Table 1.

Summary of the measures used in the study.

Measures collected at clinical psychological medicine assessment
RAHC- GAF	The Royal Alexandra Hospital for Children Global Assessment of Function (RAHC-GAF) is the DSM-IV-TR GAF modified to include functional impairment secondary to physical illness (AmericanPsychiatric, 2000). The scale has 100 points and 10 categories (10 points each). Healthy controls fall into the upper two brackets “superior in all areas (score 91–100) or “good in all areas (score 81–90). Lower values (and brackets) mark functional impairment of increasing severity. Patients with physical or psychological impairment fall into the lower brackets (score < 81).
Assessments of attachment using the Dynamic Maturational Method	Attachment interviews are age-appropriate structured clinical interviews about childhood experiences that are audiotaped, transcribed, and linguistically analyzed by a blinded coder using the Dynamic Maturational Model of Attachment discourse analysis (Farnfield et al., 2010, Crittenden et al., 2010, Kozlowska et al., 2011). The patterns of attachment fall into 2 clusters: a normative cluster (types A1–2, B1–5, C1–2) and an ‘at-risk’ cluster (Types A + (A3–6), Types C + (C3–6) and mixed A +/C +). Normative patterns of attachment are found in healthy children and adolescents and at-risk patterns of attachment are found in children and adolescents presenting to mental health services (Crittenden et al., 2010, Kozlowska et al., 2011, Kozlowska and Elliott, 2017, Ratnamohan and Kozlowska, 2017). The coder also identifies discourse markers of unresolved loss or trauma—dangerous or distressing past events that the speaker struggles to integrate into the narrative in a coherent way. Unresolved loss or trauma can pertain to relational stressors, adverse life events or exposure to domestic violence or physical, emotional or sexual abuse.
Measures collected via the web-based assessment
Spot-the-word Test (IQ estimate)	The spot-the-word test is an IQ estimate. Subjects are presented with pairs of items comprising one word and one non-word, and requiring the subject to identify the word (Baddeley et al., 1993, Hatch et al., 2010). Performance correlates highly with verbal intelligence and in adult's correlates with performance on the National Adult Reading Test (NART).
SPHERE-12	The Somatic and Psychological Health Report (SPHERE) is a self-rating screening tool for common mental health disorders in primary care (Hickie et al., 2001). The SPHERE has six psychological items (PSYCH-6) and six somatic/fatigue items (SOMA-6) rated in terms of how troubling they were over the past few weeks. Respondents are considered to have a possible psychological disorder if they have a score of 2 or more on the PSYCH-6 scale, and a score of 3 or more on the SOMA-6 scale.
DASS-21	The Depression Anxiety and Stress Scales are in paediatric populations is a validated measure of perceived distress in paediatric populations (Lovibond and Lovibond, 1995, Patrick et al., 2010).
WHOQOL	The World Health Organization Quality of Life (1995) scale provides information—a score out of a 100—about physical health, psychological health, social health and environmental health. High scores reflects high quality of health and low scores reflects low quality of health
ELSQ	The early life stress questionnaire (ELSQ) is a checklist of 19 stress items—and an option for elaboration—based on the Child Abuse and Trauma Scale (Cohen et al., 2006). Twelve items pertained to relational stressors including: bullying; physical abuse; sexual abuse; emotional abuse; neglect; parental separation; loss by separation; loss by death; family conflict; severe illness of a family member; domestic violence and other. Other items pertain to birth complications, life threatening/severe illness, war trauma, and natural disasters. Participants record if they have or have not experienced the given stressor and the age period during which the stressor has been experienced.
Measures collected in the laboratory
Emotion-identification task	The emotion-identification task involves presentation of 48 facial expressions of emotion—happiness, fear, anger, sadness, disgust, and neutral—for 2 s on a black background on a touchscreen (Gur et al., 2002, Palmer, 2009, Williams et al., 2009). Participants identify each expression by selecting the verbal label corresponding to the emotion in each expression from one of six options. Speed and accuracy of responding are equally stressed in the task instructions. Primary dependent measures are accuracy and reaction time for correct identification. This task has been normed for children from 6 to 18 years of age, as well as for adults 18 to 79 years of age (Palmer, 2009, Williams et al., 2009).