The challenge of mapping diagnostic categories onto developmental pathophysiology: DSM-6 anyone?

Behavioural and emotional concerns reported by parents of children attending a neurodevelopmental diagnostic centre

BACKGROUND

Behavioural and emotional problems are a salient concern for parents of children with neurodisability, but little is known about the nature of such concerns in this population, nor about the distribution of concern types across ostensibly different subpopulations.

METHODS

Information about behavioural and emotional concerns was extracted from clinical reports of developmental paediatricians (N = 12) who had assessed children aged 3 to 8 years (N = 129) through three clinics at a major developmental and rehabilitation service centre. All concerns were captured at a granular level. A two-stage, consensus-based interdisciplinary concept-sorting technique was used to identify and group thematically related behavioural and emotional concerns into First Stage Groupings, intended to preserve detail and specificity, and a reduced number of Second Stage Clusters.

RESULTS

A total of 669 discrete concerns were encountered, aggregated to 58 First Stage Concern Groupings and 28 Second Stage Concern Clusters. Findings of the salience of Groupings related to Attention, Concentration and Distractibility, and Anxiousness, Shyness, and Emotional Sensitivity reflect existing literature for children with neurodevelopmental concerns. "Social Isolation/Peer Engagement," "Tantrums/Outbursts/Meltdowns" and "Volatility/Self-regulation Difficulties," and "Sensory Issues" emerged as areas of significant concern and salience as well. Across clinics, three Clusters recurred among the top five observed for each clinic: "Tantrums/Outbursts/Meltdowns," "Inflexibility/Gets Stuck or Fixated," and "Social Behaviours."

CONCLUSIONS

This rich descriptive dataset affords insight into the phenomenology of behaviour and emotional concerns in the daily lives of parents whose children have known or suspected neurodisability. Study findings can inform and sensitize clinicians working with this population. Usefulness is enhanced by inclusion of behavioural material that is subthreshold for a formal psychopathologic diagnosis. Certain concern types are encountered commonly across different clinical subpopulations, supporting a noncategorical view of behavioural and emotional problems as functional attributes that cross neurodisability diagnostic categories.

Elevated morning cortisol is a stratified population-level biomarker for major depression in boys only with high depressive symptoms

Major depressive disorder (MD) is a debilitating public mental health problem with severe societal and personal costs attached. Around one in six people will suffer from this complex disorder at some point in their lives, which has shown considerable etiological and clinical heterogeneity. Overall there remain no validated biomarkers in the youth population at large that can aid the detection of at-risk groups for depression in general and for boys and young men in particular. Using repeated measurements of two well-known correlates of MD (self-reported current depressive symptoms and early-morning cortisol), we undertook a population-based investigation to ascertain subtypes of adolescents that represent separate longitudinal phenotypes. Subsequently, we tested for differential risks for MD and other mental illnesses and cognitive differences between subtypes. Through the use of latent class analysis, we revealed a high-risk subtype (17% of the sample) demarcated by both high depressive symptoms and elevated cortisol levels. Membership of this class of individuals was associated with increased levels of impaired autobiographical memory recall in both sexes and the greatest likelihood of experiencing MD in boys only. These previously unidentified findings demonstrate at the population level a class of adolescents with a common physiological biomarker specifically for MD in boys and for a mnemonic vulnerability in both sexes. We suggest that the biobehavioral combination of high depressive symptoms and elevated morning cortisol is particularly hazardous for adolescent boys.

General distress, hopelessness-suicidal ideation and worrying in adolescence: concurrent and predictive validity of a symptom-level bifactor model for clinical diagnoses

BACKGROUND

Clinical disorders often share common symptoms and aetiological factors. Bifactor models acknowledge the role of an underlying general distress component and more specific sub-domains of psychopathology which specify the unique components of disorders over and above a general factor.

METHODS

A bifactor model jointly calibrated data on subjective distress from The Mood and Feelings Questionnaire and the Revised Children's Manifest Anxiety Scale. The bifactor model encompassed a general distress factor, and specific factors for (a) hopelessness-suicidal ideation, (b) generalised worrying and (c) restlessness-fatigue at age 14 which were related to lifetime clinical diagnoses established by interviews at ages 14 (concurrent validity) and current diagnoses at 17 years (predictive validity) in a British population sample of 1159 adolescents.

RESULTS

Diagnostic interviews confirmed the validity of a symptom-level bifactor model. The underlying general distress factor was a powerful but non-specific predictor of affective, anxiety and behaviour disorders. The specific factors for hopelessness-suicidal ideation and generalised worrying contributed to predictive specificity. Hopelessness-suicidal ideation predicted concurrent and future affective disorder; generalised worrying predicted concurrent and future anxiety, specifically concurrent generalised anxiety disorders. Generalised worrying was negatively associated with behaviour disorders.

LIMITATIONS

The analyses of gender differences and the prediction of specific disorders was limited due to a low frequency of disorders other than depression.

CONCLUSIONS

The bifactor model was able to differentiate concurrent and predict future clinical diagnoses. This can inform the development of targeted as well as non-specific interventions for prevention and treatment of different disorders.