Psychiatric disorders in the relatives of depressed probands. I. Comparison of prepubertal, adolescent and early adult onset cases

Reactive Depression: Lost in Translation!

The old classification of depression as reactive and endogenous, which are still observed in clinical practice, both cannot be accommodated under the current rubric of major depression. This is because psychiatric nosology under the Diagnostic and Statistical Manual of Mental Disorders (DSM) and its latest fifth edition (DSM-V) is still descriptive and not etiologic. The aim of this review was to revisit reactive and endogenous categories of depression from the perspective of today's understanding of etiological pathways. From an epigenetic perspective, the old dichotomy of reactive versus endogenous is interrelated through the impact of the environment (e.g., stress). This includes familial or prenatal depression, where the environmental impact is before birth, or childhood depression, where the early life stress is the precipitating factor to genetic susceptibility. In conclusion, searching for both environmental impact (e.g., stressors) and genetic predispositions in depression, even at a clinical level, could help clinicians with better therapeutic decisions.

Characterizing Developmental Trajectories and the Role of Neuropsychiatric Genetic Risk Variants in Early-Onset Depression

Importance

Depression often first manifests in adolescence. Thereafter, individual trajectories vary substantially, but it is not known what shapes depression trajectories in youth. Adult studies suggest that genetic risk for schizophrenia, a psychiatric disorder with a neurodevelopmental component, may contribute to an earlier onset of depression.

Objective

To test the hypothesis that there are distinct trajectories of depressive symptoms and that genetic liability for neurodevelopmental psychiatric disorders (eg, schizophrenia, attention deficit/hyperactivity disorder [ADHD]), as well as for major depressive disorder (MDD), contribute to early-onset depression.

Design, Setting, and Participants

The Avon Longitudinal Study of Parents and Children is an ongoing, prospective, longitudinal, population-based cohort that has been collecting data since September 6, 1990, including data on 7543 adolescents with depressive symptoms at multiple time points. The present study was conducted between November 10, 2017, and August 14, 2018.

Main Outcomes and Measures

Trajectories based on self-reported depressive symptoms dichotomized by the clinical cutpoint; MDD, schizophrenia, and ADHD polygenic risk score (PRS) were predictors.

Results

In 7543 adolescents with depression data on more than 1 assessment point between a mean (SD) age of 10.64 (0.25) years and 18.65 (0.49) years (3568 [47.3%] male; 3975 [52.7%] female), 3 trajectory classes were identified: persistently low (73.7%), later-adolescence onset (17.3%), and early-adolescence onset (9.0%). The later-adolescence-onset class was associated with MDD genetic risk only (MDD PRS: odds ratio [OR], 1.27; 95% CI, 1.09-1.48; P = .003). The early-adolescence-onset class was also associated with MDD genetic risk (MDD PRS: OR, 1.24; 95% CI, 1.06-1.46; P = .007) but additionally with genetic risk for neurodevelopmental disorders (schizophrenia PRS: OR, 1.22; 95% CI, 1.04-1.43; P = .01; ADHD PRS: OR, 1.32; 95% CI, 1.13-1.54; P < .001) and childhood ADHD (χ21 = 6.837; P = .009) and neurodevelopmental traits (pragmatic language difficulties: OR, 1.31; P = .004; social communication difficulties: OR, 0.68; P < .001).

Conclusions and Relevance

The findings of this study appear to demonstrate evidence of distinct depressive trajectories, primarily distinguished by age at onset. The more typical depression trajectory with onset of clinically significant symptoms at age 16 years was associated with MDD genetic risk. The less-common depression trajectory, with a very early onset, was particularly associated with ADHD and schizophrenia genetic risk and, phenotypically, with childhood ADHD and neurodevelopmental traits. Findings are consistent with emerging evidence for a neurodevelopmental component in some cases of depression and suggest that the presence of this component may be more likely when the onset of depression is very early.

Age of onset and family history as indicators of polygenic risk for major depression

BACKGROUND

The extent to which earlier age of onset (AO) is a reflection of increased genetic risk for major depression (MD) is still unknown. Previous biometrical research has provided mixed empirical evidence for the genetic overlap of AO with MD. If AO is demonstrated to be relevant to molecular polygenic risk for MD, incorporation of AO as a phenotype could enhance future genetic studies.

METHODS

This research estimated the SNP-based heritability of AO in the China, Oxford and VCU Experimental Research on Genetic Epidemiology (CONVERGE) case-control sample (N = 9,854; MD case, n = 4,927). Common single nucleotide polymorphism heritability of MD was also examined across both high and low median-split AO groups, and best linear unbiased predictor (BLUP) scores of polygenic risk, in split-halves, were used to predict AO. Distributions of genetic risk across early and late AO were compared, and presence of self-reported family history (FH) of MD was also examined as a predictor of AO.

RESULTS

AO was not significantly heritable and polygenic risk derived from the aggregated effects of common genetic variants did not significantly predict AO in any analysis. AO was modestly but significantly lower in cases with a first-degree genetic FH of MD.

CONCLUSIONS

Findings indicate that AO is associated with greater self-reported genetic risk for MD in cases, yet not associated with common variant polygenic risk for MD. Future studies of early MD may benefit more from the examination of important moderating variables such as early life events.

Correlates of Childhood vs. Adolescence Internalizing Symptomatology from Infancy to Young Adulthood

In light of its associations with child and adolescent health and well-being, there remains a need to better understand the etiological underpinnings and developmental course of internalizing symptomatology in children and adolescents. This study leveraged intensive longitudinal data (N = 959; 49.6 % females) to test the hypothesis that internalizing symptoms in childhood may be driven more strongly by family experiences whereas internalizing symptoms in adolescence may derive more uniquely from familial loading for affective disorders (i.e., maternal depression). We evaluated the relative contributions of (a) family experiences (b) maternal depression, and (c) peer influences in testing this hypothesis. The results indicated that family predictors were more strongly correlated with childhood (relative to adolescent) internalizing symptoms. In contrast to previous findings, maternal depression also exhibited stronger associations with childhood internalizing symptoms. Although often overlooked in theories concerning potential differential origins of childhood vs. adolescent internalizing symptomatology, peer experiences explained unique variation in both childhood and adolescent internalizing problems.

Effect of Environmental Risk and Externalizing Comorbidity on Internalizing Problems Among Economically Disadvantaged African American Youth

This study examined effects of racial discrimination, community violence, and stressful life events on internalizing problems among African American youth from high poverty neighborhoods (N = 607; 293 boys; Mage = 16.0 years, SD = 1.44 years). Mediated effects via externalizing problems on these relations were also examined, given the high comorbidity rate between internalizing and externalizing problems. Externalizing problems partially mediated the effect of stressful life events on internalizing problems and fully mediated the effect of racial discrimination for boys but not for girls. Exposure to violence had a significant indirect effect on internalizing problems via externalizing problems. The findings call for greater attention to internalizing problems among African American youth and pathways to internalizing problems via externalizing problems.

Profiling depression in childhood and adolescence: the role of conduct problems

BACKGROUND

Depression is typically more common in females and rates rise around puberty. However, studies of children and adolescents suggest that depression accompanied by conduct problems may represent a different subtype not characterised by a female preponderance, with differing risk factors and genetic architecture compared to pure-depression. This study aimed to identify aetiologically distinct profiles of depressive symptoms, distinguished by the presence or absence of co-occurring conduct problems.

METHODS

Latent profile analysis was conducted on a school sample of 1648 children (11-12 years) and replicated in a sample of 2006 twins (8-17 years).

RESULTS

In both samples pure-depressive and conduct-depressive profiles were identified. The pure-depressive profile was associated with female gender, while the conduct-depressive profile was associated with lower cognitive ability but not with gender. Twin analyses indicated possible differences in genetic aetiology.

CONCLUSIONS

There was evidence for aetiologically heterogeneous depression symptom profiles based on the presence or absence of co-occurring conduct problems.

The specificity of the familial aggregation of early-onset bipolar disorder: A controlled 10-year follow-up study of offspring of parents with mood disorders

BACKGROUND

Two major sources of heterogeneity of mood disorders that have been demonstrated in clinical, family and genetic studies are the mood disorder subtype (i.e. bipolar (BPD) and major depressive disorder (MDD)) and age of onset of mood episodes. Using a prospective high-risk study design, our aims were to test the specificity of the parent-child transmission of BPD and MDD and to establish the risk of psychopathology in offspring in function of the age of onset of the parental disorder.

METHODS

Clinical information was collected on 208 probands (n=81 with BPD, n=64 with MDD, n=63 medical controls) as well as their 202 spouses and 372 children aged 6-17 years at study entry. Parents and children were directly interviewed every 3 years (mean duration of follow-up=10.6 years). Parental age of onset was dichotomized at age 21.

RESULTS

Offspring of parents with early onset BPD entailed a higher risk of BPD HR=7.9(1.8-34.6) and substance use disorders HR=5.0(1.1-21.9) than those with later onset and controls. Depressive disorders were not significantly increased in offspring regardless of parental mood disorder subtype or age of onset.

LIMITATIONS

Limited sample size, age of onset in probands was obtained retrospectively, age of onset in co-parents was not adequately documented, and a quarter of the children had no direct interview.

CONCLUSIONS

Our results provide support for the independence of familial aggregation of BPD from MDD and the heterogeneity of BPD based on patterns of onset. Future studies should further investigate correlates of early versus later onset BPD.

Parental depressive symptoms and children's school attendance and emergency department use: a nationally representative study

We sought to assess the association between parental depressive symptoms and school attendance and emergency department (ED) use among children with and without chronic health conditions. Secondary analysis of the 1997-2004 National Health Interview Survey, a nationally representative survey. Parental depressive symptoms were measured by three questions assessing sadness, hopelessness, or worthlessness in the past month. Children with and without asthma or attention-deficit/hyperactivity disorder (ADHD) were identified, and their school attendance and ED visits were reported by adult household respondents. Children with information on parental depressive symptoms, health conditions, and services use were eligible. We incorporated weights available in the survey for each eligible child to reflect the complex sampling design. 104,930 eligible children were identified. The point prevalence of parental depressive symptoms was low (1.8 %, 95 % CI 1.7-2.0), but greater among children with asthma (2.7 %, 95 % CI 2.4-3.0) and ADHD (3.8 %, 95 % CI 3.2-4.4) than among other children (1.6 %, 95 % CI 1.5-1.7). After adjustment for potential confounders, children whose parents reported depressive symptoms most or all of the time were more likely to report an ED visit (adjusted incident rate ratio [IRR] 1.18, 95 % CI 1.06-1.32) or school absence (adjusted IRR 1.36, 95 % CI 1.14-1.63) than children whose parents did not. The effect of parental depressive symptoms was not modified by child health conditions. Parental depressive symptoms were adversely associated with school attendance and ED use in children. These results suggest the importance of measuring depressive symptoms among adult caregivers of children.

Vulnerability to depression: a moderated mediation model of the roles of child maltreatment, peer victimization, and serotonin transporter linked polymorphic region genetic variation among children from low socioeconomic status backgrounds

Child maltreatment, peer victimization, and a polymorphism of the serotonin transporter gene (5-HTTLPR) were examined as predictors of depressive symptomatology. Children (M age = 11.26, SD = 1.65), including 156 maltreated and 145 nonmaltreated children from comparable low socioeconomic backgrounds, provided DNA samples and self-reports of relational peer victimization, overt peer victimization, and depressive symptoms. Path analysis showed that relational and overt victimization mediated the association between child maltreatment and depressive symptoms. Bootstrapping procedures were used to test moderated mediation and demonstrated that genotype moderated the indirect effects of relational and overt victimization on child depressive symptoms, such that victimized children with the long/long variation were at an increased risk for depressive symptoms compared to victimized children carrying a short allele. Results highlight the utility of examining process models that incorporate biological and psychological factors contributing to the development of depressive symptomatology and provide direction toward understanding and promoting resilience among high-risk youth from a multiple levels of analysis approach.

Major depressive disorder in a Kenyan youth sample: relationship with parenting behavior and parental psychiatric disorders

BACKGROUND

Studies on mental health problems during childhood and youth development phases have reported that families of children diagnosed with a depressive disorder tend to be dysfunctional. These dysfunctions have been shown to be mediating factors for children to develop psychiatric disorders in the future.

OBJECTIVE

This study was designed to investigate whether perceived parenting behavior and parental psychiatric disorders have any relationship with youth presenting with major depressive disorder.

METHODOLOGY

The study sample had a total number of 250 purposely selected youth attending the Youth Clinic at Kenyatta National Hospital in Nairobi.

RESULTS

This study found associations between major depressive disorders (MDD) in the youth and co-morbid psychiatric disorders among the youth: conduct disorder (OR = 2.93, 95% CI 1.04 to 8.26, p = 0.035), any anxiety disorder (OR = 2.41, 95% CI 1.20 to 4.87, p = 0.012), drug abuse (OR = 3.40, 95% CI 2.01 to 5.76, p < 0.001), alcohol use (OR = 3.29, 95% CI 1.94 to 5.57, p < 0.001), and suicidal behavior (OR = 5.27, 95% CI 2.39 to 11.66, p < 0.001). The results also indicate that a higher proportion of youth between 16 and 18 years had major depressive disorder than the youth below 16 years or above 18 years of age (OR = 2.66, 95% CI 1.40 to 5.05, p = 0.003). Multivariate analysis shows that both rejecting maternal behavior (AOR = 2.165, 95% CI 1.060 to 4.422, p = 0.003) and maternal MDD (AOR = 5.27, 95% CI 1.10 to 14.76, p < 0.001) are associated with MDD in youth.

CONCLUSION

Negative maternal parenting behavior and maternal depressive disorder are associated with major depressive disorder in children.

Suicidal behaviour among youths associated with psychopathology in both parents and youths attending outpatient psychiatric clinic in Kenya

BACKGROUND

Suicide is a major cause of death among youths particularly with psychiatric, alcohol abuse and substance abuse disorders. There are relatively few studies on the relationship between psychiatric and substance abuse disorders with suicidal behaviour from low-income countries. This study examines the relationship between suicidal behaviour and co-existing psychiatric or substance disorders among youths and depressive and alcohol use disorders in their parents.

METHOD

The study sample had 678 respondents: 250 youths and 226 and 202 biological mothers and fathers, respectively.

RESULTS

This study found a significant statistical association between depressive (p < 0.001), alcohol abuse (p <0.001) and substance abuse (p < 0.001) disorders and suicidal behaviour in youths. There was a significant relationship between maternal depressive disorder (p < 0.001) and perceived maternal rejecting parenting behaviour (p < 0.001) with suicidal behaviour in youths. There was a greater odds of a youth with two to three (odds ratio (OR) = 3.63; p = 0.009) and four or more (OR = 8.23; p < 0.001) co-existing psychiatric disorders to have suicidal behaviour than a youth with only one psychiatric disorder. The results also indicate that a higher proportion of youths between ages 16-18 years had suicidal behaviour than youths below 16 years or above 18 years of age (p = 0.004).

CONCLUSION

These findings suggest that youths with psychiatric and substance abuse disorders have mothers living with a depressive disorder. Also, perceived maternal rejecting parenting behaviour contributes significantly to the development of suicidal behaviour later in adolescent years.

The current state of play on the molecular genetics of depression

BACKGROUND

It has been well established that both genes and non-shared environment contribute substantially to the underlying aetiology of major depressive disorder (MDD). A comprehensive overview of genetic research in MDD is presented. Method Papers were retrieved from PubMed up to December 2011, using many keywords including: depression, major depressive disorder, genetics, rare variants, gene-environment, whole genome, epigenetics, and specific candidate genes and variants. These were combined in a variety of permutations.

RESULTS

Linkage studies have yielded some promising chromosomal regions in MDD. However, there is a continued lack of consistency in association studies, in both candidate gene and genome-wide association studies (GWAS). Numerous factors may account for variable results including the use of different diagnostic approaches, small samples in early studies, population stratification, epigenetic phenomena, copy number variation (CNV), rare variation, and phenotypic and allelic heterogeneity. The conflicting results are also probably, in part, a consequence of environmental factors not being considered or controlled for.

CONCLUSIONS

Each research group has to identify what issues their sample may best address. We suggest that, where possible, more emphasis should be placed on the environment in molecular behavioural genetics to identify individuals at environmental high risk in addition to genetic high risk. Sequencing should be used to identify rare and alternative variation that may act as a risk factor, and a systems biology approach including gene-gene interactions and pathway analyses would be advantageous. GWAS may require even larger samples with reliably defined (sub)phenotypes.

Key Characteristics of Major Depressive Disorder Occurring in Childhood, Adolescence, Emerging Adulthood, Adulthood

This paper summarizes characteristics of major depressive disorder (MDD) in the Oregon Adolescent Depression Project, using data from 816 participants (56% female; 89% White). Contrasting four developmental periods (Childhood [5-12.9], Adolescence [13-17.9], Emerging Adulthood [18-23.9], Adulthood [24-30]), we examine MDD incidence/recurrence, gender, comorbidity, duration, and suicide attempts across periods. MDD first incidence was lower in Childhood compared to subsequent periods, and higher in Emerging Adulthood than Adulthood. Cumulative incidence was 51%. Recurrence was lower during Childhood than remaining periods, which were comparable. Female gender predicted first incident MDD in all four periods but was unassociated with recurrence. Comorbidity rates were comparable across periods. MDD duration was greater in Childhood than remaining periods. Suicide attempt rates were significantly higher during Adolescence than either Emerging Adulthood or Adulthood. Depression research should focus on MDD during Emerging Adulthood, adolescent suicidal behavior, the continuing role of gender into adulthood, and the ubiquity of MDD.

Increased activity imbalance in fronto-subcortical circuits in adolescents with major depression

Background

A functional discrepancy exists in adolescents between frontal and subcortical regions due to differential regional maturational trajectories. It remains unknown how this functional discrepancy alters and whether the influence from the subcortical to the frontal system plays a primacy role in medication naïve adolescent with major depressive disorder (MDD).

Methodology/Principal Findings

Eighteen MDD and 18 healthy adolescents were enrolled. Depression and anxiety severity was assessed by the Short Mood and Feeling Questionnaire (SMFQ) and Screen for Child Anxiety Related Emotional Disorders (SCARED) respectively. The functional discrepancy was measured by the amplitude of low-frequency fluctuations (ALFF) of resting-state functional MRI signal. Correlation analysis was carried out between ALFF values and SMFQ and SCARED scores. Resting brain activity levels measured by ALFF was higher in the frontal cortex than that in the subcortical system involving mainly (para) limbic-striatal regions in both HC and MDD adolescents. The difference of ALFF values between frontal and subcortical systems was increased in MDD adolescents as compared with the controls.

Conclusions/Significance

The present study identified an increased imbalance of resting-state brain activity between the frontal cognitive control system and the (para) limbic-striatal emotional processing system in MDD adolescents. The findings may provide insights into the neural correlates of adolescent MDD.

Familial transmission of depression and antisocial behavior symptoms: disentangling the contribution of inherited and environmental factors and testing the mediating role of parenting

BACKGROUND

Genetic and environmental influences on child psychopathology have been studied extensively through twin and adoption designs. We offer a novel methodology to examine genetic and environmental influences on the intergenerational transmission of psychopathology using a sample of parents and children conceived through in vitro fertilization (IVF).

METHOD

The sample included families with children born through IVF methods, who varied as to whether the child was genetically related or unrelated to the rearing mother and father (mother genetically related, n=434; mother genetically unrelated, n=127; father genetically related, n=403; father genetically unrelated, n=156). Using standardized questionnaires, mothers and fathers respectively reported on their own psychopathology (depression, aggression), their parenting behavior toward their child (warmth, hostility) and their child's psychopathology (depression, aggression). A cross-rater approach was used, where opposite parents reported on child symptoms (i.e. fathers reported on symptoms for the mother-child dyad, and vice versa).

RESULTS

For mother-child dyads, a direct association between mother depression and child depression was observed among genetically unrelated dyads, whereas a fully mediated path was observed among genetically related dyads through mother-to-child hostility and warmth. For father-child dyads, direct and mediated pathways were observed for genetically related father-child dyads. For aggression, the direct association between parent aggression and child aggression was fully mediated by parent-to-child hostility for both groups, indicating the role of parent-to-child hostility as a risk mechanism for transmission.

CONCLUSIONS

A differential pattern of genetic and environmental mediation underlying the intergenerational transmission of psychopathology was observed among genetically related and genetically unrelated father-child and mother-child dyads.

Can basic risk research help in the prevention of childhood and adolescent depression? Examining a cognitive and emotional regulation approach

This paper aims to highlight ways in which basic research findings in the field of childhood and adolescent depression can help to inform and refine preventive intervention efforts. We selectively review basic research evidence from community, clinical, and high-risk populations that identifies cognitive mechanisms (thought processes and reactions to negative affect) and emotional regulation as key processes involved in the onset and maintenance of depression. We focus on cognitive and emotional mechanisms in order to allow comparability with the majority of current preventive interventions. A range of basic research strategies and studies are then suggested that could be employed to help the development and refinement of prevention strategies. These include the need for prospective longitudinal studies to identify causal risk and protective factors, an integration of research approaches and methods, and a focus on understanding potential aetiological heterogeneity between childhood and adolescent depression.

Genetics of childhood and adolescent depression: insights into etiological heterogeneity and challenges for future genomic research

There is heterogeneity between depression in childhood, adolescence and adulthood in terms of the gender composition of affected cases, prevalence, rates of recurrence and risk factors. This raises complex questions for refining the phenotype for molecular genetic studies of depression and the selection of appropriate proband groups. This article aims to provide a review of issues arising from family, twin and adoption studies of relevance to molecular genetic studies, and to summarize molecular genetic findings on childhood/adolescent depression. While retrospective studies of adults suggest greater familial aggregation among those with an earlier age of onset, prospective studies do not confirm this association. In fact, taken together, evidence from family and twin studies suggests that prepubertal depression is more strongly associated with psychosocial adversity, is less heritable and shows lower levels of continuity with adult depression than either adolescent or adult depression. Adolescent depressive symptoms and disorder show similar levels of heritability to depression in adult life, although there is only one twin study of adolescent depressive disorder, and heritability estimates of depressive symptoms vary widely between studies. This variability in heritability estimates is partly attributable to age and informant effects. Adoption studies and other intergenerational transmission designs show that the transmission of depression between parents and children involves genetic and environmental processes, with converging evidence that environmental processes are most important. Molecular genetic studies of childhood/adolescent depression have to date used a candidate gene approach and focused on genes already examined in adult studies. Prospective longitudinal studies of community and high-risk samples are needed to clarify issues of etiological heterogeneity in depression, and these should in turn inform the planning of molecular genetic studies.

Psychological factors linked to self-reported depression symptoms in late adolescence

BACKGROUND

The likelihood of developing depression increases throughout adolescence.

AIMS

Understanding the relative contribution of psychosocial and cognitive variables to depressive symptoms during the transitional stage of late adolescence should increase the scope for effective prevention and intervention.

METHOD

The Inventory of Parent and Peer Attachment (IPPA), Adolescents' Cognitive Style (ACSQ), Relationship Rating Scales (RRS), The Life Events Checklist, and the Children's Depression Inventory (CDI) were completed by 140 adolescents aged 16-18 years.

RESULTS

Alienation from parents and peers, helpless attributional style, gender, and perceived criticism from teachers contributed significantly to variance in scores for depressive symptoms. Negative self-inference and helpless attributions moderated the relationship between perceived criticism and depression in male participants.

CONCLUSIONS

Different approaches to intervention may be more successful for males and females.

Predictive value of family history on severity of illness: the case for depression, anxiety, alcohol dependence, and drug dependence

CONTEXT

If family history is associated with clinical features that are thought to index seriousness of disorder, this could inform clinicians predicting patients' prognosis and researchers selecting cases for genetic studies. Although tests of associations between family history and clinical features are numerous for depression, such tests are relatively lacking for other disorders.

OBJECTIVE

To test the hypothesis that family history is associated with 4 clinical indexes of disorder (recurrence, impairment, service use, and age at onset) in relation to 4 psychiatric disorders (major depressive episode, anxiety disorder, alcohol dependence, and drug dependence).

DESIGN

Prospective longitudinal cohort study.

SETTING

New Zealand.

PARTICIPANTS

A total of 981 members of the 1972 to 1973 Dunedin Study birth cohort (96% retention).

MAIN OUTCOME MEASURES

For each disorder, family history scores were calculated as the proportion of affected family members from data on 3 generations of the participants' families. Data collected prospectively at the study's repeated assessments (ages 11-32 years) were used to assess recurrence, impairment, and age at onset; data collected by means of a life history calendar at age 32 years were used to assess service use.

RESULTS

Family history was associated with the presence of all 4 disorder types. In addition, family history was associated with a more recurrent course for all 4 disorders (but not significantly for women with depression), worse impairment, and greater service use. Family history was not associated with younger age at onset for any disorder.

CONCLUSIONS

Associations between family history of a disorder and clinical features of that disorder in probands showed consistent direction of effects across depression, anxiety disorder, alcohol dependence, and drug dependence. For these disorder types, family history is useful for determining patients' clinical prognosis and for selecting cases for genetic studies.

Characteristics, correlates, and outcomes of childhood and adolescent depressive disorders

Depressive illness beginning early in life can have serious developmental and functional consequences. Therefore, understanding the disorder during this developmental stage is critical for determining its etiology and course, as well as for deveiopinq effective intervention straieqies. This paper summarizes current knoviedqe reqardinq the etiology, phenomenoiogy, correlates, natural course, and consequences of unipolar depression in children and adolescents. Using adult depression as a framevork, the unique aspects of childhood and adolescence are considered in order to better understand depression within a developmental context. The data suggest that the clinical presentation, correlates, and natural course of depression are remarkably similar across the lifespan. There are, however, important developmental differences. Specifically, the familial and psychological context in which depression develops in youngsters is associated with variability in the frequency and nature of depressive symptoms and comorbid conditions among children and adolescents. Maturational differences have also been identified in the neurobiological correlates of depression. These developmental differences may be associated with the observed variability in clinical response to treatment and longitudinal course. Characterization of the developmental differences will be helpful in developing more specific and effective interventions for youngsters, thereby allowing them to reach their full potential as adults.

The genetics of depression in childhood and adolescence

This article reviews family, twin, and adoption studies of childhood and adolescent depression. Results from several family and twin studies suggest that an etiologic heterogeneity exists in depression in childhood and adolescence. Twin studies show that genetic influences on depression in young people may be indirect and work via effects on environmental risk exposure (gene-environment correlation) or genetic sensitivity to environmental risks (gene-environment interaction). Recent research on gene-environment interaction has examined the effect of specific functional genetic polymorphisms in conjunction with environmental stressors. Future research needs to work toward identifying which environmental and genetic risk factors are crucial to the development of depression in youth, as well as mechanisms involved in the familial transmission of depression. This will not only improve understanding of the etiology of childhood and adolescent depression but also inform the development of therapeutic and preventive interventions.

Familiality of depression in the community; associations with gender and phenotype of major depressive disorder

INTRODUCTION

Although associations between family history and depression have been shown in clinical patients, it is unknown if they also apply to subjects living in the community. The present study considers the relationship between family loading and depression phenotype characteristics in a large community-based sample.

METHOD

In a Dutch representative population sample of 7,076 individuals, lifetime diagnosis of depression was classified according to severity, course and age of onset. A family loading score of depression (FLSD) was computed by taking the proportion of the first-degree relatives for whom a history of depression was reported.

RESULTS

There was a strong association between FLSD and lifetime diagnosis of MDD. Severity, recurrence and early onset of depression were the specific phenotypic characteristics associated with familiality. The effects of FLSD and gender were independent.

CONCLUSION

Associations between family history and risk for depression in the community confirm those reported from clinical-based studies using direct interviewing of relatives. A stronger degree of familiality is associated with specific phenotypic characteristics of depression.

Family-based interpersonal psychotherapy for depressed preadolescents: an open-treatment trial

AIM

To conduct an open-treatment trial to evaluate the feasibility, acceptability and clinical outcomes of using a family-based adaptation of Interpersonal Psychotherapy for Depressed Adolescents with a sample of preadolescents (ages 9-12) presenting for outpatient treatment for depression.

METHODS

Sixteen preadolescents who met criteria for a depressive disorder according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition participated in this open-treatment trial of family-based interpersonal psychotherapy (FB-IPT). Parents chose whether their preadolescents should receive FB-IPT only (n = 10) or FB-IPT with antidepressant medication (n = 6). Pre- and post-treatment assessments included clinician-administered measures of depression and global functioning, and parent- and child-reported anxiety symptoms.

RESULTS

FB-IPT was associated with high treatment compliance rates (88%) and was associated with significant decreases in preadolescents' depressive and anxiety symptoms. Preadolescents who received FB-IPT only were as likely as those receiving FB-IPT and medication to have significant reductions in depressive symptoms and anxiety symptoms, and to experience significant improvement in global functioning. Parents were more likely to choose combination treatment when their depressed preadolescents had a comorbid anxiety disorder.

CONCLUSIONS

Further research on FB-IPT is needed to establish its efficacy as compared with usual outpatient treatment, its ability to be disseminated to child clinicians with varying levels of training and in adequately powered randomized controlled trials that can detect group differences.

Familiality of major depressive disorder and gender differences in comorbidity

OBJECTIVE

Gender differences exist in the prevalence and psychiatric comorbidity of major depressive disorder (MDD). This study investigates whether familiality of MDD contributes to observed gender differences in comorbidity.

METHOD

Familial (f-MDD) and non-familial (nf-MDD) MDD cases from a population sample were assessed for comorbid dysthymia, anxiety disorders and alcohol-related disorders using the Composite International Diagnostic Interview (CIDI). Logistic regression analyses were performed to examine the effect of f-MDD on gender differences in comorbidity, adjusted for confounders.

RESULTS

Women with f-MDD reported significantly more comorbid dysthymia and generalized anxiety disorder (GAD) than their male counterparts; women with nf-MDD reported significantly more comorbid simple phobias and agoraphobia than their male counterparts. Gender differences in comorbid panic disorder and alcohol-related disorders occurred independently of the familial load. Adjustment for age of onset, severity and recurrence of MDD did not change these results.

CONCLUSION

Models to explain comorbidity patterns of MDD differ by gender. Familiality of MDD should be taken into account.

Links between depression and substance abuse in adolescents: neurobiological mechanisms

Adolescence is a high-risk period for development of both depressive and substance use disorders. These two disorders frequently co-occur in adolescents and are associated with significant morbidity and mortality. Given the added economic and psychosocial burden associated with the comorbid condition, identification of risk factors associated with their co-occurrence is of great public health importance. Research with adult animals and humans has indicated several common neurobiological systems that link depressive and addictive disorders. Given the ongoing maturation of these systems throughout adolescence and early adult life, it is not clear how these neurobiological processes influence development and progression of both disorders. A better understanding of the pathophysiological mechanisms leading to the onset and course of these disorders during adolescence will be helpful in developing more effective preventive and treatment strategies, and thereby allow these youth to reach their full potential as adults.

Implications of high-risk family studies for prevention of depression

The high-risk family study is a powerful design that facilitates identification of early forms of expression of depression and premorbid vulnerability, risk, and protective factors that are important for defining prevention targets and program foci. This paper (1) highlights the strengths of high-risk studies for informing early intervention efforts; (2) summarizes findings of familial aggregation from controlled high-risk studies of depression; and (3) briefly reviews evidence for potential mediators (i.e., early forms of expression, vulnerability factors) that explain familial risk and for moderators (i.e., interactive risk and protective factors) that enhance or minimize familial risk. New data from the Yale High-Risk Study of Comorbidity of Substance Use and Affective Disorders are presented to exemplify strategies for identifying specific familial pathways to depression among offspring of parents with substance and anxiety disorders. Likewise, parental depression is associated with a range of emotional and behavioral problems, including anxiety and conduct disorder, in their offspring. These nonspecific effects, together with emerging findings on mechanisms of risk, support early intervention efforts that target a range of youth at risk for depression through multipronged approaches that attend to the individual characteristics of the child and parent, clinical comorbidity, and the broader family and social context.

Depressive disorders in childhood and adolescence: an overview: epidemiology, clinical manifestation and risk factors

The diagnostic category of depressive disorder in pediatric age is a relatively new concept that is rooted in empirical studies that date back to only the late 1980s. This article discusses the current consensus nosology and epidemiology of unipolar depressive disorders in young age and the risk factors for depression onset and recurrence. There is also a brief overview of psychosocial and pharmacologic evidence-based therapies and suggested areas for future research. This article also contains a brief description of the items discussed in detail in this issue.

Neurobiology of depression in children and adolescents

This article reviews classical and updated studies of the neurobiology of depressive disorders in children and adolescents. Most studies of childhood and adolescent depression and suicide have followed up the observations and methods used in studies in adults. These studies include neuroendocrine studies, which particularly look at the hypothalamic-pituitary-adrenal axis, the serotonergic system, peripheral blood and cerebrospinal fluid biologic markers, genetics, gene-environment interactions and sleep studies, and neuroimaging and postmortem studies, although in these areas the number of studies is limited.

Predictors and correlates of high levels of depression and anxiety symptoms among children at age 10

OBJECTIVE

To identify factors that predict or are correlated with symptoms of depression and anxiety in 10-year-olds.

METHOD

Women and their offspring were followed from the fourth prenatal month through 10 years. There were 636 mother-child pairs at 10 years, a follow-up rate of 83% of the birth cohort. Cognitive, psychological, sociodemographic, and environmental factors were measured at each phase. High depression and anxiety were defined as having a number of symptoms >1 SD above the mean for each measure. These measures were combined to represent high depression and/or anxiety (D/A) at 10 years of age.

RESULTS

Predictors from the prenatal period of D/A at 10 years were more maternal depression symptoms, African American race, less social support, greater household density, and prenatal marijuana exposure. From 18 months through 6 years, lower child IQ, child injuries at age 3, and attention problems predicted symptoms of D/A at age 10. Across all study phases, lower child IQ, household density during pregnancy, attention problems, early childhood injuries, and prenatal marijuana exposure predicted D/A. Maternal psychological and sociodemographic factors were not significant in the final model.

CONCLUSIONS

Factors from gestation and early childhood predict high symptom levels of depression and anxiety at age 10. When gestational exposure, early environmental factors, and child characteristics were considered, maternal depression and socioeconomic status were not significantly associated with early onset D/A. Marijuana exposure during gestation marginally predicted depression/anxiety at age 10.

Association of parental depression with psychiatric course from adolescence to young adulthood among formerly depressed individuals

The authors examined whether parental major depressive disorder (MDD) is associated with course of depression and other psychopathology among formerly depressed adolescents as they enter adulthood. The sample consisted of 244 individuals (age 24) in a longitudinal study who had experienced MDD by 19. Maternal MDD was associated with MDD recurrence, chronicity and severity, anxiety disorders, and (among sons only) lower psychosocial functioning in offspring between the ages of 19 and 24. Paternal MDD was associated with lower functioning. Sons of depressed fathers had elevated suicidal ideation and attempt rates in young adulthood. Recurrent paternal MDD was associated with depression recurrence in daughters but not sons. The impact of parental MDD on offspring could not be attributed to characteristics of the offspring's depression prior to age 19.

Age and gender differences in depressive symptomatology and comorbidity: an incident sample of psychiatrically admitted children

BACKGROUND

Studies indicate that major depressive disorder (MDD) is frequent in children but that it may be missed. This study determines the incidence of hospital-treated MDD based on the frequency of MDD in child psychiatric patients, and analyses effects of age and gender on depressive symptoms and psychiatric comorbidity.

METHODS

One hundred ninety-nine consecutive child psychiatric patients were interviewed using a semi-structured diagnostic interview (K-SADS-PL). Comorbidity and symptoms were compared across age and gender.

RESULTS

Current or partly remitted MDD was found in 42 children (21%). Thirty-eight (90%) had comorbid psychiatric disorder(s). Onset of the comorbid disorder was prior to onset of depression in 74% of cases. No significant gender-differences were found, but anhedonia, hypersomnia and decreased ability to concentrate were more frequent in the older age group. In contrast, feelings of worthlessness were more frequent in the younger age group. The number of melancholic symptoms was significantly associated with older age.

CONCLUSION

MDD is frequent in child psychiatric patients aged 8-13 years. Age-but not gender-had significant effects on melancholy score and the prevalence of specific symptoms. Results suggest that MDD may be underdiagnosed in clinical samples unless careful examined with diagnostic interview.

The epidemiology of mood disorders

This review provides an overview of the epidemiology, risk factors, and genetic epidemiology of mood disorders in adults and children. The magnitude and impact of mood disorders in the community outweighs that of most other chronic diseases. Although there is substantial knowledge regarding the sociodemographic risk factors for mood disorders, our understanding of the pathogenesis and classification still is evolving. Comorbidity of mood disorders with anxiety disorders and substance abuse has been documented widely. Whereas substance abuse and mood disorders seem to be independent etiologically, anxiety and mood disorders result from partially common etiologic factors. The results of family, twin, and adoption studies reveal that a positive family history is the most potent risk factor for mood disorders, particularly bipolar disorder. However, the specific factors that are transmitted in families still are unknown. The two areas that will inform future genetic research include phenomenologic studies that refine the validity of the current phenotypic classification of mood disorders, and application of study designs to elucidate specific factors that may explain the familial transmission of these disorders.

Leitlinien zur Diagnostik und Psychotherapie von depressiven Störungen im Kindes- und Jugendalter: Ein evidenzbasierter Diskussionsvorschlag

Zusammenfassung. Ein Entwurf evidenzbasierter Leitlinien zur Diagnostik und Psychotherapie von depressiven Störungen im Kindes- und Jugendalter wird vorgestellt. Für die Diagnosestellung depressiver Störungen im Kindes- und Jugendalter müssen die gleichen diagnostischen Kriterien nach ICD-10 erfüllt sein wie für Erwachsene. Allerdings kann das klinische Bild einer Depression in verschiedenen Altersgruppen deutlich variieren. Depressive Störungen sind vor allem im Jugendalter häufig, chronische Verläufe und Rückfälle treten auf und sie gehen oft mit komorbiden Störungen wie Angststörungen, Störungen des Sozialverhaltens und Störungen durch Substanzgebrauch einher. Wirksame Interventionsansätze zur Prävention depressiver Störungen und zur Akutbehandlung bei leichten und mittelschweren depressiven Störungen stehen zur Verfügung. Die psychotherapeutischen Interventionen der Wahl stellen derzeit kognitiv-verhaltenstherapeutische Ansätze (KVT) und die interpersonale Therapie (IPT) dar. Die Antidepressiva der Wahl sind derzeit selektive Serotoninwiederaufnahmehemmer (SSRI). Weitere Studien, vor allem hinsichtlich Rückfallprophylaxe und der Evaluation der Wirksamkeit einer Kombinationsbehandlung von Psychotherapie mit antidepressiver Medikation stehen noch aus.

Early-onset depression and the emotional and behavioral characteristics of offspring

We compared the emotional and behavioral characteristics of offspring of parents with early-onset depression and the offspring of parents with late-onset depression. Forty-three parents who met criteria for major depressive disorder (MDD) completed the Achenbach Child Behavior Checklist-Parent Report Version (CBCL) for a birth child (n=43, age range 6-17 years). Parents were classified as having either early SD onset (<19 years) or late-onset (> or = 19 years) MDD based on responses gathered during the SCID-P interview. Unpaired t-tests were used to compare the two offspring groups on CBCL clinical and competency scales. Chi-square analyses and unpaired t-tests were used to compare the two parent groups on demographic and clinical features. Offspring of parents with early-onset depression scored significantly higher on the majority of the CBCL clinical scale scores when compared with offspring of parents with late-onset depression, rated as exhibiting higher levels of the characteristics measured: withdrawn, anxious/depressed, social problems, thought problems, attention problems, delinquent behavior, and aggressive behavior. Additionally, this group had a significantly higher total T score (a global measure of psychopathology) and significantly lower social functioning. Children of parents with early-onset depression may be at higher risk for behavioral and emotional problems than offspring of parents with late-onset depression. This finding may be significant in uncovering sources of vulnerability and formulating intervention strategies for offspring of depressed parents.

Clinical presentation and course of depression in youth: does onset in childhood differ from onset in adolescence?

OBJECTIVE

To simultaneously and prospectively compare the clinical presentation, course, and parental psychiatric history between children and adolescents with major depressive disorder.

METHOD

A group of prepubertal children (n = 46) and postpubertal adolescents (n = 22) were assessed with structured interviews for psychopathology and parental psychiatric history and followed once every 2 years for approximately 5 years.

RESULTS

With the exception of more depressive melancholic symptoms in the adolescents, both groups had similar depressive symptomatology, duration (average 17 months), severity of the index episode, rates of recovery (85%) and recurrence (40%), comorbid disorders, and parental psychiatric history. Female sex, increased guilt, prior episodes of depression, and parental psychopathology were associated with worse longitudinal course.

CONCLUSIONS

In general, major depressive disorder is manifested similarly in children and adolescents, and both groups have a protracted clinical course and high family loading for psychiatric disorders.

Depression and bipolar support alliance consensus statement on the unmet needs in diagnosis and treatment of mood disorders in children and adolescents

OBJECTIVE

To focus attention on the critical unmet needs of children and adolescents with mood disorders and to make recommendations for future research and allocation of healthcare resources.

METHOD

The 36-member Consensus Development Panel consisted of experts in child/adolescent or adult psychiatry and psychology, pediatrics, and mental health advocacy. Reviews of the literature concerning youth mood disorders were performed on the subjects of risk factors, prevention, diagnosis, treatment, and services delivery, and opinions and experiences of mental health advocates were obtained.

RESULTS

The Consensus Development Panel listened to presentations and participated in discussions. Independent workgroups of clinicians, scientists, and mental health advocates considered the evidence and prepared preliminary statements. Workgroup leaders presented drafts for discussion by the Consensus Development Panel. The final document was reviewed by the entire group and edited to incorporate input from all participants.

CONCLUSIONS

Evidence suggests high rates of unmet needs for children and adolescents with depression or bipolar disorder. Training is largely limited to child mental health specialists; general psychiatrists, pediatricians, and other primary care physicians receive little or no training. As a result, treatment patterns may reflect adult treatment plans that are not validated for youths. Effective treatments have been identified and some preliminary prevention models have been developed, but they are not yet widely applied. Patients experience limited exposure to clinicians adequately trained to address their problems and little information to guide care decisions, particularly concerning bipolar disorder. National efforts are required to restructure healthcare delivery and provider training and to immediately develop more advanced research on pathophysiology, prevention, and services delivery effectiveness.

Assessing the effects of age, sex and shared environment on the genetic aetiology of depression in childhood and adolescence

BACKGROUND

Depressive symptoms and disorder are experienced by a significant proportion of young people and have long-lasting deleterious effects. The aims of the current investigation were to examine the aetiology of depressive symptoms using a twin design. In particular to examine the effects of sex, age, maternal depression and anxiety symptoms and to examine the aetiology of high depression scores.

METHODS

Questionnaires were sent to the families of a population-based sample of twins aged between 8 and 17 years. Parents and children over the age of 11 were asked to complete the Mood and Feelings Questionnaire and Hospital Anxiety and Depression Scale (mothers only). Responses were obtained from 1463 families and data were analysed using genetic model fitting and DeFries and Fulker regression analysis.

RESULTS

Depressive symptoms, particularly when self-rated, were significantly genetically influenced. There was evidence of significant heterogeneity according to age, with shared environmental factors more important and genetic factors less important for children aged 8 to 10 than for adolescents aged 11 to 17 years. Some but not all of the shared environmental influences on parent-rated depressive symptoms were accounted for by maternal symptoms of depression and anxiety. There was a significant effect of gender for self-rated depressive symptoms. For boys, genetic factors were of greater importance and common environmental influences of less importance than for girls. Shared environmental effects had a substantial influence on high self-rated depression scores. Adolescents who scored highly on self-rated depression questionnaires experienced significantly more shared life events and their mothers had significantly higher internalising symptoms than adolescents who scoredwithin the normal range.

CONCLUSIONS

The results of this study add to the evidence that the aetiology of depressive symptoms differs by age, with genetic factors becoming more important from childhood to adolescence. Some but not all of the shared environmental effect observed for mother-rated depression scores is due to maternal depression and anxiety symptoms. For self-rated depressive symptoms, the importance of genetic and environmental factors may also differ by sex, with genetic influences more important for boys. The aetiology of high depression symptom scores, when self-rated, appears to differ from scores within the normal range in that shared environmental factors appear to be more important. Further research is needed to identify these shared environmental factors using longitudinal models that test genetic and environmental mediation.

Future of genetics of mood disorders research

This report summarizes the deliberations of a panel with representation from diverse disciplines of relevance to the genetics of mood disorders. The major charge to the panel was to develop a strategic plan to employ the tools of genetics to advance the understanding, treatment, and outcomes for mood disorders. A comprehensive review of the evidence for the role of genetic factors in the etiology of mood disorders was conducted, and the chief impediments for progress in gene identification were identified. The National Institute of Mental Health (NIMH) portfolios in the Genetics Research Branch and the Division of Mental Disorders, Behavioral Sciences, AIDS, and all genetics training activities were reviewed. Despite some promising leads, there are still no confirmed linkage findings for mood disorders. Impediments to gene finding include the lack of phenotypic validity, variation in ascertainment sources and methodology across studies, and genetic complexity. With respect to linkage, the committee recommended that a large-scale, integrated effort be undertaken to examine existing data from linkage and association studies of bipolar disorders using identical phenotypes and statistical methods across studies to determine whether the suggestive linkage findings at some loci can be confirmed. Confirmation would justify more intensive approaches to gene finding. The committee recommended that the NIMH support continued efforts to identify the most heritable subtypes and endophenotypes of major depression using the tools of genetic epidemiology, neuroscience, and behavioral science. The field of genetic epidemiology was identified as an important future direction because population-based, epidemiologic studies of families and unrelated affected individuals assume increasing importance for common chronic diseases. To prepare for shifts to more complex genetic models, the committee recommended that the NIMH develop new interdisciplinary training strategies to prepare for the next generation of genetics research.

Parental depression and depression in offspring: evidence for familial characteristics and subtypes?

The objectives of this paper were twofold. First, to evaluate in a community sample the age of onset of major depression in adolescents and young adults with and without parental major depression. Second, to examine whether specific clinical characteristics of major depression in adolescents and young adults are associated with elevated rates of major depression among parents. Baseline and 4-year follow-up data were used from the Early Developmental Stages of Psychopathology Study (EDSP), a prospective-longitudinal community study of adolescents and young adults. Results are based on 470 subjects who completed the follow-up, for whom diagnostic information for both parents was available, and who reported at least one episode of major depression according to DSM-IV-criteria through second follow-up. Diagnostic assessment in respondents was accomplished by using the standardized Munich-Composite International Diagnostic Interview (M-CIDI). Information on major depression in parents was collected as family history information from the respondents, and additionally from M-CIDI diagnostic interviews with parents of the younger cohort. Both recurrence and impairment as clinical characteristics of major depression in adolescents and young adults were associated with elevated rates of major depression among parents. Age of onset as well as overall higher impairment as clinical characteristics of major depression in youth were associated with elevated rates of parental major depression in the univariate, but not in the multiple, analyses. Our findings suggest that clinical features of major depression may indicate familial subtypes of the disorder, most evident for recurrence and impairment.

Adult religiousness and history of childhood depression: eleven-year follow-up study

This study investigates the association between childhood depression and the protective qualities of adult religiousness. Subjects were 146 (65 female and 81 male) adults with a history of childhood depression and 123 (61 female and 62 male) adults without a history of childhood depression interviewed as part of a long-term follow-up study (mean years of follow-up, 11.2; SD = 1.4). Depression in childhood and adulthood was assessed by blind and independent clinical interviews by using the Schedule for Affective Disorders for School Aged Children and the Schedule for Affective Disorders Life-time Version, respectively. Religiousness was assessed by report on the personal importance of religion, frequency of attendance of religious services, religious denomination, and child-adult concordance of report. Findings showed adult personal importance of religion to be associated with a decreased risk for depression in women without a history of childhood depression but an increased risk for depression in women with a history of childhood depression. Adult Catholicism as compared with Protestantism was associated with a decreased risk for depression in male childhood depressives, but this association was not found in men without childhood depression. The findings potentially suggest a reciprocal-influence process between childhood pathology and the development of religiousness.

Pediatric bipolar mood disorder

The diagnosis of bipolar mood disorder (BP) in preadolescents (pediatric mania) has generated considerable controversy in terms of its estimated prevalence and validity as a diagnostic category. The relative paucity of systematic studies and the current diagnostic confusion related to the disorder are often attributed to the apparent discontinuities in the childhood versus adult presentation of the illness, namely, irritability as the predominant "mood" of mania and a continuous course of symptoms. The goal of this article is to review the current literature and identify sources of confusion relating to pediatric mania by considering results to date within a larger context that include findings from studies on (1) BP illness in adults, (2) mood disorders across the lifespan, (3) the role of development in symptom expression, and (4) patterns of heritability in psychiatric disorders. Whereas much remains to be investigated in the validation of the diagnosis for children, integrating results across studies may provide a framework for understanding the differences in the presentation of severe mood disorders in children and adults.

A developmental psychopathology perspective on adolescence

Developmental psychopathology offers an integrative framework for conceptualizing the course of development during adolescence, with particular relevance for understanding continuity and the emergence of psychopathology during this and subsequent developmental periods. In this article, the utility of a developmental psychopathology perspective for informing the design of research, prevention, and intervention is highlighted. Interdisciplinary, organizational models of development, emphasizing the dynamic relations between the developing individual and internal and external contexts, are discussed. Examination of boundaries between abnormal and normal development during adolescence offers important vantage points for articulating diversity in the developmental course during this period. Conceptualizing divergence and convergence in developmental pathways, continuity and discontinuity in development, and the transactions of risk and protective processes leading to maladaptation, psychopathology, and resilience are highlighted.

Relation between anxiety and depressive disorders in childhood and adolescence

Current research indicates that there is a strong relationship between pediatric anxiety disorders and depression. Assessment measures show high rates of correlation between depression and anxiety and much of the overlap may be related to a common domain of negative affectivity. Anxious youth and depressed youth share a cognitive style marked by a negative bias in information processing. Anxiety disorders and depression are frequently comorbid in children and adolescents. About 25-50% of depressed youth have comorbid anxiety disorders and about 10-15% of anxious youth have depression. Twin and family studies have demonstrated that pediatric anxiety disorders and depression likely share some common genetic factors or influences. Selective serotonin reuptake inhibitors and cognitive-behavioral therapy have been shown in randomized controlled trials to be efficacious for both pediatric depression and anxiety disorders. Integrating the treatment literature with studies of phenomenology, biology and genetics indicates that pediatric anxiety disorders and depression may share a genetically determined neurobiological component that could involve neural circuits that include or are modulated by serotonergic neurons. This component could contribute to the negative affective temperament that appears to be common in both pediatric depression and anxiety disorders.

The genetic aetiology of childhood depression: a review

BACKGROUND

We review the evidence for the familiality of major depressive disorder (MDD) and the genetic aetiology of depressive symptoms in children and adolescents.

METHODS

Databases and reference lists were searched for family, twin and adoption studies of childhood MDD and childhood depressive symptoms. Data from independent family studies that fulfilled specified inclusion criteria were pooled and odds ratios were calculated for top-down and bottom-up family studies.

RESULTS

Estimates of familial risk differ by control group and by study design (odds ratio range 1.70, 3.98). Twin studies show that depressive symptoms in young people are heritable although rater and measurement issues are important. Adoption studies show little evidence for a genetic influence on depressive symptoms.

CONCLUSIONS

MDD in young people is familial although control group and study design affect the magnitude of the familial risk. Estimates of heritability from twin and adoption studies vary widely and few firm conclusions can be made regarding the genetic aetiology of depressive symptoms in childhood. Areas that require future work include the examination of rater effects, measurement issues, the effects of age and comorbidity and reasons for the discrepancy between twin and adoption findings.