Childhood cognitive ability and its relationship with anxiety and depression in adolescence

Monozygotic twins discordant for depression: An extended network comparison of depressive symptoms, cognitive functions and daily activities

Monozygotic twins share the same genotype; however, they can be phenotypically discordant on various traits. Studying discordant monozygotic twins allows the investigation of differences in associations between symptoms and psychopathological risk factors, controlled for shared genetic liability. The network approach to psychopathology suggests that depressive symptoms, along with risk and protective factors (e.g., cognition, daily activities), form a complex system of mutually interacting components. We compared monozygotic twins discordant for lifetime depression on their respective extended networks of depressive symptoms, cognitive functions and daily activities (intellectual, physical, social), and evaluated if these networks differ in their associations between variables and in the role of each variable within the network. Regularized partial correlations investigated the networks' composition in 147 monozygotic twin pairs discordant for depression from the Danish Twin Registry. Affected twins had stronger overall associations within their network of depressive symptoms, cognitive functions and daily activities than their unaffected co-twins, while the importance of the network components' associations did not differ between the co-twins. In affected twins, decreased frequency in experiencing happiness had the strongest association with remaining variables (i.e., the most influence in activating other network elements). Also, variables from different groups were significantly associated (e.g., loneliness with delayed memory, pessimism with low social activities, verbal learning with intellectual activities). In unaffected twins, both mood symptoms and cognitive functions were important, but between-groups associations were quasi-absent. These results suggest that external events affecting the ability to feel happiness likely trigger the psychopathological process (depression network activation), independently from the genetic predisposition to depression.

Neurodevelopmental disorders in children seeking obesity treatment- associations with intellectual ability and psychiatric conditions

Background

Neurodevelopmental disorders (NDD), psychiatric comorbidity and cognitive deficits are commonly seen in children with obesity; however, little is known about the overlap between these conditions. This study aimed to examine the undiagnosed and diagnosed frequency of NDDs and explore its association with psychiatric conditions and general intellectual ability (IQ) in children presenting for obesity treatment.

Methods

In this observational study at two outpatient obesity clinics during 2018-2019, 80 children (8-17 years) were consecutively recruited, and screened for NDD unless already diagnosed with an NDD. A psychiatric unit evaluated children who screened positive for NDD. Diagnoses and clinical background factors were collected from medical records. IQ was assessed with the Weschler Intelligence Scales and internalizing symptoms were assessed using the Beck Youth Inventories. Associations between background factors, IQ and internalizing symptoms were explored in relation to having an NDD or not.

Results

We found that 47/80 children had at least one NDD. Children with a diagnosed NDD before study start (n = 30) had significantly more comorbidities than children diagnosed after the study screening (n = 17) (P = .01). Greater cognitive impairment was seen in children with NDD compared with children without an NDD (P = .01). Also, 33/73 participants self-reported substantial internalizing symptoms. At follow-up, 21/79 participants, in addition to NDD, had been diagnosed with another psychiatric disorder. Ten of these were children that had been diagnosed with an NDD before study start.

Conclusion

The overlap between NDD, cognitive deficits and psychiatric conditions in children with obesity is an important consideration for clinical practice. Screening for these conditions may be necessary when providing targeted interventions.

Maternal Pre-Pregnancy BMI and Gestational Weight Gain Are Associated with Preschool Children's Neuropsychological Outcomes in the APrON Cohort

This study examined the associations between maternal pre-pregnancy BMI and gestational weight gain (GWG) and children's neuropsychological outcomes at 3 to 5 years of age. A total of 379 women and their children from the Alberta Pregnancy Outcomes and Nutrition (APrON) study participated. Covariate-adjusted robust regressions examined associations between maternal pre-pregnancy BMI, GWG class, interaction terms, and child outcomes. Each unit increase in maternal BMI was linked to a 0.48-point decrement (95% CI: -0.75 to -0.21) in children's Full Scale IQ. Higher pre-pregnancy BMI was related to poorer performance on the other intelligence indexes (B = -0.35 to -0.47, 95% CIs: -0.75, -0.02) and lower performance on measures of language (B = -0.08 to -0.09, 95% CIs: -0.16, -0.02), motor skills (B = -0.08 to -0.11, 95% CIs: -0.18, -0.01), and executive function (B = -0.09 to -0.16, 95% CIs: -0.26, -0.01). GWG below the recommended range was associated with a 4.04-point decrement (95% CI: 7.89, -0.11) in Full Scale IQ, but better performance on a spatial working memory test (B = 0.27, 95% CI: 0.02, 0.52). GWG above the recommended range was associated with lower language (B = -0.79, 95% CI: -1.52, -0.06) and memory scores (B = -0.93, 95% CI: -1.64, -0.22). Interactions were found between pre-pregnancy BMI and GWG on measures of intelligence and executive function. Maternal pre-pregnancy BMI and GWG are related to children's performance in various neuropsychological domains and may interact to predict outcomes. Optimizing maternal health and weight prior to conception and during pregnancy may enhance children's neuropsychological outcomes.

The impact of COVID-19 on the psychological distress of youths in Japan: A latent growth curve analysis

BACKGROUND

This study expands on previous studies that have investigated the impact of the novel coronavirus disease (COVID-19) on mental health in two ways. We first model the change in mental health, then examine the various factors that predict changes in psychological distress.

METHOD

Longitudinal surveys were conducted once each in 2015, 2017, and 2019 on mothers and their children born between April 2000 and March 2001 (n = 1854), and three times in 2020 (February, July, and December) on the children in Japan. A latent growth curve model with four time points from December 2019 to December 2020 was used to depict the changes in the psychological distress of youths and to examine the factor associated with the level and change in psychological distress.

RESULTS

The psychological distress of youths increased from December 2019 to July 2020, especially among female youths, then decreased in December 2020. Initial health status and psychological traits were related to the initial level of psychological distress, but not the change. Gender was not related to the initial level of psychological distress but an increase in distress.

CONCLUSION

Although the effect size was small, gender was related to changes in distress during the COVID-19 pandemic. Other factors, such as health-related characteristics and personality traits, were associated with the level of distress before the pandemic but could not explain the changes in distress during the pandemic.

Relationships between Child Development at School Entry and Adolescent Health-A Participatory Systematic Review

The relationship between child development and adolescent health, and how this may be modified by socio-economic conditions, is poorly understood. This limits cross-sector interventions to address adolescent health inequality. This review summarises evidence on the associations between child development at school starting age and subsequent health in adolescence and identifies factors affecting associations. We undertook a participatory systematic review, searching electronic databases (MEDLINE, PsycINFO, ASSIA and ERIC) for articles published between November 1990 and November 2020. Observational, intervention and review studies reporting a measure of child development and subsequent health outcomes, specifically weight and mental health, were included. Studies were individually and collectively assessed for quality using a comparative rating system of stronger, weaker, inconsistent or limited evidence. Associations between child development and adolescent health outcomes were assessed and reported by four domains of child development (socio-emotional, cognitive, language and communication, and physical development). A conceptual diagram, produced with stakeholders at the outset of the study, acted as a framework for narrative synthesis of factors that modify or mediate associations. Thirty-four studies were included. Analysis indicated stronger evidence of associations between measures of socio-emotional development and subsequent mental health and weight outcomes; in particular, positive associations between early externalising behaviours and later internalising and externalising, and negative associations between emotional wellbeing and later internalising and unhealthy weight. For all other domains of child development, although associations with subsequent health were positive, the evidence was either weaker, inconsistent or limited. There was limited evidence on factors that altered associations. Positive socio-emotional development at school starting age appears particularly important for subsequent mental health and weight in adolescence. More collaborative research across health and education is needed on other domains of development and on the mechanisms that link development and later health, and on how any relationship is modified by socio-economic context.

Just a phase? Mapping the transition of behavioural problems from childhood to adolescence

PURPOSE

Young people change substantially between childhood and adolescence. Yet, the current description of behavioural problems does not incorporate any reference to the developmental context. In the current analysis, we aimed to identify common transitions of behavioural problems between childhood and adolescence.

METHOD

We followed 6744 individuals over 6 years as they transitioned from childhood (age 10) into adolescence (age 16). At each stage, we used a data-driven hierarchical clustering method to identify common profiles of behavioural problems, map transitions between profiles and identify factors that predict specific transitions.

RESULTS

Common profiles of behavioural problems matched known comorbidity patterns but crucially showed that the presentation of behavioural problems changes markedly between childhood and adolescence. While problems with hyperactivity/impulsivity, motor control and conduct were prominent in childhood, adolescents showed profiles of problems related to emotional control, anxiety and inattention. Transitions were associated with socio-economic status and cognitive performance in childhood CONCLUSION: We show that understanding behavioural difficulties and mental ill-health must take into account the developmental context in which the problems occur, and we establish key risk factors for specific negative transitions as children become adolescents.

Emotional intelligence and cognitive skills protecting mental health from stress and violence among Ghanaian youth

This study investigates the protective mental health function of high emotional intelligence (EI), and cognitive skills (CS) among Ghanaian adolescents when exposed to stressful life-events and violence. It examines, first, how exposure to stressful life-events and violent experiences is associated with mental health, indicated by depressive and psychological distress symptoms, and, second, whether EI and CS could serve as possible moderators between stress, violence and mental health problems. Participants were 415 Ghanaian secondary education students. They reported about their depressive symptoms (Bireleson), psychological distress (Strength and Difficult Questionnaire, SDQ), and emotional intelligence (Trait Emotional Intelligence Question-naire, TEIQue), cognitive skills (The Amsterdam Executive Function Inventory). They also reported their stressful life-events and violent experiences. Statistical analyses were conducted using structural equation modeling (SEM). As hypothesized, high level of stressful life events were associated with high levels of depressive symptoms and psychological distress. Yet violent experiences did not associate with mental health problems. Against hypothesis, high levels of EI and CS could not protect adolescents mental health from negative effects of stressful life events or violent experiences. A direct effects were found between low level of EI and CS and high level of mental health problems. The results are discussed in relations to psychological and cultural factors present in EI and CS in adolescence.

Childhood Socioeconomic Status and Late-Adulthood Mental Health: Results From the Survey on Health, Ageing and Retirement in Europe

Objectives

A growing literature acknowledges the association between childhood socioeconomic status (SES) and health in late adulthood (i.e., 50+). Less, however, is known about the association with mental health outcomes, such as depression. We use the Survey on Health, Ageing, and Retirement in Europe (SHARE) to analyze overall and gender-specific associations between childhood SES and late-adulthood depression.

Methods

Using life history and contemporaneous data from 21,989 SHARE respondents in combination with principal component analysis we construct indices of childhood SES. We measure late-adulthood depression using the EURO-D scale. Contemporaneous SES is operationalized as the logarithm of household equivalized income. We estimate associations using linear regression models.

Results

We document a positive association between childhood SES and the late-adulthood EURO-D score. The association persists even when allowing for contemporaneous SES. Zooming in on gender-specific associations reveals that the association for mental health is particularly pronounced for women.

Discussion

Our findings reveal the long-term association between childhood socioeconomic conditions and depression later in life, which persists even after taking into account current socioeconomic conditions and are stronger for women than for men. These results imply that boosting childhood socioeconomic conditions can potentially have effects lasting well beyond the childhood phase.

Health-related quality of life in congenital heart disease surgery in children and young adults: a systematic review and meta-analysis

BACKGROUND

As survival improves in the congenital heart disease (CHD) population, health-related quality of life (HRQOL) outcomes become increasingly important. While surgery improves survival, poor HRQOL occurs postoperatively and cardiac-related HRQOL outcomes are rarely reported.

OBJECTIVE

To conduct a systematic review and meta-analyses of general and cardiac-related HRQOL in CHD surgical children and young adults.

METHOD

Medline, CINAHL and EMBASE were searched. Quantitative designs with a minimum of 80% CHD surgical patients and mean age ≤18 years compared with healthy controls were included in the review. Data were analysed in RevMan V.5.3 using a random effects model.

OUTCOME MEASURES

General and cardiac-related HRQOL.

RESULTS

Studies (n=20) were conducted in high-income countries and included 3808 patients plus 2951 parental reports of patients. HRQOL was worse in postoperative patients with CHD versus healthy controls in all domains with the largest difference seen for physical function (standard mean difference (SMD) of -0.56, 95% CI -0.82 to -0.30). Cardiac-related HRQOL was worse in complex compared with simple CHD with the largest SMD (-0.60, 95% CI -0.80 to -0.40) for symptoms. Heterogeneity ranged from 0% to 90%.

CONCLUSIONS

CHD surgical patients have substantially worse HRQOL compared with age-matched healthy controls. Strategies should focus on improving HRQOL in this subgroup. Results may not be applicable to low/middle-income countries given the dearth of relevant research.

Prevalence, clinical correlates and IQ of suicidal ideation in drug naïve Chinese Han patients with major depressive disorder

BACKGROUND

Suicidal ideation (SI) is a common and serious clinical concern in people with major depressive disorder (MDD). Inconsistent evidence suggests that individuals with SI may have a lower measured intelligence quotient (IQ) than those without SI. The aims of this study were to examine SI prevalence and its associations with demographic, clinical variables and IQ in Chinese drug-naïve MDD patients.

METHODS

488 drug-naïve Chinese Han patients (male: 203, 41.6%) meeting a DSM-IV diagnosis of MDD were enrolled in a cross-sectional study involving seven hospitals. All participants were asked to complete a series of questionnaires, which include information on socio-demographic and clinical variables. The Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA) and Brief Psychiatric Rating Scale (BPRS) were also administered. Verbal IQ (VIQ), performance IQ (PIQ) and full-scale IQ (FIQ) scores were measured using the Chinese version of the Wechsler Adult Intelligence Scale-Ⅲ (WAIS-Ⅲ). We categorized patients with SI based on a cut-off score of ≥3 on HAMD item 3.

RESULTS

An estimated prevalence 32.8% (160/488) of drug-naïve MDD patients experienced SI during the current episode of illness. Patients with SI were more likely to be divorced (x²= 6.93, p = 0.031), male (x²= 6.04, p = 0.014), had higher severity of depression and anxiety symptoms (t = -8.14, p < 0.001, t = -3.28, p < 0.001, respectively), comorbid psychotic features (t = -5.71, p < 0.001), and lower FIQ levels (t = -4.21, p < 0.001), when compared to patients without SI. Using logistic regression analysis and adjusting for confounding variables, the following variables were independently associated with SI: divorced marital status compared to married (OR=4.674, 95% CI: 1.676~13.036), severity of depression symptoms (OR=1.312, 95% CI: 1.196~1.440), psychotic features (OR=1.044; 1.012~1.077), and FIQ /PIQ levels which expressed in OR per SD increase in IQ score (OR=0.740, 95% CI: 0.561~0.977; OR=0.744, 95% CI: 0.557~0.994, respectively).

LIMITATIONS

A cross-sectional study which did not assess the influence of severity of SI.

CONCLUSIONS

The prevalence of SI in drug-naive Chinese patients with MDD is high, and associated with marital status, severity of depression, psychotic features and measured IQ. Further research is needed to further explore these and other potentially relevant risk factors which might affect clinical outcomes.

Relationship between leisure time physical activity, sedentary behaviour and symptoms of depression and anxiety: evidence from a population-based sample of Canadian adolescents

BACKGROUND

Physical and sedentary activities have been identified as potentially modifiable risk factors for many diseases, including mental illness, and may be effective targets for public health policy and intervention. However, the relative contribution of physical activity versus sedentary behaviour to mental health is less clear. This study investigated the cross-sectional association between physical activity, sedentary activity and symptoms of depression and anxiety at age 14-15 in the National Longitudinal Survey of Children and Youth (NLSCY).

METHODS

Respondents aged 14-15 years between 1996 and 2009 who reported on symptoms of depression in the NLSCY were included (n=9702). Multinomial logistic regression was used to assess the relationship between physical and sedentary activity and symptoms of depression and anxiety. Joint models including both physical and sedentary activity were also explored. Models were adjusted for sex, ethnicity, immigration status, family income, parental education, recent major stressful life events and chronic health conditions.

RESULTS

The odds of having moderate and severe symptoms of depression and anxiety compared with no symptoms was 1.43 (1.11 to 1.84) and 1.88 (1.45 to 2.45) times higher, respectively, in physically inactive youth relative to physically active youth. The odds of having moderate and severe symptoms of depression and anxiety compared with no symptoms was 1.38 (1.13 to 1.69) and 1.31 (1.02 to 1.69) times higher, respectively, in sedentary youth relative to non-sedentary youth. In joint models including both physical and sedentary activity, sedentary activity was not consistently associated with symptoms of depression and anxiety.

CONCLUSIONS

Both physical inactivity and sedentary activity appear to be significantly related to symptoms of depression and anxiety. The importance of distinguishing these two behaviours has relevance for research as well as policies targeting physical activity and mental health in youth.

Cognitive Performance in Adolescence: Links With Early Maternal Stimulation and Children's Anxious Behaviors

This study tested a developmental model of cognitive performance in adolescence and explored potential mechanisms explaining the relations of early maternal stimulation and children's anxious behaviors with adolescents' cognitive performance. We utilized the NICHD SECCYD dataset (n = 1,112). Measures included questionnaires, coded observations, and self-report measures from infancy to adolescence. Results revealed that children who experienced greater early maternal stimulation and less anxious behaviors had better cognitive performance at age 15. Children's English self-efficacy, the quality of child-teacher relationships, and children's behavioral classroom engagement in middle childhood mediated the relation between early maternal stimulation and adolescent cognitive performance. Identifying pathways from earlier maternal and children's characteristics to children's later cognitive performance is an important step toward further understanding why early precursors have a long lasting impact on cognitive performance, and has implications for educational settings.

Self-Esteem Trajectories and Their Social Determinants in Adolescents With Different Levels of Cognitive Ability

This study examines the development of self-esteem in a sample of 138 Australian adolescents (90 males; 48 females) with cognitive abilities in the lowest 15% (L-CA) and a matched sample of 556 Australian adolescents (312 males; 244 females) with average to high levels of cognitive abilities (A/H-CA). These participants were measured annually (Grade 7 to 12). The findings showed that adolescents with L-CA and A/H-CA experience similar high and stable self-esteem trajectories that present similar relations with key predictors (sex, school usefulness and dislike, parenting, and peer integration). Both groups revealed substantial gender differences showing higher levels of self-esteem for adolescent males remaining relatively stable over time, compared to lower levels among adolescent females which decreased until midadolescence before increasing back.

Characterizing neurocognitive impairment in young people with major depression: state, trait, or scar?

BACKGROUND

Major depressive disorder (MDD) affects a quarter of adolescents and young adults and is associated with the greatest global burden of disease in this population. There is a growing literature, mostly in adults, showing that significant neurocognitive impairments are common in MDD. It remains unclear whether these impairments are pre-existing trait markers of MDD, state-related impairments that fluctuate with depressive symptoms, or 'scar' impairments that worsen with illness progression. The aim of this study is to provide a conceptual framework for understanding MDD and neurocognitive impairment in adolescence and young adulthood (ages 12-25 years).

METHOD

Examination of the evidence for neurocognitive deficits as trait, state, and scar features of MDD according to different study designs (family studies, premorbid studies, current depression, remitted depression, and longitudinal studies with repeated assessment) was conducted.

RESULTS

The few premorbid and family studies conducted in youth provide equivocal evidence for neurocognitive impairments as trait markers of MDD. The presence of state-based neurocognitive impairment remains unclear as evidence comes mostly from cross-sectional studies. There are a limited, but growing number of longitudinal studies with repeated neurocognitive assessment in youth. Studies that examined neurocognition prior to the onset of MDD and with long-term follow-up provide tentative evidence for neurocognitive scarring.

CONCLUSION

Neurocognitive impairment is a feature of MDD in adolescents and young adults. To better understand the nature, timing, and pattern of impairment, longitudinal studies that examine neurocognition before and after the development of full-threshold MDD, including following recurrence are needed. This knowledge will have important implications for mechanisms, prevention, and treatment of MDD in youth.

Intelligence in youth and mental health at age 50

BACKGROUND

Few cognitive epidemiology studies on mental health have focused on the links between pre-morbid intelligence and self-reports of common mental disorders, such as depression, sleep difficulties, and mental health status. The current study examines these associations in 50-year-old adults.

METHODS

The study uses data from the 5793 participants in the National Longitudinal Survey of Youth 1979 cohort (NLSY-79) who responded to questions on mental health at age 50 and had IQ measured with the Armed Forces Qualification Test (AFQT) when they were aged between 15 and 23 years in 1980. Mental health outcomes were: life-time diagnosis of depression; the mental component score of the 12-item short-form Health Survey (SF-12); the 7-item Center for Epidemiological Studies Depression Scale (CES-D); and a summary measure of sleep difficulty.

RESULTS & CONCLUSION

Higher intelligence in youth is associated with a reduced risk of self-reported mental health problems at age 50, with age-at-first-interview and sex adjusted Bs as follows: CES-depression (B = - 0.16, C.I. - 0.19 to - 0.12, p < 0.001), sleep difficulties (B = - 0.11, C.I. - 0.13 to - 0.08, p < 0.001), and SF-12 mental health status (OR = 0.78, C.I. 0.72 to 0.85, p < 0.001; r = - 0.03 p = 0.075). Conversely, intelligence in youth is linked with an increased risk of receiving a diagnosis of depression by the age of 50 (OR 1.11, C.I. 1.01 to 1.22, p = 0.024; r = 0.03, p = 0.109). No sex differences were observed in the associations. Adjusting for adult SES accounted for most of the association between IQ and the mental health outcomes, except for having reported a diagnosis of depression, in which case adjusting for adult SES led to an increase in the size of the positive association (OR = 1.32, C.I. 1.16 to 1.51, p < 0.001).

Cognitive ability in childhood and the chronicity and suicidality of depression

BACKGROUND

There is inconsistent evidence regarding the influence of general cognitive abilities on the long-term course of depression.

AIMS

To investigate the association between general childhood cognitive abilities and adult depression outcomes.

METHOD

We conducted a cohort study using data from 633 participants in the New England Family Study with lifetime depression. Cognitive abilities at age 7 were measured using the Wechsler Intelligence Scale for Children. Depression outcomes were assessed using structured diagnostic interviews administered up to four times in adulthood between ages 17 and 49.

RESULTS

In analyses adjusting for demographic factors and parental psychiatric illness, low general cognitive ability (i.e. IQ<85 v. IQ>115) was associated with recurrent depressive episodes (odds ratio (OR) = 2.19, 95% CI 1.20-4.00), longer episode duration (rate ratio 4.21, 95% CI 2.24-7.94), admission to hospital for depression (OR = 3.65, 95% CI 1.34-9.93) and suicide ideation (OR = 3.79, 95% CI 1.79-8.02) and attempt (OR = 4.94, 95% CI 1.67-14.55).

CONCLUSIONS

Variation in cognitive abilities, predominantly within the normal range and established early in childhood, may confer long-term vulnerability for prolonged and severe depression. The mechanisms underlying this vulnerability need to be established to improve the prognosis of depression among individuals with lower cognitive abilities.

The role of timing of maltreatment and child intelligence in pathways to low symptoms of depression and anxiety in adolescence

Research indicates that childhood maltreatment is strongly associated with high levels of adolescent depression and anxiety symptoms. Using LONGSCAN data and taking into account the range of family characteristics related to adversity (poverty, primary caregiver substance abuse) and protective factors (living with biological mother and father), the present study assessed the complex resilience process in which child intelligence (age 6) mediated the relationship between early childhood maltreatment (age 0-4) and adolescent symptoms of depression and anxiety (age 14). We also assessed if mid (age 6-8) and late (age 10-12) childhood maltreatment moderated this mediation. We found that mid-childhood intelligence mediated the negative effect of early childhood maltreatment (age 0-4) on anxiety symptoms (age 14), but not on depressive symptoms (age 14). We also found the effect of timing of maltreatment: early childhood maltreatment (age 0-4) predicted more anxiety symptoms in adolescence, whereas late childhood/early adolescent (age 10-12) maltreatment predicted more symptoms of depression in adolescence. In addition, mid (age 6-8) and late (age 10-12) childhood maltreatment dampened the protective effect of IQ (age 6) against anxiety (age 14). In sum, current evidence shows that low anxiety and depression symptoms in adolescence following childhood maltreatment was achieved through different pathways, and that early and late childhood/early adolescence were more sensitive periods for development of psychopathology related to depression and anxiety in adolescence.

Trajectories of depressive symptoms during the transition to young adulthood: the role of chronic illness

BACKGROUND

Little is known about the natural course of depressive symptoms among youth with chronic illness during their transition from adolescence to young adulthood.

METHODS

A representative epidemiological sample of 2825 youth aged 10-11 years from the National Longitudinal Survey of Children and Youth were followed until 24-25 years of age. Presence of chronic illness was measured using self-report and symptoms of depression were assessed using the Center for Epidemiological Studies Depression Scale. Multilevel modeling was used to investigate trajectories of depressive symptoms, adjusting for family environment and sociodemographic characteristics during the transition to young adulthood.

RESULTS

Trajectories showed cubic change over time - increasing from early to mid-adolescence, decreasing to early young adulthood, increasing again to late young adulthood. Youth with chronic illness (n=753) had significantly less favorable trajectories and significantly higher proportions of clinically relevant depressive symptoms over time compared to their peers without chronic illness (n=2072).

LIMITATIONS

This study is limited by selective attrition, self-reported chronic illness and no assessment of illness severity, and mediating effects of family environment factors could not be examined.

CONCLUSIONS

Findings support the diathesis-stress model; chronic illness negatively influenced depressive symptoms trajectories, such that youth with chronic illness had higher depression scores and less favorable trajectories over time. The health and school system are uniquely positioned to support youth with chronic illness navigate this developmental period in an effort to prevent declines in mental health.

Time trends in symptoms of mental illness in children and adolescents in Canada

BACKGROUND

Existing research and media reports convey conflicting impressions of trends in the prevalence of mental illness. We sought to investigate trends in the prevalence of symptoms of mental illness in a large population-based cohort of Canadian children and adolescents.

METHODS

We obtained population-based data from the National Longitudinal Survey of Children and Youth. Every 2 years, participants completed self-reported measures of mental illness indicators, including conduct disorder, hyperactivity, indirect aggression, suicidal behaviour, and depression and anxiety. We analyzed trends in mean scores over time using linear regression.

RESULTS

We evaluated 11 725 participants aged 10-11 years from cycles 1 (1994/95) through 6 (2004/05), 10 574 aged 12-13 years from cycles 2 (1996/97) through 7 (2006/07), and 9835 aged 14-15 years from cycles 3 (1998/99) through 8 (2008/09). The distribution of scores on depression and anxiety, conduct and indirect aggression scales remained stable or showed small decreases over time for participants of all ages. The mean hyperactivity score increased over time in participants aged 10-11 years (change per 2-year cycle: 0.16, 95% CI 0.02 to 0.12) and those aged 12-13 years (0.13, 95% CI 0.09 to 0.18). Over time, fewer participants aged 12-13 years (0.40% per cycle, 95% CI -0.78 to -0.07) and aged 14-15 years (0.56% per cycle, 95% CI -0.91 to -0.23) reported attempting suicide in the previous 12 months.

INTERPRETATION

With the exception of hyperactivity, the prevalence of symptoms of mental illness in Canadian children and adolescents has remained relatively stable from 1994/95 to 2008/09. Conflicting reports of escalating rates of mental illness in Canada may be explained by differing methodologies between studies, an increase in treatment-seeking behaviour, or changes in diagnostic criteria or practices.