.

2. We found a total of 37 studies on mentalizing (written as 41 articles) that looked at adversity and mental health. These studies showed that experiencing adversity was generally linked to feeling more uncertain about one’s own mental states, such as not understanding one’s own emotions, desires and intentions. Adversity was not linked to feeling excessive certainty about mental states or to feeling uncertain about other people’s mental states. Feeling more uncertain about one’s own mental states was, in turn, linked to more depressive symptoms, self-harm, suicidality, dissociative symptoms, PTSD symptoms, anxiety symptoms, eating disorder symptoms and other mental health symptoms.

3. We found a total of 26 studies on agency (written as 27 articles) that looked at adversity and mental health. These studies showed that experiencing adversity was generally linked to a higher external locus of control (that is, feeling that one’s life was controlled more by luck, chance or powerful others), which was in turn linked to more symptoms of depression, psychosis, anxiety and suicidal ideation. However, some studies found that adversity was not linked to sense of control, but a high internal locus of control acted as a protective factor and was linked to better mental health regardless.

4. We found only 3 studies on interpersonal emotion regulation (written as 3 articles) that looked at adversity and mental health. Hence, we concluded that this area of research was scarce and more studies were needed to draw any reliable conclusions.

What does this all mean?

Across 78 studies, we identified that individuals who have experienced childhood adversity may mistrust others, feel more uncertain about and be less accurate in identifying intentional mental states and perceive more external control over their lives, which in turn is linked to mental health symptoms across all sorts of diagnostic categories that are traditionally identified in psychiatry. We found less studies on interpersonal emotion regulation – this doesn’t mean that it’s not important, but that it hasn’t been researched a lot yet.

Clinically, our findings suggest that when we are trying to help children or adults who have experienced adversity, focusing on how they trust others, their understanding of their mental states and how they experience control over their lives could be important areas to intervene with. I personally think this could also help us in designing trauma-informed systems, because one could consider, for example, that individuals who have experienced trauma may feel more distrust of others, but at the same time, also tend to feel they’re naïve and may believe information they are told more easily. What implications might this have for how schools, social care and healthcare services operate, which are often the first point of contact for many of these individuals?

Some of my (extremely) speculative ideas are as follows. First, services could attempt to communicate information more transparently, with language markers that encourage questions/clarification/critical perspectives to help reduce both distrust and credulity. Second, services could explicitly use ideas from mentalization-based treatments to help deal with the uncertainty that service users may be feeling when they interact with teachers, doctors and other staff (for example, promoting a curious stance in staff). Third, services could identify whether there are points of contact that might inadvertently be reinforcing an external sense of control, for example, appointment or waitlist procedures that do not provide any choice.

However, we also identified methodological limitations in the evidence we found:

1. A majority of the evidence was cross-sectional and used statistical models that make a lot of assumptions. What this means is that we can’t be sure whether adversity actually causes changes in these four ways of thinking/feeling/behaving. A lot of other factors could be “confounding” this association, for example, preexisting mental health problems or poverty. And if it is indeed true that other factors are the true causes, then it would make more sense to focus on those factors instead of focusing on adversity.

2. We also found that there was a lot of inconsistency in how concepts like trust, mentalizing and agency were measured. Not everybody used the same measures or even the same definitions of trust or mentalizing, which meant that it was difficult to separate out issues of measurement from true findings (what if a study didn’t find an effect because of how they measured trust rather than there actually being no effect on trust? What if a study was actually measuring something else, like emotion regulation, when they purported to measure mentalizing?).

3. We also recommended that reporting in future scientific articles should be more rigorous and transparent, because, for example, some articles did not mention that they used the same sample as used in other studies or did not report the full effect sizes. Other articles had minor errors or typos which I reached out to authors to clarify.

Summary

Overall, this review was motivated by the idea that human beings don’t exist in isolation from our social world. When we experience trauma in childhood, it affects how we build and maintain our relationships during key periods of our life, such as adolescence. Many people who have experienced trauma feel less supported and experience a lower quantity and quality of social relationships. But what could underlie these changes?

We thought it could be things like trust, mentalizing, how in control we feel of our lives and how we seek out others to manage our emotions. Our formal review showed that there is some evidence for some of these constructs. Based on our findings, we suggested some ideas for future research and practice.

You can read the full article at the link below:

Citation

Acknowledgement: Thank you to Niranjanraj Ramasundaram for providing comments on and editing an earlier version of this article.