Comorbidity Between Internalising and Externalising Disorders Among Adolescents: Symptom Connectivity Features and Psychosocial Outcome

Internalising disorders are highly prevalent conditions in adolescence and tend to co-occur with externalising disorders. The present study used a symptom network approach to examine the interplay between symptoms of internalising disorders among adolescents with comorbid internalising and externalising disorders. Data comes from the National Comorbidity Survey—Adolescent Supplement, a nationally representative survey of adolescents aged 13 to 18 years. The most central symptoms across the disorders in the network were poor self-esteem and worry. The comorbidity between anxiety and depression increases the probability of having comorbid externalising disorders. Adolescents with both internalising and externalising disorders had the highest rate of health service utilisation. Comorbidity group, lifestyle factors, deficits in cognitive and academic competence and coping skills were significant covariates of the mental health outcomes. Understanding comorbidity profile of internalising and externalising disorders and central symptoms that bridge these disorders could have important clinical implications.

Mindfulness-based intervention and aggression and rule-breaking behaviours in elementary school boys: a proof of concept trial

This study investigated the effect of a mindfulness-based intervention on pathological symptoms in boys with externalised disorders. A total of 24 elementary school students with externalising disorders, diagnosed by completing the Child Behavior Checklist (CBCL), were randomly assigned to a mindfulness-based intervention for two months. One session per week was offered and each session lasted one hour (n = 12) or as a wait-list control group (n = 12). Data were analysed via a multivariate analysis of covariance (MANCOVA) test. Students from the intervention group showed greater reductions in rule-breaking behaviours than those in the wait-list control group. Also, there was clear superiority of the intervention relative to the wait-list control group for reducing both aggression and rule-breaking behaviours (effect size differences were d = −2.52 and d = −1.88 respectively). These positive results on outcome measures provide initial evidence for a mindfulness-based intervention as a treatment option for boys with externalising disorders.

Prenatal smoking, alcohol and caffeine exposure and offspring externalising disorders: A systematic review and meta-analysis

Background and aims: Several studies have indicated that there is an association between maternal prenatal substance use and offspring externalising disorders. However, it is uncertain whether this relationship is causal. Therefore, we updated a previously conducted systematic review to determine if the literature supports 1) a causal role of maternal prenatal substance use on offspring externalising disorders and 2) whether these associations differ across externalising disorders. Methods: We searched Web of Science, Embase, PsycINFO and Medline databases. We included studies that examined smoking, alcohol or caffeine use during pregnancy as an exposure, and diagnosis of attention-deficit hyperactivity disorder (ADHD), conduct disorder (CD) and oppositional-defiant disorder (ODD) in offspring as an outcome. Studies on non-English language, fetal alcohol syndrome and comorbid autism spectrum disorders were excluded. Risk of bias assessment was conducted using Newcastle Ottawa Scale (NOS) and where possible meta-analysis was conducted for studies classed as low risk of bias. Results: We included 63 studies. All studies were narratively synthesised, and 7 studies were meta-analysed on smoking and ADHD. The majority of studies (46 studies) investigated the association between smoking and ADHD. Studies which accounted for genetic effects indicate that the association between smoking and ADHD is unlikely to be causal. Studies on alcohol exposure in all the outcomes reported inconsistent findings and no strong conclusions on causality can be made. Studies on caffeine exposure were mostly limited to ADHD and these studies do not support a causal effect. Conclusions: There is no causal relationship between maternal smoking during pregnancy and attention-deficit hyperactivity (ADHD) in offspring. However, given that the majority of identified studies investigated the association between ADHD and smoking exposure, findings with alcohol and caffeine exposures and conduct disorder (CD) and oppositional-defiant disorder (ODD) need more research, especially using more genetically sensitive designs.

Association of genetic liability to smoking initiation with e-cigarette use in young adults: A cohort study

Background Tobacco smoking and e-cigarette use are strongly associated, but it is currently unclear whether this association is causal, or due to shared factors that influence both behaviours such as a shared genetic liability. The aim of this study was to investigate whether polygenic risk scores (PRS) for smoking initiation are associated with ever use of e-cigarettes. Methods and findings Smoking initiation PRS were calculated for young adults (N = 7,859, mean age = 24 years, 51% male) of European ancestry in the Avon Longitudinal Study of Parents and Children, a prospective birth cohort study initiated in 1991. PRS were calculated using the GWAS & Sequencing Consortium of Alcohol and Nicotine use (GSCAN) summary statistics. Five thresholds ranging from 5 × 10−8 to 0.5 were used to calculate 5 PRS for each individual. Using logistic regression, we investigated the association between smoking initiation PRS and the main outcome, self-reported e-cigarette use (n = 2,894, measured between 2016 and 2017), as well as self-reported smoking initiation and 8 negative control outcomes (socioeconomic position at birth, externalising disorders in childhood, and risk-taking in young adulthood). A total of 878 young adults (30%) had ever used e-cigarettes at 24 years, and 150 (5%) were regular e-cigarette users at 24 years. We observed positive associations of similar magnitude between smoking initiation PRS (created using the p < 5 × 10−8 threshold) and both smoking initiation (odds ratio (OR) = 1.29, 95% CI 1.19 to 1.39, p < 0.001) and ever e-cigarette use (OR = 1.24, 95% CI 1.14 to 1.34, p < 0.001) by the age of 24 years, indicating that a genetic predisposition to smoking initiation is associated with an increased risk of using e-cigarettes. At lower p-value thresholds, we observed an association between smoking initiation PRS and ever e-cigarette use among never smokers. We also found evidence of associations between smoking initiation PRS and some negative control outcomes, particularly when less stringent p-value thresholds were used to create the PRS, but also at the strictest threshold (e.g., gambling, number of sexual partners, conduct disorder at 7 years, and parental socioeconomic position at birth). However, this study is limited by the relatively small sample size and potential for collider bias. Conclusions Our results indicate that there may be a shared genetic aetiology between smoking and e-cigarette use, and also with socioeconomic position, externalising disorders in childhood, and risky behaviour more generally. This indicates that there may be a common genetic vulnerability to both smoking and e-cigarette use, which may reflect a broad risk-taking phenotype.

Previous disorders and depression outcomes in individuals with 12-month major depressive disorder in the World Mental Health surveys

Aims Major depressive disorder (MDD) is characterised by a recurrent course and high comorbidity rates. A lifespan perspective may therefore provide important information regarding health outcomes. The aim of the present study is to examine mental disorders that preceded 12-month MDD diagnosis and the impact of these disorders on depression outcomes. Methods Data came from 29 cross-sectional community epidemiological surveys of adults in 27 countries (n = 80 190). The Composite International Diagnostic Interview (CIDI) was used to assess 12-month MDD and lifetime DSM-IV disorders with onset prior to the respondent's age at interview. Disorders were grouped into depressive distress disorders, non-depressive distress disorders, fear disorders and externalising disorders. Depression outcomes included 12-month suicidality, days out of role and impairment in role functioning. Results Among respondents with 12-month MDD, 94.9% (s.e. = 0.4) had at least one prior disorder (including previous MDD), and 64.6% (s.e. = 0.9) had at least one prior, non-MDD disorder. Previous non-depressive distress, fear and externalising disorders, but not depressive distress disorders, predicted higher impairment (OR = 1.4–1.6) and suicidality (OR = 1.5–2.5), after adjustment for sociodemographic variables. Further adjustment for MDD characteristics weakened, but did not eliminate, these associations. Associations were largely driven by current comorbidities, but both remitted and current externalising disorders predicted suicidality among respondents with 12-month MDD. Conclusions These results illustrate the importance of careful psychiatric history taking regarding current anxiety disorders and lifetime externalising disorders in individuals with MDD.

Adolescent psychiatric outpatients and their caregivers: Comparing the Strengths and Difficulties Questionnaire

Background: The use of the SDQs as a screening tool to monitor new or ongoing problems in adolescent psychiatric outpatients is needed to improve clinical outcomes. Discrepancies between parent and adolescent reports on the Strengths and Difficulties Questionnaire (SDQ), reflects the degree of emotional and behavioural symptoms. This may affect their ability to work together to reach therapeutic goals.Aim: The level of SDQ (dis)agreements between adolescent-parental self-reports in adolescent psychiatric outpatients was examined.Setting: Weskoppies Child and Adolescent outpatients.Methods: This two-group cross-sectional comparative study obtained SDQ responses from 74 psychiatrically diagnosed adolescents and their parents (148 completed SDQ questionnaires). Adolescent outpatients aged between 11 and 18 years following up at the outpatients between July 2017 and November 2017 were included. Adolescent and parent rating scores were compared using a paired sample t-test, and patterns of agreement were measured by using Pearson’s correlation coefficient and Cohen’s kappa.Results: Parents reported more difficulties than adolescents, although differences were non-significant (p 0.58). Caregivers and adolescents agreed on the conduct domain and on emotional symptoms (0.21 ≤ kappa ≤ 0.40, p 0.05). Caregivers and adolescents agreed on the presentation of internalising and externalising disorders (R = 0.48, p 0.001).Conclusions: The SDQ confirmed fair agreement between parents and adolescents. Parental perceptions of adolescent behavioural difficulties could influence parent– adolescent relations and communication. Using the SDQ as a screening tool in South Africa, requires further validation for it to be integrated as part of a multi-informant best-practice approach.

Association of genetic liability to smoking initiation with e-cigarette use in young adults

BackgroundSmoking and e-cigarette use are strongly associated, but it is currently unclear whether this association is causal, or due to shared factors that influence both behaviours such as a shared genetic liability. The aim of this study was to investigate whether polygenic risk scores (PRS) for smoking initiation are associated with ever use of e-cigarettes.Methods and FindingsPRS of smoking initiation were calculated for young adults (aged 23 to 26 years) of European ancestry in the Avon Longitudinal Study of Parents and Children using the GWAS & Sequencing Consortium of Alcohol and Nicotine use (GSCAN) summary statistics. Five thresholds ranging from 5×10−8 to 0.5 were used to calculate five PRS for each individual. Using logistic regression, we investigated the association between smoking initiation PRS and both self-reported smoking initiation and self-reported e-cigarette use, as well as a number of negative control outcomes (socioeconomic position at birth, externalising disorders in childhood and risk-taking in young adulthood). We observed positive associations of similar magnitude between smoking initiation PRS and both smoking initiation (OR = 1.29, 95% CI 1.19 to 1.39) and ever e-cigarette use (OR = 1.24, 95% CI 1.14 to 1.34) by the age of 24 years. At lower p-value thresholds, we observed an association between smoking initiation PRS and ever e-cigarette use among never smokers. We also found evidence of associations between smoking initiation PRS and some negative control outcomes, particularly when less stringent p-value thresholds were used but also at the strictest threshold (e.g., gambling, number of sexual partners, conduct disorder at 7 years, and parental socioeconomic position at birth).ConclusionsOur results indicate that there may be a shared genetic aetiology between smoking and e-cigarette use, and also with socioeconomic position, externalising disorders in childhood, and risky behaviour more generally. Taken together, this indicates that there may be a common genetic vulnerability to both smoking and e-cigarette use, which may reflect a broad risk-taking phenotype.

Considerations related to vaping as a possible gateway into cigarette smoking: an analytical review

Background: Compared to cigarette smoking, e-cigarette use is likely to present a reduced risk of smoking-related disease (SRD). However, several studies have shown that vaping predicts smoking initiation and might provide a gateway into smoking for those who otherwise would never have smoked. This paper considers various aspects of the gateway issue in youths. Methods: Here, we reviewed studies (N=15) of the gateway effect examining how extensively they accounted for confounders associated with smoking initiation in youths. We estimated how omitting a confounder, or misclassifying it, might bias the association between vaping and smoking initiation. We assessed how smoking prevalence might be affected by any true gateway effect, and examined trends in youth smoking and e-cigarette use from national surveys. Results: The list of smoking predictors adjusted for in studies reporting a significant gateway effect is not comprehensive, rarely considering internalising/externalising disorders, outcome expectancies, school performance, anxiety, parental smoking and peer attitudes. Furthermore, no study adjusted for residual confounding from inaccurately measured predictors. Better adjustment may substantially reduce the estimated gateway effect. Calculations showed that as any true gateway effects increase, there are much smaller increases in smoking prevalence, and that gateway effects increase only if initiating vaping is more frequent than initiating smoking. These effects on prevalence also depend on the relative odds of quitting vs. initiation. Data from five surveys in US/UK youths all show that, regardless of sex and age, smoking prevalence in 2014–2016 declined faster than predicted by the preceding trend, suggesting the absence of a substantial gateway effect. We also present arguments suggesting that even with some true gateway effect, introducing e-cigarettes likely reduces SRD risk. Conclusions: A true gateway effect in youths has not yet been demonstrated. Even if it were, e-cigarette introduction may well have had a beneficial population health impact.

Does behavioural inhibition system dysfunction contribute to Attention Deficit Hyperactivity Disorder?

The Reinforcement Sensitivity Theory of Personality has as its main foundation a Behavioural Inhibition System (BIS), defined by anxiolytic drugs, in which high trait sensitivity should lead to internalising, anxiety, disorders. Conversely, it has been suggested that low BIS sensitivity would be a characteristic of externalising disorders. BIS output should lead to increased arousal and attention as well as behavioural inhibition. Here, therefore, we tested whether an externalising disorder, Attention Deficit Hyperactivity Disorder (ADHD), involves low BIS sensitivity. Goal-Conflict-Specific Rhythmicity (GCSR) in an auditory Stop Signal Task is a right frontal EEG biomarker of BIS function. We assessed children diagnosed with ADHD-I (inattentive) or ADHD-C (combined) and healthy control groups for GCSR in: a) an initial smaller study in Dunedin, New Zealand (population ~120,000: 15 control, 10 ADHD-I, 10 ADHD-C); and b) a main larger one in Tehran, Iran (population ~9 [city]-16 [metropolis] million: 27 control, 18 ADHD-I, 21 ADHD-C). GCSR was clear in controls (particularly at 6–7 Hz) and in ADHD-C (particularly at 8–9 Hz) but was reduced in ADHD-I. Reduced attention and arousal in ADHD-I could be due, in part, to BIS dysfunction. However, hyperactivity and impulsivity in ADHD-C are unlikely to reflect reduced BIS activity. Increased GCSR frequency in ADHD-C may be due to increased input to the BIS. BIS dysfunction may contribute to some aspects of ADHD (and potentially other externalising disorders) and to some differences between the ADHD subtypes but other prefrontal systems (and, e.g. dopamine) are also important.