Psychiatric disorders in the relatives of probands with prepubertal-onset or adolescent-onset major depression

Pursuing the epidemiology and familial risks of depression and developing an evidence based psychotherapy

This commentary, as requested, presents the highlights of my research career. The epidemiology of psychiatric disorders study, challenged in a small study, the notion that diagnosis for psychiatric disorders could be made in a community survey. This pilot study was the basis for the Epidemiology Catchment Area Study (ECA) with 18,000 participants and the many more updated surveys, which followed. The families at High and Low Risk for Depression study in its 40th year challenged the notion that children didn't get depressed and showed that parental depression was the major risk for depression, which began in youth and reoccurred over the lifespan. Interpersonal psychotherapy (IPT), now has been tested in over 150 clinical trials, recommended by the World Health Organization (WHO), globally in China, Germany, Ukraine, and many more countries.

Contributing factors to heterogeneity in the timing of the onset of major depressive episode: Results from a national study

INTRODUCTION

It remains unclear whether specific clinical factors contribute to heterogeneity in the timing of the onset of major depression.

METHODS

Using a nationally representative US adult sample, the second wave of the National Epidemiologic Survey on Alcohol and Related Conditions, we compared the characteristics of 5 different groups of patients defined by their age at onset: (i) before 18 years, (ii) between 18 and 34 years, (iii) between 35 and 44 years, (iv) between 45 and 59 years, and (v) 60 years or older. Specifically, we examined parental history of psychiatric disorders, history of childhood maltreatment experiences, sociodemographic characteristics, lifetime psychiatric disorders, and psychiatric disorders that occurred before the first major depressive episode (MDE).

RESULTS

Compared with first MDE occurring between 18 and 34 years, first MDE before 18 years was more strongly associated with childhood maltreatment and family history of psychiatric disorders, and less strongly linked to prior lifetime psychiatric disorders, whereas first MDE occurring at 60 years and older was more strongly associated with widowhood and a prior lifetime history of generalized anxiety disorder.

LIMITATIONS

Associations found cannot be interpzreted as causal relationships due to study design and the risk of recall bias.

CONCLUSION

Our results suggest substantial age differences in risk factors for first MDE. Improving early detection and treatment of major depression and other psychiatric disorders, and preventing childhood maltreatment may have broad benefits to reduce the burden of MDE at all ages.

Associations of Childhood and Adolescent Depression With Adult Psychiatric and Functional Outcomes

OBJECTIVE

Depression is common, impairing, and the leading cause of disease burden in youths. This study aimed to identify the effects of childhood/adolescent depression on a broad range of longer-term outcomes.

METHOD

The analysis is based on the prospective, representative Great Smoky Mountains Study of 1,420 participants. Participants were assessed with the structured Child and Adolescent Psychiatric Assessment interview up to 8 times in childhood (age 9-16 years; 6,674 observations; 1993-2000) for DSM-based depressive disorders, associated psychiatric comorbidities, and childhood adversities. Participants were followed up 4 times in adulthood (ages 19, 21, 25, and 30 years; 4,556 observations of 1,336 participants; 1999-2015) with the structured Young Adult Psychiatric Assessment Interview for psychiatric outcomes and functional outcomes.

RESULTS

In all, 7.7% of participants met criteria for a depressive disorder in childhood/adolescence. Any childhood/adolescent depression was associated with higher levels of adult anxiety and illicit drug disorders and also with worse health, criminal, and social functioning; these associations persisted when childhood psychiatric comorbidities and adversities were accounted for. No sex-specific patterns were identified. However, timing of depression mattered: individuals with adolescent-onset depression had worse outcomes than those with child-onset. Average depressive symptoms throughout childhood and adolescence were associated with more adverse outcomes. Finally, specialty mental health service use was protective against adult diagnostic outcomes.

CONCLUSION

Early depression and especially persistent childhood/adolescent depressive symptoms have robust, lasting associations with adult functioning. Some of these effects may be attenuated by service use.

Editorial: What are the "Doses," Timing, and Treatment of Childhood Depression That Impact Adulthood?

Depression creates more burden globally than nearly any other physical or mental disorder, yet surprisingly, little is known about what can be done to prevent its onset and, as Duarte et al.,¹ in this issue of JAACAP, address, what the long-term outcomes of youth depression are. The existing medical literature on outcomes of child and adolescent depression is large enough for 2 recent reviews,^2,3 which point out the key gaps in our understanding. Does childhood depression actually worsen adult outcomes, or is the driver really all the associated childhood adversity and comorbidity? Although we know women suffer disproportionately from depression, are childhood predictors specific to girls or boys? Is it worse to have many episodes of depression in one's youth than a few? Do subthreshold depressive symptoms impact adulthood too? Finally, is it important, in adulthood, whether depression began in childhood or adolescence?

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.

Maternal Prenatal Stress and Other Developmental Risk Factors for Adolescent Depression: Spotlight on Sex Differences

Maternal stress during pregnancy has been linked to premorbid abnormalities associated with depression (e.g., difficult temperament, cognitive deficits) in offspring. However, few studies have looked across developmental periods to examine maternal stress during pregnancy and offspring depression during adolescence and whether these associations differ by sex. The current study used data from 1711 mother-offspring dyads (offspring sex: 49.8% male) in a longitudinal birth cohort study. Maternal narratives collected during pregnancy were qualitatively coded for stress-related themes by independent raters. Latent class analysis (LCA) identified distinct subgroups of offspring based on exposure to maternal prenatal stress and other developmental factors from the prenatal, childhood, and adolescent periods that have been associated with depression and/or maternal prenatal stress. LCA identified subgroups that were compared to determine whether and to what extent they differed on adolescent depressive symptoms. LCA revealed a subgroup of "high-risk" individuals, characterized by maternal factors during pregnancy (higher ambivalence/negativity and lower positivity towards the pregnancy, higher levels of hassles, lower maternal education and higher maternal age at birth, higher pre-pregnancy BMI) and offspring developmental factors (decreased cognitive functioning during childhood and adolescence, lower perceived parental support during adolescence, and higher levels of maternal depression during adolescence). High-risk females exhibited elevated conduct symptoms and higher birth order, while high-risk males exhibited decreased internalizing symptoms and lower birth order. Both high-risk males and females reported elevated depressive symptoms during adolescence relative to their "low-risk" counterparts.

Neonatal lipopolysaccharide treatment alters hippocampal neuroinflammation, microglia morphology and anxiety-like behavior in rats selectively bred for an infantile trait

Disruptions in homeostasis, such as the induction of inflammation, occurring during the neonatal period of development often produce changes in the brain, physiology, and behavior that persist through the life span. This study investigated the potential effects that an immune challenge delivered during neonatal development would have on anxiety behavior and stress reactivity later in life within a selectively-bred strain of rat. The rats have been bred for multiple generations to display either high or low anxiety-like phenotypic behavior. On postnatal day (P)3 and P5, male and female neonates were injected with saline or lipopolysaccharide (LPS). Brains were collected from a subset of neonates following injections. At P7, one male and one female per litter were tested for ultrasonic vocalizations (USVs). In adulthood, remaining litter mates were tested on the open field apparatus and the elevated zero maze (EZM) or on the EZM following 3days of acute stress. Overall, we saw differences between the High and Low lines in neonatal anxiety-like behavior (USVs), neonatal peripheral immune response, adult anxiety-like behavior on the EZM, and adult anxiety-like behavior after stress induction, such that the High line rats display significantly more anxiety-like behavior than the Low line. Furthermore, we observed an effect of neonatal LPS during the neonatal peripheral immune response (e.g., increased inflammatory cytokine expression) and adult anxiety-like behavior on the EZM. We also observed an effect of sex within the anxiety-like behavior of LPS-treated adults exposed to stress paradigm. The combined results shed light on the relationships between neural development, early-life inflammation and anxiety throughout the lifespan.

The Next Big Thing in Child and Adolescent Psychiatry: Interventions to Prevent and Intervene Early in Psychiatric Illnesses

The last two decades have marked tremendous progress in our ability to prevent and intervene early in psychiatric illnesses. The interventions described in this article range from established, empirically-supported treatments to creative interventions early in their development and deployment. Some of these interventions are low-technology programs delivered in social settings (such as schools), and some rely on sophisticated emerging technologies such as neuroimaging. This article reviews 4 preventative interventions: 1) The use of structural brain imaging to identify children at risk for familial depression who are most likely to benefit from preventative cognitive behavioral therapy 2) The Good Behavior Game, a school based program that, when implemented in 1st grade classrooms, cut the incidence of substance use disorders in students in half when those students were 19 years old, 3) The SPARX video game, which has the potential to be an accessible, appealing, and cost-effective treatment for the thousands of teens affected by mild to moderate depressive disorders, and 4) Intensive psychosocial treatments which can reduce the progression of from the ultra high risk state to the first episode psychosis by 50% over 12 months. All of these interventions have tremendous potential to reduce the suffering and disability caused by psychiatric illness to both children and adults.

Inter-informant agreement and prevalence estimates for mood syndromes: direct interview vs. family history method

BACKGROUND

The use of the family history method is recommended in family studies as a type of proxy interview of non-participating relatives. However, using different sources of information can result in bias as direct interviews may provide a higher likelihood of assigning diagnoses than family history reports. The aims of the present study were to: (1) compare diagnoses for threshold and subthreshold mood syndromes from interviews to those relying on information from relatives; (2) test the appropriateness of lowering the diagnostic threshold and combining multiple reports from the family history method to obtain comparable prevalence estimates to the interviews; (3) identify factors that influence the likelihood of agreement and reporting of disorders by informants.

METHODS

Within a family study, 1621 informant-index subject pairs were identified. DSM-5 diagnoses from direct interviews of index subjects were compared to those derived from family history information provided by their first-degree relatives.

RESULTS

(1) Inter-informant agreement was acceptable for Mania, but low for all other mood syndromes. (2) Except for Mania and subthreshold depression, the family history method provided significantly lower prevalence estimates. The gap improved for all other syndromes after lowering the threshold of the family history method. (3) Individuals who had a history of depression themselves were more likely to report depression in their relatives.

LIMITATIONS

Low proportion of affected individuals for manic syndromes and lack of independence of data.

CONCLUSIONS

The higher likelihood of reporting disorders by affected informants entails the risk of overestimation of the size of familial aggregation of depression.

Discriminating risk and resilience endophenotypes from lifetime illness effects in familial major depressive disorder

IMPORTANCE

The neural systems that confer risk or vulnerability for developing familial depression, and those that protect against or confer resilience to becoming ill, can be disentangled from the effects of prior illness by comparing brain imaging measures in previously ill and never ill persons who have either a high or low familial risk for depression.

OBJECTIVE

To distinguish risk and resilience endophenotypes for major depression from the effects of prior lifetime illness.

DESIGN, SETTING, AND PARTICIPANTS

We used functional magnetic resonance imaging to measure and compare brain function during performance of an attentional, self-regulatory task across a large sample of multigenerational families ascertained specifically to be at either high or low risk for developing major depression. Study procedures were performed in a university setting. A total of 143 community participants were followed up prospectively for more than 20 years in a university setting. The sample was enriched with persons who were at higher or lower familial risk for developing depression based on being biological offspring of either a clinical sample of persons with major depression or a community control sample of persons with no discernible lifetime illness.

MAIN OUTCOMES AND MEASURES

Task-related change in blood oxygen level-dependent functional magnetic resonance imaging signal.

RESULTS

A risk endophenotype included greater activation of cortical attention circuits. A resilience endophenotype included greater activation of the dorsal anterior cingulate cortex. The effects of prior lifetime illness were common to both risk groups and included greater deactivation of default-mode circuits.

CONCLUSIONS AND RELEVANCE

These findings identify neural systems that increase risk for depression, those that protect from illness, and those that endure following illness onset, and they suggest circuits to target for developing novel preventive and therapeutic interventions.

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.

Accumulation of trauma over time and risk for depression in a twin sample

BACKGROUND

Few genetically informative studies have examined the effects of different types of trauma on risk for depression over time. The aim of the present study was to examine the relative contributions over time of assaultive trauma, non-assaultive trauma, and familial effects to risk for depression.

METHOD

Histories of depression and trauma were obtained during structured diagnostic interviews with 5266 (mean age 29.9 years, s.d.=2.4) members of a volunteer Australian twin panel from the general population. Age at first onset of a DSM-IV major depressive episode was the dependent variable. Associations of depression with traumatic events were examined while accounting for the temporal sequence of trauma and depression and familial effects.

RESULTS

Assaultive traumatic events that occurred during childhood had the strongest association with immediate and long-term risk for depression, and outweighed familial effects on childhood-onset depression for most twins. Although men and women endorsed equal rates of assaultive trauma, women reported a greater accumulation of assaultive events at earlier ages than men, whereas men reported a greater accumulation of non-assaultive events at all ages.

CONCLUSIONS

Early exposure to assaultive trauma can influence risk for depression into adulthood. Concordance for early trauma is a significant contributor to the familiality of early-onset 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.

Age-specific familial risks of depression: a nation-wide epidemiological study from Sweden

OBJECTIVE

Familial risks of depression have been assessed in small case-control studies, usually based on reported, but not medically verified, depressions in family members; thus the degree of familial clustering of these diseases remains to be established.

METHODS

The Multigeneration Register, in which all men and women born in Sweden from 1932 onward are registered together with their parents, was linked to hospital admission data. Standardized incidence ratios (SIRs) were calculated as the ratio of the observed to the expected number of cases in men and women with mothers or fathers affected by depression, compared with men and women whose mothers or fathers were not affected by depression.

RESULTS

A total of respectively 60,477 and 79,969 depressions were recorded in offspring and parents. In 6.44% of all families, an offspring and a parent were affected, giving a population-attributable proportion of 4.04% and a familial SIR of 2.68. The parental transmission of depression was similar for both men and women (2.72 and 2.66).

CONCLUSIONS

This study has provided the first data on age-specific familial clustering of depressions, based on medically confirmed records. The risks were so high that hereditary factors were considered to be likely to contribute to depression, possibly modified by environmental factors. Age-specific risk tables would be helpful for clinical counseling.

Social neuroscience of child and adolescent depression

The social neuroscience of child and adolescent depression is inherently multidisciplinary. Depressive disorders beginning early in life can have serious developmental and functional consequences. Psychopathology research has described depression's defining clinical and contextual features, and intervention research has characterized its response to treatment and prevention programs. Neuroendocrine, electrophysiological, and neuroimaging studies have identified core neurobiological aspects of early-onset mood disorders. These areas are reviewed using a developmental social neuroscience perspective for integrating disparate observations. The paper introduces a dynamic adaptive systems framework, and it discusses hedonic capacity, stress sensitivity, ruminative self-focus, and attentional impairments as fundamental components of mood disorders.

Selective breeding for infant rat separation-induced ultrasonic vocalizations: developmental precursors of passive and active coping styles

Human depression and anxiety disorders show inherited biases across generations, as do antisocial disorders characterized by aggression. Each condition is preceded in children by behavioral inhibition or aggressive behavior, respectively, and both are characterized by separation anxiety disorders. In affected families, adults and children exhibit different forms of altered autonomic nervous system regulation and hypothalamic-pituitary-adrenal activity in response to stress. Because it is difficult to determine mechanisms accounting for these associations, animal studies are useful for studying the fundamental relationships between biological and behavioral traits. Pharmacologic and behavioral studies suggest that infant rat ultrasonic vocalizations (USV) are a measure of an early anxiety-like state related to separation anxiety. However, it was not known whether or not early ultrasound emissions in infant rats are markers for genetic risk for anxiety states later in life. To address these questions, we selectively bred two lines of rats based on high and low rates of USV to isolation at postnatal (P) 10 days of age. To our knowledge, ours is the only laboratory that has ever selectively bred on the basis of an infantile trait related to anxiety. The High and Low USV lines show two distinct sets of patterns of behavior, physiology and neurochemistry from infancy through adulthood. As adults High line rats demonstrate "anxious"/"depressed" phenotypes in behavior and autonomic nervous system (ANS) regulation to standard laboratory tests. In Lows, on the other hand, behavior and autonomic regulation are consistent with an "aggressive" phenotype. The High and Low USV lines are the first genetic animal models implicating long-term associations of contrasting "coping styles" with early attachment responses. They thus present a potentially powerful model for examining gene-environment interactions in the development of life-long affective regulation.

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.

Twin studies in pediatric depression

Pediatric depression is an important clinical problem that is known to be familial. Twin studies have been used not only to examine the genetic etiology of depression but also to investigate developmental changes and gender effects, the relationship of depression with anxiety, and increasingly, the interplay of genetic liability with environmental risk factors. There is evidence that pediatric depression symptom scores and clinical depression are genetically influenced, but results from different twin studies have varied. These studies also have demonstrated the important contribution of environmental risk factors. Some of the differences in findings may be caused partly by clinical heterogeneity, developmental differences in etiology (stronger genetic influences for depression symptom scores in adolescence than in childhood), and measurement issues, such as who rates the symptoms.

Childhood predictors of psychiatric disorders among boys: a prospective community-based follow-up study from age 8 years to early adulthood

OBJECTIVE

To study early childhood predictors for early adulthood psychiatric disorders.

METHOD

The sample included 2,712 Finnish boys born in 1981. Information about the 8-year-old boys' problem behavior was obtained from parents, teachers, and children. The 10-15-year follow-up information about psychiatric disorders in early adulthood was based on the national military register between the years 1999 and 2004.

RESULTS

According to the military register, 10.4% of men had a psychiatric disorder. All informant sources, parents, teachers, and the children themselves predicted early adulthood psychiatric disorders. Conduct symptoms at age 8 independently predicted substance abuse, antisocial personality, and psychotic disorders in early adulthood. Self-reported depressive symptoms, poor school performance, and living in a nonintact family had an independent predictive association with antisocial personality and depressive disorders. Parent-reported emotional symptoms and self-reported psychosomatic symptoms independently predicted anxiety disorders. About one third of those who had used services at age 8 had a psychiatric disorder in early adulthood. Among service users, conduct and hyperkinetic symptoms predicted psychiatric disorders in early adulthood.

CONCLUSIONS

Efforts to prevent early adult psychiatric disturbance already present in childhood are emphasized. Active screening to detect children in need of early interventions in childhood to prevent negative development in early adulthood is justified.

Selective breeding for an infant phenotype: rat pup ultrasonic vocalization (USV)

To examine processes underlying generational and developmental influences on anxiety, this laboratory produced two lines of (N:NIH strain) rats, selectively bred on the basis extreme rates of ultrasonic vocalization in 2 minutes of isolation at Postnatal Day 10. The research reviewed in this article focuses on: (1) establishment of the selectively bred lines; (2) defining infant behavioral and physiological phenotypes and (3) determining whether infantile USV phenotypes endure over development. The High and Low lines have diverged widely in their USV rates from each other and from the Random control line, which has maintained N:NIH strain rates overall from generation to generation. Beginning in the 11th generation, High USV pups have shown significantly higher frequencies of defecation and urination during isolation screening than the Low USV and random control line. Both lines show altered autonomic regulation of heart rates (HR) in response to stressors as juveniles and adults. These differences in HR responses in High and Low lines appear to be mediated by changes in the balance of sympathetic versus parasympathetic mechanisms. Other behavioral characteristics of the High line are consistent with an "anxious"/ "depressive" phenotype, such as vocalizations to touch in a novel environment, and performance in the Porsolt Swim, whereas Low line shows few differences in anxiety behavior. Future work will resolve the similarities and differences in the High and Low phenotypes and provide a developmental perspective to the growing body of information about affective regulation in humans and animals provided by selectively bred animal models.

Psychopharmacology of conduct disorder: current progress and future directions

Behavioural manifestations of conduct disorder (CD) among children and adolescents are one of the most common referrals to community psychiatrists. Patients with CD are difficult to treat. The patterns of maladaptive behaviours they exhibit are diverse and can vary as a function of age and gender. Although different pharmacological interventions have been reported as potentially promising options in the treatment of CD, no medication has yet received a formal approval from the licensure authorities, either in the US or Europe. This article reviews efficacy results and associated adverse effects from selected clinical trials that have the strongest outcome evidence for the treatment of CD in children and adolescents. Critical issues in the effectiveness of the evidence-based pharmacotherapy for CD are raised and future directions of the psychopharmacology of CD are examined.

Approaches to familial aggregation: hypothesis testing and estimation when families are selected through parent probands under a variant of single ascertainment

Epidemiologic approaches to testing and estimating familial aggregation of a disease consist of comparing rates of disease in relatives of individuals with the disease (known as case probands) with rates of disease in relatives of individuals without the disease (known as control probands). Gold et al. (J Am Stat Ass 1967;62: 409-420) derived an explicit mathematical model and sampling methods, under which this approach is equivalent to testing the null hypotheses that the disease risk in families is homogenous. A basic assumption of this model is that every family member has the same risk of disease and that disease status is independent among family members, although the disease risk may vary between families. When the disease is suspected of having a genetic component, rather than being purely environmental, this model has been shown to be appropriate for detecting disease aggregation in siblings, when relatives are siblings of probands. This model however is unrealistic for use in nuclear families when the affected status of offspring is not independent of the affected status of parents, and these families are selected through an affected or an unaffected parent, so that a parent is the proband and relatives are offspring of probands. We extend the Gold et al. model to allow for the disease risk in offspring to vary with the affected status of the parent. We assume that families are selected through affected and unaffected parents, under a variation of single ascertainment. Under this study design, we show that the usual test of association between affected status of probands and relatives, performed by comparing sample proportions of affected relatives of affected and unaffected probands, respectively, is no longer equivalent to a test of homogeneity of disease risk in offspring. Instead, it is equivalent to testing that the disease risk in offspring is independent of the number of affected parents. This test reduces to a test of homogeneity if and only if one assumes that the variation in disease risk in offspring, between families, is solely due to the variation in the number of affected parents. As a result, we show that under this study design, the standard chi2 test must be modified in order to obtain a valid test of familial aggregation. In addition the sample proportions of affected relatives of case and control probands, respectively, are shown to provide unbiased estimates of the expected risk of disease in an offspring given an affected/unaffected parent. We apply these results to methods of sample selection and discuss the practical implications of these findings.

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.

Genetic epidemiology of self-reported lifetime DSM-IV major depressive disorder in a population-based twin sample of female adolescents

BACKGROUND

In adults, about 40% of the variance in risk of Major Depressive Disorder (MDD) is due to genetic factors, but little data exist on the heritability of youth MDD. The goal of this study was the genetic analysis of MDD in an epidemiologically and genetically representative sample of adolescent female twins.

METHODS

A sample of 3416 female adolescent twins systematically ascertained from birth records was assessed using a structured telephone interview that included a comprehensive DSM-IV-based section for the diagnostic assessment of MDD. Mean subject age at time of assessment was 15.5 and participation rate exceeded 85%. Genetic modeling was conducted taking into consideration the problem of censoring, i.e., that younger adolescents were not through their period of risk for adolescent onset of MDD.

RESULTS

Lifetime self-reported MDD prevalence ranged from 1% under age 12 to 17.4% at age 19 and older. The genetic variance in risk of MDD was 40.4% (95% confidence interval (CI): 23.9-55.1), with the remaining variance explained by non-shared environmental effects 59.6% (95%CI: 44.9-76.1). Shared environmental effects were not significant. A significant recall bias was observed with older respondents on average reporting later onsets for their first episode of MDD.

CONCLUSIONS

The genetic and environmental contributions to risk of MDD in this representative sample of female adolescent twins are remarkably analogous to findings from adult samples. These results are congruent with a conceptualization of adolescent MDD and adult MDD as having very similar etiologic determinants.

Differentiating depressed adolescent 24 h cortisol secretion in light of their adult clinical outcome

A clinical follow-up study was performed of adolescent major depressives and normal control subjects approximately 10 years after the subjects had undergone serial cortisol measurements over a 24-h period. In light of their young adulthood clinical status, our objective was to ascertain whether there were any premorbid cortisol abnormalities associated with depressive course of illness. In all, 77 young adults who had received a diagnosis of adolescent major depressive disorder, or were determined to be normal volunteers free of psychiatric diagnosis at index period and during follow-up, were studied. When subjects were adolescents, blood samples were collected for cortisol at 20-min intervals during the 24-h period coinciding with the third consecutive night of sleep EEG. The subjects, in young adulthood at the time of follow-up, were reinterviewed regarding longitudinal course of illness, and the original adolescent cortisol data were analyzed in the light of information obtained. Of the subjects who had experienced at least one lifetime major depressive episode during the follow-up period, the subgroup who would go on to make suicide attempts during the follow-up period secreted significantly greater levels of cortisol in the 4, 6, and 12 h prior to sleep onset. Conversely, this same subgroup exhibited reduced cortisol levels 2-4 h following sleep onset. Adolescents who are at risk to make suicide attempts appear to display significant elevations of cortisol prior to sleep onset, a time when the hypothalamic-pituitary-adrenal (HPA) axis is normally most quiescent. Dysregulation of the HPA axis, combined with dysfunction of sleep-onset mechanisms previously reported in this same cohort, might serve as premorbid biological substrates that predict suicide attempts during follow-up.

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.

Depression in adolescence

Major depression is a common mental health disorder in adolescents that predicts a significant risk for recurrence in adulthood. Suicide is the third most frequent cause of deaths in this age group, and depression is a significant risk factor for suicidal ideation and attempts. Risks for depression and suicidal ideation are reviewed, and subtypes of depression are discussed. Difficulties associated with identification of depression and suicidal ideation in adolescents and biologic therapies for adolescent depression are reviewed.

Nocturnal growth hormone secretion studies in adolescents with or without major depression re-examined: integration of adult clinical follow-up data

BACKGROUND

Early sleep is associated with an increased secretion of human growth hormone (GH) through muscarinic inhibition of somatostatin, a GH suppressant. A clinical follow-up was performed approximately 1 decade after depressed and psychiatrically "normal" control adolescents, who were now young adults, had undergone baseline serial GH measurements over a 24-hour period on the third night of sleep polysomnography studies.

METHODS

The study population consisted of 77 young adults who had received a diagnosis of adolescent major depressive disorder and had participated in the adolescent sleep and neuroendocrine studies. Alternatively, the young adult subjects were assessed as normal adolescent control subjects free of any psychiatric diagnosis. Blood samples had been collected for GH every 20 min during the 24-hour period coinciding with the third consecutive night of sleep electroencephalography. Subjects, now in young adulthood, were relocated and blindly reinterviewed using the Schedule for Affective Disorders and Schizophrenia (lifetime version). The original adolescent nocturnal GH data were analyzed in light of the information obtained regarding clinical course into adulthood.

RESULTS

A substantial proportion of the nominally normal control group developed at least one episode of major depression or dysthymia during the follow-up period. "Latent" depressive subjects differed from depression-free control subjects by having exhibited a significantly more rapid increase of adolescent nocturnal GH secretion following sleep onset. Of the subjects who had experienced at least one lifetime major depressive episode during the follow-up, the subgroup who would go on to make suicide attempts secreted significantly greater amounts of GH during the first 4 hours of sleep. Adults with lifetime depression exhibited significantly reduced levels of GH in the 100 min preceding sleep onset during adolescence.

CONCLUSIONS

Assignment of subjects based on longitudinal clinical follow-up into adulthood revealed that the sleep-related GH secretion paradigm has predictive value for future depressive episodes and future suicide attempts. Dysfunction of complex sleep-onset mechanisms may be a premorbid marker of depression and suicidal behavior.