Family, twin, adoption, and molecular genetic studies of juvenile bipolar disorder

Stimulant Treatment and Potential Adverse Outcomes in Pediatric Populations With Bipolar Disorder: A Systematic Review of the Literature

OBJECTIVE

To explore outcomes of stimulant treatment for ADHD in pediatric populations with particular attention to bipolar disorder (BPD).

METHOD

We conducted a literature search of PubMed articles published prior to August 25, 2022 that focused on BPD, mania, and psychosis prior to, or as result of, stimulant treatment. We excluded studies: (1) unrelated to stimulants, (2) general stimulant research, (3) articles older than 40 years, (4) study protocols, or (5) case reports.

RESULTS

A total of 11 articles met all inclusion/exclusion criteria. Some reports found stimulant treatment safe and well-tolerated in children with comorbid BPD and ADHD. Others found evidence of treatment-emergent mania (TEM), discontinuation, and other adverse events with stimulant treatment.

CONCLUSION

Poor outcomes associated with stimulant treatment in pediatric populations with BPD necessitate work to identify patients at risk of serious stimulant-related adverse events. Our results were limited by automated search filters and a pediatric, primarily male sample.

Dissecting genetic cross-talk between ADHD and other neurodevelopmental disorders: Evidence from behavioural, pharmacological and brain imaging investigations

Several epidemiological and genetic studies have provided evidence of an overlap between neurodevelopmental disorders. However, the details of the etiological pathways remain to be elucidated. In this study, we garnered the findings of previous GWAS, conducted with schizophrenia and bipolar disorder. We conducted an exploratory study to examine the association between these SNPs and quantitative clinical/ behavioural/ cognitive/ structural brain parameters, as well as response to treatment with a fixed dose of methylphenidate, in a relatively large sample of children with ADHD. Family-based association tests were conducted with nine tag SNPs with 602 nuclear families. In addition, structural magnetic resonance imaging (sMRI) was conducted in a subset of children with ADHD (n = 76). Of the 9 tag SNPs examined, rs1602565 showed a significant association with ADHD, several dimensional measures and response to treatment. An association was also observed between rs1006737 (CACNA1C) and performance IQ. In addition, significant reductions in cortical thickness measurements were observed with the risk allele in rs1006737. These results provide preliminary evidence for putative shared genetic vulnerability between childhood ADHD and other neurodevelopmental disorders.

Progress in diagnosis and treatment of bipolar disorder among children and adolescents: an international perspective

Bipolar disorder (BPD) is a potentially lifelong condition characterised by extreme changes in mood that may begin in childhood and cause substantial impairment. Over the past decades, BPD has been the focus of increased attention mainly due to controversies surrounding its prevalence, diagnosis and treatment in children and adolescents. This report addresses these controversies by reviewing the extant evidence base, providing clinicians with a summary of the literature on diagnosis, phenomenology and treatment of paediatric BPD. The debate regarding diagnosing children with BPD based on severe irritability and aggression is mostly resolved. The current data support utilising the diagnostic criteria based on episodic changes of mood polarity. Therefore, longitudinal course of illness should be explored in detail when diagnosing BPD. Given high rates of genetic predisposition for BPD, assessment of youth should focus on obtaining accurate family history of this condition. Additionally, there has been a substantial increase in randomised placebo-controlled clinical trials evaluating pharmacological agents for mood stabilisation in children and adolescents, which we summarise in this review. Despite significant progress being made in the field of paediatric BPD, more research is needed in the areas of phenomenology, pathophysiology, course and treatment of this condition in youth.

Modeling Complex Neurological Diseases with Stem Cells: A Study of Bipolar Disorder

The pathogenesis of bipolar disorder (BPD) is unknown. Using human-induced pluripotent stem cells (hiPSCs) to unravel pathological mechanisms in polygenic diseases is challenging, with few successful studies to date. However, hiPSCs from BPD patients responsive to lithium have offered unique opportunities to discern lithium's mechanism of action and hence gain insight into BPD pathology. By profiling the proteomics of BPD-hiPSC-derived neurons, we found that lithium alters the phosphorylation state of collapsin response mediator protein-2 (CRMP2). The "set point" for the ratio of pCRMP2:CRMP2 is elevated uniquely in hiPSC-derived neurons from lithium responsive (Li-R) BPD patients, but not other psychiatric and neurological disorders. Utilizing neurons differentiated from human patient stem cells as an in vitro platform, we were able to elucidate the mechanism driving the pathogenesis and pathophysiology of lithium-responsive BPD, heretofore unknown. Importantly, the findings in culture were validated in human postmortem material as well as in animal models of BPD behavior. These data suggest that the "lithium response pathway" in BPD governs CRMP2's phosphorylation, which regulates cytoskeletal organization, particularly in dendritic spines, leading to modulated neural networks that may underlie Li-R BPD pathogenesis. This chapter reviews the methodology of leveraging a functional agent, lithium, to identify unknown pathophysiological pathways with hiPSCs and how to translate this disease modeling approach to other neurological disorders.

Do serum BDNF levels vary in self-harm behavior among adolescents and are they correlated with traumatic experiences?

The aim of this study was to compare serum brain-derived neurotrophic factor (BDNF) levels between adolescents that harm themselves, those that receive psychiatric treatment but do not harm themselves, healthy adolescents, and childhood traumas and to investigate the relationship between traumatic experiences and serum BDNF levels. The cases were divided into two groups of 40 adolescents exhibiting self-harm behavior (self-harm/diagnosed group) and 30 adolescents receiving psychiatric treatment but not exhibiting self-harm behaviors (non self-harm/diagnosed group). The control group (healthy control group) consisted of 35 healthy adolescents with no psychiatric disorders or self-harm behaviors. The adolescents were asked to fill in the Inventory of Statements About Self Injury (ISAS) and Childhood Trauma Questionnaire (CTQ). For BDNF measurement, blood samples were taken from the cases and controls. The serum BDNF level of self-harming adolescents who used the self-cutting method was significantly lower than that of other groups, and serum BDNF levels decreased with the increase in the emotional neglect and abuse severity of self-harming adolescents during childhood. In our study, serum BDNF levels decreased with the increase in emotional abuse in self-harming adolescents. This finding may indicate that neuroplasticity can be affected by a negative emotional environment during the early period.

Conceptual issues behind the Chinese translations of the term 'Bipolar Disorder'

The paper examines the problems of the existing nomenclature in Chinese psychiatry with special reference to the Chinese translation of bipolar disorder in the context of stigma of mental illness in the Chinese culture. The development of the concept of bipolar disorder is reviewed, followed by a critical examination of the accuracy and validity of the current translation of bipolar disorder in the Chinese psychiatric literature. A new translation is suggested with consideration for literal accuracy and social acceptance.

Childhood adverse life events and parental psychopathology as risk factors for bipolar disorder

Childhood adverse events are risk factors for later bipolar disorder. We quantified the risks for a later diagnosis of bipolar disorder after exposure to adverse life events in children with and without parental psychopathology. This register-based population cohort study included all persons born in Denmark from 1980 to 1998 (980 554 persons). Adversities before age 15 years were: familial disruption; parental somatic illness; any parental psychopathology; parental labour market exclusion; parental imprisonment; placement in out-of-home care; and parental natural and unnatural death. We calculated risk estimates of each of these eight life events as single exposure and risk estimates for exposure to multiple life events. Main outcome variable was a diagnosis of bipolar disorder after the age of 15 years, analysed with Cox proportional hazard regression. Single exposure to most of the investigated adversities were associated with increased risk for bipolar disorder, exceptions were parental somatic illness and parental natural death. By far the strongest risk factor for bipolar disorder in our study was any mental disorder in the parent (hazard ratio 3.53; 95% confidence interval 2.73-4.53) and the additional effects of life events on bipolar risk were limited. An effect of early adverse life events on bipolar risk later in life was mainly observed in children without parental psychopathology. Our findings do not exclude early-life events as possible risk factors, but challenge the concept of adversities as important independent determinants of bipolar disorder in genetically vulnerable individuals.

Bipolar diagnosis in China: Evaluating diagnostic confidence using the Bipolarity Index

BACKGROUND

Diagnosis of bipolar disorder is inherently difficult. The goal of this study was to examine the utility and psychometric properties of the Bipolarity Index (BPx) in a population of patients treated in China.

METHODS

At nine Chinese health facilities participating in CAFÉ-BD, clinicians completed a standardized affective disorder evaluation for consecutive patients (N=615) with a clinical diagnosis of MDD and BPD and scored the Bipolarity Index. The investigators constructed ROC curves to determine the optimal cut off points to discriminate subjects in three clinical diagnostic groups: bipolar disorder (BPD), major depressive disorder (MDD) and healthy (no psychiatric diagnosis) controls (HC). This study is registered with ClinicalTrials.gov, number NCT02015143.

RESULTS

1) The cut-off score between the MDD and BPD groups was 42.0, with a sensitivity of 0.957 and specificity of 0.881 (Z=63.064, P<0.001); the cut-off score between the MDD and BPD II groups was 34.0, with a sensitivity of 0.810 and specificity of 0.855 (Z=20.174, P<0.001); and the cut-off score between the BPD II and BPD I groups was 57.0, with a sensitivity of 0.680 and specificity of 0.772 (Z=9.636, P<0.001). 2) Five domains contributed to the discrimination results. State-related domains (episode characteristics and course of illness) made greater contributions than trait-related domains (age of onset, family history, and treatment response).

LIMITATIONS

The data are purely descriptive. The BPD II sample and the family history dataset were small.

CONCLUSIONS

Our finding indicates good reliability and validity for the Chinese version of the BPx, which encourages its use as a measure of diagnostic confidence for bipolar spectrum disorders. Further prospective study is necessary to determine if the BPx is useful in identifying subgroups among MDD subjects at high risk for conversion to BPD.

Physical and sexual abuse and early-onset bipolar disorder in youths receiving outpatient services: frequent, but not specific

The objective of this study was to determine if physical and sexual abuse showed relationships to early-onset bipolar spectrum disorders (BPSD) consistent with findings from adult retrospective data. Participants (N = 829, M = 10.9 years old ± 3.4 SD, 60% male, 69% African American, and 18% with BPSD), primarily from a low socio-economic status, presented to an urban community mental health center and a university research center. Physical abuse was reported in 21%, sexual abuse in 20%, and both physical and sexual abuse in 11% of youths with BPSD. For youths without BPSD, physical abuse was reported in 16%, sexual abuse in 15%, and both physical and sexual abuse in 5% of youths. Among youth with BPSD, physical abuse was significantly associated with a worse global family environment, more severe depressive and manic symptoms, a greater number of sub-threshold manic/hypomanic symptoms, a greater likelihood of suicidality, a greater likelihood of being diagnosed with PTSD, and more self-reports of alcohol or drug use. Among youth with BPSD, sexual abuse was significantly associated with a worse global family environment, more severe manic symptoms, a greater number of sub-threshold manic/hypomanic symptoms, greater mood swings, more frequent episodes, more reports of past hospitalizations, and a greater number of current and past comorbid Axis I diagnoses. These findings suggest that if physical and/or sexual abuse is reported, clinicians should note that abuse appears to be related to increased severity of symptoms, substance use, greater co-morbidity, suicidality, and a worse family environment.

Association between the 5-HTTLPR Genotype and Childhood Characteristics in Mood Disorders

Objective

The features of childhood attention deficit hyperactivity disorder (ADHD) are significantly associated with adult mood disorders. Some genetic factors may be common to both ADHD and mood disorders underlie the association between these two phenotypes. The present study aimed to determine whether a genetic role may be played by the serotonin transporter-linked polymorphic region (5-HTTLPR) in the childhood ADHD features of adult patients with mood disorders.

Methods

The present study included 232 patients with major depressive disorder (MDD), 154 patients with bipolar disorder (BPD), and 1,288 normal controls. Childhood ADHD features were assessed with the Korean version of the Wender Utah Rating Scale (WURS-K). The total score and the scores of three factors (impulsivity, inattention, and mood instability) from the WURS-K were analyzed to determine whether they were associated with the 5-HTTLPR genotype.

Results

In the BPD type II group, the 5-HTTLPR genotype was significantly associated with the total score (p=0.029) and the impulsivity factor (p=0.004) on the WURS-K. However, the inattention and mood instability factors were not associated with the 5-HTTLPR genotype. BPD type I, MDD and normal control groups did not exhibit any significant associations between the WURS-K scores and the 5-HTTLPR genotype.

Conclusion

The findings suggest that the 5-HTTLPR genotype may play a role in the impulsivity component of childhood ADHD in patients with BPD type II. Because of a small sample size and a single candidate gene, further studies investigating other candidate genes using a larger sample are warranted to determine any common genetic links.

Bipolar Disorder Among Children and Adolescents

Although for years it was felt to be almost nonexistent, very-early-onset bipolar disorder (before age 12) has become an important member of the mood disorder spectrum of youths. Whether there is a separate subtype characterized by severe irritability or whether the problem of emotionally explosive children is better explained by other conditions is still being resolved. The diagnosis of bipolar I disorder requires an episode of mania, and understanding those manic symptoms is the source of differences in interpretation.

Association study of TPH2 polymorphisms and bipolar disorder in the Han Chinese population

OBJECTIVE

Bipolar disorder (BPD) is a serious and common mental disorder with high heritability. The serotonergic system is known to be implicated in the etiology of the disorder. Tryptophan hydroxylase isoform-2 (TPH2), which controls the synthesis of serotonin in the brain, has been suggested as a candidate gene for BDP. The aim of this study was to examine the association between the polymorphisms in TPH2 and BPD.

METHODS

We conducted a case-control study by genotyping six SNPs (rs10784941, rs1386494, rs2171363, rs4760816, rs1386486, and rs1872824) in 506 bipolar patients and 507 controls of Chinese Han origin.

RESULTS

rs10784941 was not in the Hardy-Weinberg equilibrium and therefore excluded from further analysis. rs1386486 and rs1872824 showed statistically significant differences between cases and controls in genotype frequencies (rs1386486: p=0.043351; rs1872824: p=0.016563), but no association in allele frequencies. Strong LD was found among rs1386494, rs2171363 and rs4760816, but no positive association with BPD was found for haplotypes.

CONCLUSION

Our results indicate that in the Han Chinese population TPH2 may be a potential susceptibility gene for bipolar disorder. Further studies are needed to validate this association.

A genome-wide linkage scan of bipolar disorder in Latino families identifies susceptibility loci at 8q24 and 14q32

A genome-wide nonparametric linkage screen was performed to localize Bipolar Disorder (BP) susceptibility loci in a sample of 3757 individuals of Latino ancestry. The sample included 963 individuals with BP phenotype (704 relative pairs) from 686 families recruited from the US, Mexico, Costa Rica, and Guatemala. Non-parametric analyses were performed over a 5 cM grid with an average genetic coverage of 0.67 cM. Multipoint analyses were conducted across the genome using non-parametric Kong & Cox LOD scores along with Sall statistics for all relative pairs. Suggestive and significant genome-wide thresholds were calculated based on 1000 simulations. Single-marker association tests in the presence of linkage were performed assuming a multiplicative model with a population prevalence of 2%. We identified two genome-wide significant susceptibly loci for BP at 8q24 and 14q32, and a third suggestive locus at 2q13-q14. Within these three linkage regions, the top associated single marker (rs1847694, P = 2.40 × 10(-5)) is located 195 Kb upstream of DPP10 in Chromosome 2. DPP10 is prominently expressed in brain neuronal populations, where it has been shown to bind and regulate Kv4-mediated A-type potassium channels. Taken together, these results provide additional evidence that 8q24, 14q32, and 2q13-q14 are susceptibly loci for BP and these regions may be involved in the pathogenesis of BP in the Latino population.

Dysfunctional family environment in affected versus unaffected offspring of parents with bipolar disorder

OBJECTIVE

Children of parents with bipolar disorder (BD) are at heightened risk for developing mood and other psychiatric disorders. We proposed to evaluate the environment of families with at least one parent with BD type I (BDF) with affected offspring (aBDF) and unaffected offspring (uBDF) compared with control families without a history of DSM-IV Axis I disorder (CF).

METHOD

We used the Family Environment Scale (FES) to evaluate 47 BDF (aBDF + uBDF) and 30 CF. Parents were assessed through the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I). Diagnosis of the offspring was determined through the Schedule for Affective Disorders and Schizophrenia for School-Age Children/Present and Lifetime Version (K-SADS-PL) interview.

RESULTS

There were statistically significant differences between aBDF, uBDF and CF in cohesion (p = 0.003), intellectual-cultural orientation (p = 0.01), active-recreational orientation (p = 0.007), conflict (p = 0.001), control (p = 0.01), moral-religious emphasis (p = 0.01) and organization (p = 0.001). The aBDF showed higher levels of control (p = 0.02) when compared to the uBDF.

CONCLUSIONS

Families with a BD parent presented more dysfunctional interactions among members. Moreover, the presence of BD or other psychiatric disorders in the offspring of parents with BD is associated with higher levels of control. These results highlight the relevance of psychosocial interventions to improve resilience and family interactions.

Can pediatric bipolar-I disorder be diagnosed in the context of posttraumatic stress disorder? A familial risk analysis

Despite ongoing concerns that traumatized children with severe symptoms of emotional dysregulation may be inappropriately receiving a diagnosis of pediatric bipolar-I (BP-I) disorder, this issue has not been adequately examined in the literature. Because both pediatric BP-I disorder and posttraumatic stress disorder (PTSD) are familial disorders, if children with both BP-I and PTSD were to be truly affected with BP-I disorder, their relatives would be at high risk for BP-I disorder. To this end, we compared patterns of familial aggregation of BP-I disorder in BP-I children with and without PTSD with age and sex matched controls. Participants were 236 youths with BP-I disorder and 136 controls of both sexes along with their siblings. Participants completed a large battery of measures designed to assess psychiatric disorders, psychosocial, educational, and cognitive parameters. Familial risk analysis revealed that relatives of BP-I probands with and without PTSD had similar elevated rates of BP-I disorder that significantly differed from those of relatives of controls. Pediatric BP-I disorder is similarly highly familial in probands with and without PTSD indicating that their co-occurrence is not due to diagnostic error.

Negative expressed emotion best discriminates families with bipolar disorder children

BACKGROUND

Children and adolescents with bipolar disorder (BD) live in family environments with high levels of expressed emotion (EE), conflict, and tension; as well as low maternal warmth and cohesion. These family characteristics have been evaluated in research settings using different scales. Nonetheless, empirically supported assessment instruments are not always feasible to be used in clinical settings. Our aim was to identify the best characteristics that discriminate BD families from control by building a classifier with the main characteristics found from different scales. We also built a classifier based on the adjective check-list scale (ACL) because this scale would be the most feasible one to be used in clinical setting.

METHODS

We evaluated 33 families of pediatric BD patients and 29 control families. Two self-report scales, ACL and the Family Environment Scale (FES), and a direct interview scale, the Psychosocial Schedule for School Age Children-Revised (PSS-R), were administered.

RESULTS

BD families presented lower positive EE and higher negative EE, less cohesion, organization, greater conflict and control; lower rate of intact family, higher maternal and paternal tension compared to control families. Both classifiers demonstrated high accuracy. The offspring's EE toward the mother was the family characteristic that best discriminated BD from control families.

LIMITATIONS

Small sample size and cross-sectional design.

CONCLUSIONS

Families of BD children presented altered communication and functioning. The high accuracy of the ACL-based classifier highlights a feasible scale to be used in clinical settings. Further studies assessing prognosis associated with the patterns of communication in such families are needed.

Further evidence for robust familiality of pediatric bipolar I disorder: results from a very large controlled family study of pediatric bipolar I disorder and a meta-analysis

OBJECTIVE

To determine the risk for bipolar I disorder in first-degree relatives of children with DSM-IV bipolar I disorder via meta-analysis and expanded controlled study.

DATA SOURCES AND EXTRACTION

For the meta-analysis, PubMed was searched for scientific articles published in the world literature in English through 2011. The keywords searched were bipolar disorder, first-degree relatives, family study, and control. All online abstracts were reviewed, and relevant full manuscripts were collected and reviewed. Citations were also examined for other potentially relevant articles. The analysis included only controlled family studies that examined rates of bipolar I disorder in all first-degree relatives (parents and siblings) of pediatric bipolar I probands and that had age- and sex-matched controls. Family history studies were excluded, as were studies that were not in English, did not report bipolar I rates for all first-degree relatives, or reported only bipolar spectrum rates. Also excluded were family studies that included only adult probands. A meta-analysis was conducted of the 5 controlled family studies of pediatric bipolar I probands that met the search criteria using the random-effects model of DerSimonian and Laird.

METHOD

For the family study, our previous sample of DSM-IV bipolar I probands was greatly expanded using structured diagnostic interviews. The new study included 239 children aged 6-17 years who satisfied full DSM-IV diagnostic criteria for bipolar I disorder (n = 726 first-degree relatives), 162 attention-deficit/hyperactivity disorder (ADHD) probands (without bipolar I disorder; n = 511 first-degree relatives), and 136 healthy control probands (without ADHD or bipolar I disorder; n = 411 first-degree relatives). The Kaplan-Meier cumulative failure function was used to calculate survival curves and cumulative lifetime risk in relatives. Cox proportional hazard models were used to calculate the risk of bipolar I disorder in relatives.

RESULTS

The pooled odds ratio for bipolar I disorder in relatives was estimated to be 6.96 (95% confidence interval [CI], 4.8-10.1). First-degree relatives of bipolar I probands were also significantly more likely than first-degree relatives of both ADHD probands (hazard ratio [HR] = 3.02; 95% CI, 1.85-4.93; P < .001) and control probands (HR = 2.83; 95% CI, 1.65-4.84; P < .001) to have bipolar I disorder.

CONCLUSIONS

Our results document an increased familial risk for bipolar I disorder in relatives of pediatric probands with DSM-IV bipolar I disorder.

Childhood attention deficit hyperactivity disorder features in adult mood disorders

A significant overlap between childhood mood disorders and many aspects of attention deficit hyperactivity disorder (ADHD) has been established. High rates of co-occurrence, familial aggregation, and more severe clinical manifestations of the illnesses when they are comorbid suggest that common genetic and environmental factors may contribute to the development of both disorders. Research on the co-occurrence of childhood ADHD and mood disorders in childhood has been conducted. We retrospectively investigated childhood ADHD features in adults with mood disorders. Childhood ADHD features were measured with the Korean version of the Wender Utah Rating Scale (WURS). The sample consisted of 1305 subjects: 108 subjects were diagnosed with bipolar disorder type I, 41 with bipolar disorder type II, 101 with major depressive disorder, and 1055 served as normal controls. We compared total WURS scores as well as scores on 3 factors (impulsivity, inattention, and mood instability and anxiety) among the 4 different diagnostic groups. The 4 groups differed significantly from one another on all scores. The group with bipolar disorder type II obtained the highest total scores on the WURS. The impulsivity and inattention associated with childhood ADHD were more significantly related to bipolar disorder type II than with bipolar disorder type I. The mood instability and anxiety associated with childhood ADHD seem to be significantly related to major depressive disorder in adulthood. In conclusion, multifactorial childhood ADHD features were associated with mood disorders of adulthood.

The BDNF Val66Met polymorphism is an independent risk factor for high lethality in suicide attempts of depressed patients

Some authors have reported an association of BDNF Val66Met polymorphism with suicidal behavior and/or clinical aspects of suicidal attempts. We evaluated, here, the impact of BDNF Val66Met polymorphism on the clinical characteristics of suicide attempts. The study was conducted on a cohort of 120 consecutive patients who were admitted to the Emergency Hospital of Porto Alegre, Brazil, due to a suicide attempt. Variables of univariate analyses were included in a logistic regression model to test whether the risk factors had independent effect. In univariate analyses, sex, BDNF genotype, intent and method of suicide attempt were all risk factors for high lethality in suicide attempts. After logistic regression analysis, male sex (O.R.=3.03; 95% C.I=1.34-6.84; 0.008) and the presence of BDNF 66Met allele (O.R.=2.62; 95% C.I=1.04-6.57; 0.04) were significantly and independently associated with the high lethality in suicide attempts. The present study showed that BDNF 66Met allele is an independent predictor of high lethality in suicide attempts of depressed patients. This finding is important because it might allow earlier identification of patients at high risk for suicide, perhaps providing better tools for clinical care of these patients in the future.

Suggestive evidence for linkage of ADHD features in bipolar disorder to chromosome 10p14

Higher rates of bipolar disorder amongst the first-degree relatives of probands with ADHD, and increased rates of ADHD in the relatives of bipolar probands have been reported in many studies. This suggests some commonality in the genetic basis for bipolar disorder and ADHD. We hypothesized that ADHD symptoms in bipolar disorder may access a quantitative subphenotype that is genetically less complex and therefore advantageous for mapping studies. The Wender Utah Rating Scale (WURS) was used to quantify ADHD features in 57 bipolar families collected for linkage studies. The factor structure of the WURS was first examined, and heritability was estimated. Linkage analysis was then conducted using the WURS total score and factor scores as quantitative traits. Three factors were identified: impulsivity and defiant behavior, mood instability and anxiety, and inattention. The total WURS and factor scores were each significantly heritable (0.34 <h(2r) < 0.49) in bipolar families. The inattention factor obtained maximum evidence of linkage on chromosome 10p14 (LOD = 3.35, 25 cM). A LOD score of 2.06 for the total WURS score was found on chromosome 12q24 region. Childhood ADHD features in patients with bipolar disorder are heritable and may represent a genetically distinct dimension of illness. 10p14, in particular may contain a locus for inattention in bipolar disorder. Quantitative dimensional phenotypes such as this may be useful for both mapping of genes and understanding the role of genes in bipolar disorder.

Family environment and pediatric major depressive disorder

BACKGROUND

The risks for depression broadly include biological and environmental factors. Furthermore, having a family member suffering from major depression is also likely to have consequences for the family environment. Further research aimed at understanding the effects of having a child with major depression on family interaction patterns is warranted.

METHODS

We studied 31 families with an 8- to 17-year-old child (mean age +/- SD = 12.9 +/- 2.7 years) who met the DSM-IV criteria for major depressive disorder (MDD) and 34 families with no mentally ill children (mean age +/- SD = 12.6 +/- 2.9 years) or parents. Children and their parents were assessed with the K-SADS-PL (Kiddie Schedule for Affective Disorders and Schizophrenia--Present and Lifetime Version) interview. Parents completed the Moos Family Environment Scale (FES) to assess their perceptions of current family functioning. Data were analyzed using the nonparametric Wilcoxon-Mann-Whitney test.

RESULTS

Families of MDD children showed significantly different patterns of family functioning on FES subscales representing relationships and personal growth dimensions. The families with MDD children showed higher levels of conflict (p < 0.001) and lower levels of cohesion (p < 0.001), expressiveness (p = 0.003) and active-recreational orientation (p = 0.02) compared to the families without mentally ill children.

CONCLUSION

Families with MDD children show a lower degree of commitment, provide less support to one another, provide less encouragement to express feelings and have more conflicts compared to families with no mentally ill children or parents. Interventions aimed at improving family dynamics may be beneficial to MDD children and their families.

Moléculas que marcam o tempo: implicações para os fenótipos circadianos

OBJETIVO: Revisar resumidamente a literatura dos últimos 36 anos de pesquisa em cronobiologia molecular a fim de informar aos profissionais de saúde os avanços obtidos nesta área e os potenciais para aplicação na clínica médica. MÉTODO: Buscas na literatura foram realizadas utilizando as bases de dados PubMed e Scopus usando como palavras-chave "clock genes, circadian rhythms, diurnal preference, delayed sleep phase syndrome, advanced sleep phase syndrome, photoperiod and mood disorder". DISCUSSÃO: Atualmente, o mecanismo molecular da regulação da ritmicidade circadiana é compreendido em grande detalhe. Muitos estudos publicados mostram associações de polimorfismos nos genes relógio com transtornos do ritmo circadiano e com transtornos do humor. CONCLUSÕES: De maneira geral, o progresso obtido na área de cronobiologia molecular traz um melhor entendimento da regulação do sistema de temporização biológico. O desenvolvimento de estudos nesta área tem o potencial de ser aplicável ao tratamento dos transtornos dos ritmos circadianos e certos transtornos do humor, além de prevenir riscos à saúde causados por viagens intercontinentais (Jet Lag) e por trabalhos noturnos e por turnos.

AACAP 2006 Research Forum--Advancing research in early-onset bipolar disorder: barriers and suggestions

OBJECTIVE

The 2006 Research Forum addressed the goal of formulating a research agenda for early-onset bipolar disorder (EOBP) and improving outcome by understanding the risk and protective factors that contribute to its severity and chronicity.

METHOD

Five work groups outlined barriers and research gaps in EOBP genetics, neuroimaging, prodromes, psychosocial factors, and pharmacotherapy.

RESULTS

There was agreement that the lack of consensus on the definition and diagnosis of EOBP is the primary barrier to advancing research in BP in children and adolescents. Related issues included: the difficulties in managing co-morbidity both statistically and clinically; acquiring adequate sample sizes to study the genetics, biology, and treatment; understanding the EOBP's developmental aspects; and identifying environmental mediators and moderators of risk and protection. Similarly, both psychosocial and medication treatment strategies for children with BP are hamstrung by diagnostic issues. To advance the research in EOBP, both training and funding mechanisms need to be developed with these issues in mind.

CONCLUSIONS

EOBP constitutes a significant public health concern. Barriers are significant but identifiable and thus are not insurmountable. To advance the understanding of EOBP, the field must be committed to resolving diagnostic and assessment issues. Once achieved, with adequate personnel and funding resources, research into the field of EOBP will doubtless be advanced at a rapid pace.

Neither single-marker nor haplotype analyses support an association between monoamine oxidase A gene and bipolar disorder

Monoamine oxidase A (MAOA) abnormality has been suggested as a crucial factor in the pathogenesis of mood disorder, because MAOA is associated with the metabolism of monoamines such as serotonin and norepinephrine. Various MAOA gene polymorphisms have been investigated for possible associations with bipolar disorder (BD), but the results are controversial. Our goal was to investigate whether MAOA gene polymorphisms, especially the promoter uVNTR polymorphism and the EcoRV polymorphism, are associated either with BD or with different clinical subtypes of BD. A total of 714 Han Chinese subjects in Taiwan (305 controls and 409 BD patients) were recruited for study. All subjects were interviewed with the Chinese Version of the Modified Schedule of Affective Disorders and Schizophrenia-Lifetime; BD was diagnosed according to DSM-IV criteria. Genotyping for MAOA polymorphisms was performed using PCR and restriction fragment length polymorphism. The MAOA promoter polymorphisms uVNTR and EcoRV were not associated with BD or any of its subtypes, in either the frequencies of alleles or genotypes. In multiple logistic regression and haplotype frequency analysis, we confirmed these negative results in both females and males. Our results suggest that MAOA polymorphisms do not play a major role in pathogenesis of BD or its clinical subtypes in Han Chinese.

Face emotion labeling deficits in children with bipolar disorder and severe mood dysregulation

Children with narrow phenotype bipolar disorder (NP-BD; i.e., history of at least one hypomanic or manic episode with euphoric mood) are deficient when labeling face emotions. It is unknown if this deficit is specific to particular emotions, or if it extends to children with severe mood dysregulation (SMD; i.e., chronic irritability and hyperarousal without episodes of mania). Thirty-nine NP-BD, 31 SMD, and 36 control subjects completed the emotional expression multimorph task, which presents gradations of facial emotions from 100% neutrality to 100% emotional expression (happiness, surprise, fear, sadness, anger, and disgust). Groups were compared in terms of intensity of emotion required before identification occurred and accuracy. Both NP-BD and SMD youth required significantly more morphs than controls to label correctly disgusted, surprised, fearful, and happy faces. Impaired face labeling correlated with deficient social reciprocity skills in NP-BD youth and dysfunctional family relationships in SMD youth. Compared to controls, patients with NP-BD or SMD require significantly more intense facial emotion before they are able to label the emotion correctly. These deficits are associated with psychosocial impairments. Understanding the neural circuitry associated with face-labeling deficits has the potential to clarify the pathophysiology of these disorders.

[The genetics of depressive disorders]

Among the most common severe psychiatric disorders worldwide, depressive disorders are a leading cause of morbidity, the onset usually occurring during childhood or adolescence. Symptomatology, prevalence, outcome and treatment differentiate depressive disorder nosologically as being either unipolar depression or bipolar disorder, which is characterized by one or more episodes of mania with or without episodes of depression. Genetic factors decisively influence the susceptibility to depressive disorders. Family studies and twin studies have been essential in defining the magnitude of familial risk and liability to heritability, particularly in the case of bipolar disorder. In recent years, linkage and association studies have made great strides towards identifying candidate genes. Particularly the s-allele of the serotonin transporter has been repeatedly confirmed to be a risk factor. Meta-analyses suggest, however, that the genetic contributions of the ascertained loci are relatively small. Along with genetic factors, environmental factors are heavily involved. Gene-environment action plays a pivotal role, particularly in unipolar depression. The genetic disposition seems to be modulated by a protective or pathogenic environment. Early-onset disorders must be further investigated in future as studies to date are somewhat limited.

Effect of the dysbindin gene on antimanic agents in patients with bipolar I disorder

OBJECTIVE

We previously reported an association between dysbindin gene (DTNBP1) variants and bipolar I disorder (BID). This paper expands upon previous findings suggesting that DTNBP1 variants may play a role in the response to acute mood stabilizer treatment.

METHODS

A total of 45 BID patients were treated with antimanic agents (lithium, valproate, or carbamazepine) for an average of 36.52 (+/-19.87) days. After treatment, the patients were evaluated using the Clinical Global Impression (CGI) scale and the Young Mania Rating Scale (YMRS) and genotyped for their DTNBP1 variants (rs3213207 A/G, rs1011313 C/T, rs2005976 G/A, rs760761 C/T and rs2619522 A/C).

RESULTS

There was no association between the variants investigated and response to mood stabilizer treatment, even after considering possible stratification factors.

CONCLUSION

Although the small number of subjects is an important limitation in our study, DTNBP1 does not seem to be involved in acute antimanic efficacy.

Family environment patterns in families with bipolar children

BACKGROUND

We studied the characteristics of family functioning in bipolar children and healthy comparison children. We hypothesized that the family environment of bipolar children would show greater levels of dysfunction as measured by the Family Environment Scale (FES).

METHODS

We compared the family functioning of 36 families that included a child with DSM-IV bipolar disorder versus 29 comparison families that included only healthy children. All subjects and their parents were assessed with the K-SADS-PL interview. The parents completed the FES to assess their current family functioning. Multivariate analysis of variance was used to compare the family environment of families with and without offspring with bipolar disorder.

RESULTS

Parents of bipolar children reported lower levels of family cohesion (p<0.001), expressiveness (p=0.005), active-recreational orientation (p<0.001), intellectual-cultural orientation (p=0.04) and higher levels of conflict (p<0.001) compared to parents with no bipolar children. Secondary analyses within the bipolar group revealed lower levels of organization (p=0.031) and cohesion (p=0.014) in families where a parent had a history of mood disorders compared to families where parents had no history of mood disorders. Length of illness in the affected child was inversely associated with family cohesion (r=-0.47, p=0.004).

LIMITATIONS

Due to the case-control design of the study, we cannot comment on the development of these family problems or attribute their cause specifically to child bipolar disorder.

CONCLUSION

Families with bipolar children show dysfunctional patterns related to interpersonal interactions and personal growth. A distressed family environment should be addressed when treating children with bipolar disorder.

Increased rates of bipolar disorder diagnoses among U.S. child, adolescent, and adult inpatients, 1996-2004

BACKGROUND

Volatile, aggressive behavior is the chief complaint that brings children to inpatient psychiatric care. These difficulties are increasingly conceptualized as bipolar disorder (BD). The impact of doing so on clinical diagnoses in clinical care is uncertain.

METHODS

We extracted records from the annual National Hospital Discharge Survey (NHDS) for which a psychiatric diagnosis was primary and examined trends in the rates of hospitalization for BD.

RESULTS

Population-adjusted rates of hospital discharges of children with a primary diagnosis of BD increased linearly over survey years. The rate in 1996 was 1.3 per 10,000 U.S. children and climbed to 7.3 per 10,000 U.S. children in 2004. Bipolar disorder related discharges also increased fourfold among adolescents. Adults showed a more modest, though still marked, rise of 56%. Bipolar disorder related hospitalization was more prevalent among female adolescents and adults, while male children had larger risk than female children. Children's BD diagnoses tended not to specify a prevailing mood state, while depression and psychotic features were the most common codes for adults. Black individuals, especially men, had lower rates of BD diagnoses in early survey years, but more recently their rate of BD related hospitalizations has exceeded other NHDS race groups.

CONCLUSIONS

Higher rates of inpatient admissions among youth associated with BD may reflect greater appreciation of the importance of affective dysregulation in this patient group or "upcoding" to putatively more severe conditions for reimbursement or administrative reasons. Further study is warranted to examine this shift's causes and implications for treatments and outcomes.

Adult bipolar disorder is continuous with pediatric bipolar disorder

Considerable debate exists regarding the continuity of bipolar disorder (BD) in children and adolescents. Do affected children continue to have BD as adults? Are pediatric forms of BD distinct from adult forms of the disorder? Here, I argue that, in fact, strictly defined BD I and II in children and adolescents is continuous with adult BD. First, if we take developmental differences into account, children and adults share similar symptoms, since they are both diagnosed according to DSM-IV criteria. Next, retrospective studies indicate that 50% to 66% of adults with BD had onset of their disorder before age 19 years. Early prospective data indicate that adolescents with BD progress to become young adults with BD. Further, family studies of pediatric BD probands find high rates of BD in adult relatives, and pediatric offspring of parents with BD have elevated rates of BD, compared with control subjects. Finally, biological characteristics of pediatric BD (such as treatment response, neurobiology, and genetics) are either shared with adults having BD or fit logically into developmental models of BD. Thus, while not conclusive, a preponderance of data support the hypothesis that pediatric BD is continuous with adult BD. Prospective studies incorporating phenomenological and biological assessment are needed to decisively address this issue.

Early identification and high-risk strategies for bipolar disorder

OBJECTIVES

To describe and compare the relative merits of different identification strategies for individuals at risk for bipolar disorder (BPD).

METHODS

Selective review of data that support early identification in BPD, with a particular focus on emerging clinical high-risk strategies.

RESULTS

Early detection of individuals at risk for BPD can utilize genetic, endophenotypic and clinical methods. Most published work focuses on genetic familial endophenotypic risk markers for BPD. However, despite encouraging results, problems with specificity and sensitivity limit the application of these data to early prevention programs. In addition, offspring studies of BPD patients systematically exclude the majority of subjects without a first-degree bipolar relative. On the other hand, emerging work in the clinical-high-risk arena has already produced encouraging results. Although still preliminary, the identification of individuals in subsyndromal or attenuated symptom 'prodromal' stages of BPD seems to be an under-researched area that holds considerable promise deserving increased attention. Required next steps include the development of rating tools for attenuated and subsyndromal manic and depressive symptoms and of prodromal criteria that will allow prodromal symptomatology to be systematically studied in patients with recent-onset bipolar, as well as in prospective population-based phenomenology trials and attenuated symptom-based high-risk studies.

CONCLUSIONS

Given the current limitations of each early identification method, combining clinical, endophenotypic and genetic strategies will increase prediction accuracy. Since reliable biological markers for BPD have not been established and since most patients with BPD lack a first-degree relative with this disorder, clinical high-risk approaches have great potential to inform early identification and intervention programs.

Childhood-onset bipolar disorder: Evidence for increased familial loading of psychiatric illness

OBJECTIVE

To determine whether childhood-onset bipolar disorder (BP) is associated with an increased psychiatric family history compared with adolescent-onset BP.

METHOD

Semistructured psychiatric interviews were conducted for 438 youth with BP spectrum disorders. To evaluate the effects of age at onset and psychiatric family history, the sample was divided into childhood-onset BP (age and BP onset <12 years; n = 192), adolescents with early-onset BP (age > or =12 years and BP onset <12 years; n = 136), and adolescents with late-onset BP (age and BP onset > or =12 years; n = 110). Lifetime family history of psychiatric illness was ascertained for first- and second-degree relatives through both direct interview of caretakers and the Family History Screen.

RESULTS

After significant demographic and clinical factors were controlled for, children and adolescents with childhood-onset BP showed higher percentages of positive first-degree family history for depression, anxiety, attention-deficit/hyperactivity, conduct, and substance dependence disorders and suicidal behaviors compared with adolescents with late onset. Subjects with childhood-onset BP also showed elevated familial loading for depression and attention-deficit/hyperactive disorder in second-degree relatives.

CONCLUSIONS

These data support a model that postulates a higher density of familial risk for a broad range of psychopathology in childhood-onset BP.

A model for the involvement of neural cell adhesion molecules in stress-related mood disorders

Critical interactions between genetic and environmental factors -- among which stress is one of the most potent non-genomic factors -- are involved in the development of mood disorders. Intensive work during the past decade has led to the proposal of the network hypothesis of depression [Castren E: Nat Rev Neurosci 2005;6:241-246]. In contrast to the earlier chemical hypothesis of depression that emphasized neurochemical imbalance as the cause of depression, the network hypothesis proposes that problems in information processing within relevant neural networks might underlie mood disorders. Clinical and preclinical evidence supporting this hypothesis are mainly based on observations from depressed patients and animal stress models indicating atrophy (with basic research pointing at structural remodeling and decreased neurogenesis as underlying mechanisms) and malfunctioning of the hippocampus and prefrontal cortex, as well as the ability of antidepressant treatments to have the opposite effects. A great research effort is devoted to identify the molecular mechanisms that are responsible for the network effects of depression and antidepressant actions, with a great deal of evidence pointing at a key role of neurotrophins (notably the brain-derived neurotrophic factor) and other growth factors. In this review, we present evidence that implicates alterations in the levels of the neural cell adhesion molecules of the immunoglobulin superfamily, NCAM and L1, among the mechanisms contributing to stress-related mood disorders and, potentially, in antidepressant action.

Prevention of Pediatric Bipolar Disorder: Integration of Neurobiological and Psychosocial Processes

Bipolar disorder (BD) is a prevalent condition in the United States that typically begins before the age of 18 years and is being increasingly recognized in children and adolescents. Despite great efforts in discovering more effective treatments for BD, it remains a difficult-to-treat condition with high morbidity and mortality. Therefore, it appears prudent to focus energies into developing interventions designed to prevent individuals from ever fully developing BD. Such interventions early in the development of the illness might prevent inappropriate interventions that may worsen or hasten development of BD, delay the onset of first manic episode, and/or prevent development of full BD. Studies of populations at high-risk for BD development have indicated that children with strong family histories of BD, who are themselves experiencing symptoms of attention-deficit/hyperactive disorder (ADHD) and/or depression or have early mood dysregulation, may be experiencing prodromal states of BD. Understanding the neurobiological and genetic underpinnings that create risk for BD development would help with more accurate identification of this prodromal population, which could then lead to suitable preventative interventions. Such interventions could be pharmacologic or psychosocial in nature. Reductions in stress and increases in coping abilities through psychosocial interventions could decrease the chance of a future manic episode. Similarly, psychotropic medications may decrease negative sequelae of stress and have potential for neuroprotective and neurogenic effects that may contribute to prevention of fully expressed BD. Further research into the biologic and environmental mechanisms of BD development as well as controlled early intervention studies are needed to ameliorate this significant public health problem.

Longitudinal stability of the CBCL-juvenile bipolar disorder phenotype: A study in Dutch twins

BACKGROUND

The Child Behavior Checklist-juvenile bipolar disorder phenotype (CBCL-JBD) is a quantitative phenotype that is based on parental ratings of the behavior of the child. The phenotype is predictive of DSM-IV characterizations of BD and has been shown to be sensitive and specific. Its genetic architecture differs from that for inattentive, aggressive, or anxious-depressed syndromes. The purpose of this study is to assess the developmental stability of the CBCL-JBD phenotype across ages 7, 10, and 12 years in a large population-based twin sample and to examine its genetic architecture.

METHODS

Longitudinal data on Dutch mono- and dizygotic twin pairs (N = 8013 pairs) are analyzed to decompose the stability of the CBCL-JBD phenotype into genetic and environmental contributions.

RESULTS

Heritability of the CBCL-JBD increases with age (from 63% to 75%), whereas the effects of shared environment decrease (from 20% to 8%). The stability of the CBCL-JBD phenotype is high, with correlations between .66 and .77 across ages 7, 10, and 12 years. Genetic factors account for the majority of the stability of this phenotype. There were no sex differences in genetic architecture.

CONCLUSIONS

Roughly 80% of the stability in childhood CBCL-JBD is a result of additive genetic effects.

Latent class analysis shows strong heritability of the child behavior checklist-juvenile bipolar phenotype

BACKGROUND

The Child Behavior Checklist (CBCL) has been used to provide a quantitative description of childhood bipolar disorder (BPAD). Many have reported that children in the clinical range on the Attention Problems (AP), Aggressive Behavior (AGG), and Anxious-Depressed (A/D) syndromes simultaneously are more likely to meet the criteria for childhood BPAD. The purpose of this study was to determine if Latent Class Analysis (LCA) could identify heritable phenotypes representing the CBCL-Juvenile Bipolar (CBCL-JBD) profile and whether this phenotype demonstrates increased frequency of suicidal endorsement.

METHODS

The CBCL data were received by survey of mothers of twins in two large twin samples, the Netherlands Twin Registry. The setting for the study was the general community twin sample. Participants included 6246 10-year-old Dutch twins from the Netherlands Twin Registry. The main outcome measure consisted of the LCA on the items comprising the AP, AGG, and A/D subscales and means from the suicidal items #18 and #91 within classes.

RESULTS

A 7 class model fit best for girls and an 8 class fit best for boys. The most common class for boys or girls was one with no symptoms. The CBCL-JBD phenotype was the least common--about 4%-5% of the boys and girls. This class was the only one that had significant elevations on the suicidal items of the CBCL. Gender differences were present across latent classes with girls showing no aggression without the CBCL-JBD phenotype and rarely showing attention problems in isolation. Evidence of high heritability of these latent classes was found with odds ratios.

CONCLUSIONS

In a general population sample, LCA identifies a CBCL-JBD phenotype latent class that is associated with high rates of suicidality, is highly heritable, and speaks to the comorbidity between attention problems, aggressive behavior, and anxious/depression in children.

Animal Models and Human Neuropsychiatric Disorders

Humans have long distinguished themselves from other living organisms. Therefore, to make use of animal models for neuropsychiatric disorders, it is important to acknowledge what has changed historically. Darwin argued that there was continuity in mind between humans and nonhuman species, and animal experimental psychologists and others have debated the existence of consciousness and mentality in animals ever since. Those trained in the associationist tradition sought to eliminate the concept of mind in favor of an empiricial, behavioral approach; others trained in the introspectionist tradition sought to include mental abilities as an integral part of comparative animal psychology. The waning of behaviorism and ascendance of cognitive psychology in the mid-twentieth century renewed interest in the notion of consciousness and mind in nonhuman organisms, particularly as they related to learning impairment and neurobehavioral disorders. Moreover, advances in molecular genetics and technology facilitated development of genetically modified mouse strains that could be used to examine cognitive deficits and psychopathology. However, genetic modifications to individual genes that produce behavioral dysfunction in the mouse have not always provided clear results. In part, this is likely due to the influence of genes in addition to the targeted gene, sometimes resulting in paradoxical effects. I also examine other issues created by the use of nonhuman models of human disorders, including: language, the effect of background genetic strains, genetic-environmental interactions, and the problems associated with the complex genetics needed to produce similarly complex behavioral phenotypes.