A family study of bipolar I disorder in adolescence. Early onset of symptoms linked to increased familial loading and lithium resistance

Morphological abnormalities in youth with bipolar disorder and their relationship to clinical characteristics

OBJECTIVES

To characterize the neuroanatomy of BD in youth and its correlation to clinical characteristics.

METHODS

The current study includes a sample of 105 unmedicated youth with first-episode BD, aged between 10.1 and 17.9 years, and 61 healthy comparison adolescents, aged between 10.1 and 17.7 years, who were matched for age, race, sex, socioeconomic status, intelligence quotient (IQ), and education level. T1-weighted magnetic resonance imaging (MRI) images were obtained using a 4 T MRI scanner. Freesurfer (V6.0) was used to preprocess and parcellate the structural data, and 68 cortical and 12 subcortical regions were considered for statistical comparisons. The relationship between morphological deficits and clinical and demographic characteristics were evaluated using linear models.

RESULTS

Compared with healthy youth, youth with BD had decreased cortical thickness in frontal, parietal, and anterior cingulate regions. These youth also showed decreased gray matter volumes in 6 of the 12 subcortical regions examined including thalamus, putamen, amygdala and caudate. In further subgroup analyses, we found that youth with BD with comorbid attention-deficit hyperactivity disorder (ADHD) or with psychotic symptoms had more significant deficits in subcortical gray matter volume.

LIMITATIONS

We cannot provide information about the course of structural changes and impact of treatment and illness progression.

CONCLUSIONS

Our findings indicate that youth with BD have significant neurostructural deficits in both cortical and subcortical regions mainly located in the regions related to emotion processing and regulation. Variability in clinical characteristics and comorbidities may contribute to the severity of anatomic alterations in this disorder.

Mild Behavioral Impairment in Psychogeriatric Patients: Clinical Features and Psychopathology Severity

The Mild Behavioral Impairment (MBI) concept was developed to determine whether late-onset persistent neuropsychiatric symptoms (NPSs) may be early manifestations of cognitive decline. Our study aims to investigate the prevalence and differentiating features of MBI with respect to major neurocognitive disorders (MNDs) and primary psychiatric disorders (PPDs). A total of 144 elderly patients who were referred to our psychogeriatric outpatient service were recruited. The severity of mental illness was evaluated by means of the Clinical Global Impression Severity scale, the severity of psychopathology was evaluated by means of the Brief Psychiatric Rating Scale (BPRS), and overall functioning was evaluated by means of the Global Assessment of Functioning scale. The sample included 73 (50.6%) patients with PPDs, 40 (27.8%) patients with MBI, and 31 (21.5%) patients with MNDs. Patients with MNDs reported the greatest severity of mental illness, the highest BPRS Total, Psychosis, Activation, and Negative Symptom scores, and the lowest functioning. Patients with MBI and PPDs had comparable levels of severity of mental illness and overall functioning, but MBI patients reported higher BPRS Total and Negative Symptom scores than PPD patients. Patients with MBI frequently reported specific clinical features, including a higher severity of apathy and motor retardation. These features merit further investigation since they may help the differential diagnosis between MBI and PPDs.

Structural neuroimaging phenotypes of a novel multi-gene risk score in youth bipolar disorder

BACKGROUND

Bipolar disorder (BD) is among the most heritable psychiatric disorders, particularly in early-onset cases, owing to multiple genes of small effect. Here we examine a multi-gene risk score (MGRS), to address the gap in multi-gene research in early-onset BD.

METHODS

MGRS was derived from 34 genetic variants relevant to neuropsychiatric diseases and related systemic processes. Multiple MGRS were calculated across a spectrum of inclusion p-value thresholds, based on allelic associations with BD. Youth participants (123 BD, 103 healthy control [HC]) of European descent were included, of which 101 participants (58 BD, 43 HC) underwent MRI T1-weighted structural neuroimaging. Hierarchical regressions examined for main effects and MGRS-by-diagnosis interaction effects on 6 regions-of-interest (ROIs). Vertex-wise analysis also examined MGRS-by-diagnosis interactions.

RESULTS

MGRS based on allelic association p≤0.60 was most robust, explaining 6.8% of variance (t(226)=3.46, p=.001). There was an MGRS-by-diagnosis interaction effect on ventrolateral prefrontal cortex surface area (vlPFC; β=.21, p=.0007). Higher MGRS was associated with larger vlPFC surface area in BD vs. HC. There were 8 significant clusters in vertex-wise analyses, primarily in fronto-temporal regions, including vlPFC.

LIMITATIONS

Cross-sectional design, modest sample size.

CONCLUSIONS

There was a diagnosis-by-MGRS interaction effect on vlPFC surface area, a region involved in emotional processing, emotional regulation, and reward response. Vertex-wise analysis also identified several clusters overlapping this region. This preliminary study provides an example of an approach to imaging-genetics that is intermediate between candidate gene and genome-wide association studies, enriched for genetic variants with established relevance to neuropsychiatric diseases.

Proof-of-concept study of a multi-gene risk score in adolescent bipolar disorder

BACKGROUND

Few studies have examined multiple genetic variants concurrently for the purpose of classifying bipolar disorder (BD); the literature among youth is particularly sparse. We selected 35 genetic variants, previously implicated in BD or associated characteristics, from which to identify the most robustly predictive group of genes.

METHODS

215 Caucasian adolescents (114 BD and 101 healthy controls (HC), ages 13-20 years) were included. Psychiatric diagnoses were determined based on semi-structured diagnostic interviews. Genomic DNA was extracted from saliva for genotyping. Two models were used to calculate a multi-gene risk score (MGRS). Model 1 used forward and backward regressions, and model 2 used a PLINK generated method.

RESULTS

In model 1, GPX3 rs3792797 was significant in the forward regression, DRD4 exonIII was significant in the backward regression; IL1β rs16944 and DISC1 rs821577 were significant in both the forward and backward regressions. These variants are involved in dopamine neurotransmission; inflammation and oxidative stress; and neuronal development. Model 1 MGRS did not significantly discriminate between BD and HC. In model 2, ZNF804A rs1344706 was significantly associated with BD; however, this association did not predict diagnosis when entered into the weighted model.

LIMITATIONS

This study was limited by the number of genetic variants examined and the modest sample size.

CONCLUSIONS

Whereas regression approaches identified four genetic variants that significantly discriminated between BD and HC, those same variants no longer discriminated between BD and HC when computed as a MGRS. Future larger studies are needed evaluating intermediate phenotypes such as neuroimaging and blood-based biomarkers.

Prediction of Response to Drug Therapy in Psychiatric Disorders

Reprinted with permission from Open Biol. 8: 180031. The Royal Society.

Prediction of response to drug therapy in psychiatric disorders

Personalized medicine has become increasingly relevant to many medical fields, promising more efficient drug therapies and earlier intervention. The development of personalized medicine is coupled with the identification of biomarkers and classification algorithms that help predict the responses of different patients to different drugs. In the last 10 years, the Food and Drug Administration (FDA) has approved several genetically pre-screened drugs labelled as pharmacogenomics in the fields of oncology, pulmonary medicine, gastroenterology, haematology, neurology, rheumatology and even psychiatry. Clinicians have long cautioned that what may appear to be similar patient-reported symptoms may actually arise from different biological causes. With growing populations being diagnosed with different psychiatric conditions, it is critical for scientists and clinicians to develop precision medication tailored to individual conditions. Genome-wide association studies have highlighted the complicated nature of psychiatric disorders such as schizophrenia, bipolar disorder, major depression and autism spectrum disorder. Following these studies, association studies are needed to look for genomic markers of responsiveness to available drugs of individual patients within the population of a specific disorder. In addition to GWAS, the advent of new technologies such as brain imaging, cell reprogramming, sequencing and gene editing has given us the opportunity to look for more biomarkers that characterize a therapeutic response to a drug and to use all these biomarkers for determining treatment options. In this review, we discuss studies that were performed to find biomarkers of responsiveness to different available drugs for four brain disorders: bipolar disorder, schizophrenia, major depression and autism spectrum disorder. We provide recommendations for using an integrated method that will use available techniques for a better prediction of the most suitable drug.

Efficacy and tolerability of lithium for the treatment of acute mania in children with bipolar disorder: A systematic review: A report from the ISBD-IGSLi joint task force on lithium treatment

OBJECTIVES

To assess the efficacy and tolerability of lithium for the treatment of acute mania in children and adolescent diagnosed with bipolar disorder.

METHODS

A systematic literature search up to August 2017 was conducted for clinical trials that included lithium in males and females up to 18 years of age with a diagnosis of bipolar disorder and experiencing a manic or mixed episode according to standardized diagnostic criteria. The protocol was registered in PROSPERO (CRD42017055675).

RESULTS

Four independent studies described in seven manuscripts met the inclusion criteria. Overall, 176 patients were treated with lithium either as a monotherapy or adjunct to risperidone. Efficacy results suggest that lithium may be superior to placebo (standardized mean difference [SMD] -0.42, 95% confidence interval [CI] -0.88 to 0.04), comparable to sodium divalproex (SMD -0.07, 95% CI: -0.31 to 0.18), but significantly less effective than risperidone for treating protracted manic/mixed episodes and comorbid attention-deficit hyperactivity disorder (ADHD) in prepubertal children (SMD 0.85, 95% CI: 0.54 to 1.15). Lithium was not associated with serious adverse events, and was generally well tolerated with common side effects similar to those reported in adults.

CONCLUSIONS

Limited data suggests that lithium may be an effective and tolerable treatment for some forms of paediatric mania. However, lithium is clearly inferior in efficacy to risperidone in prepubertal patients diagnosed with protracted manic/mixed episodes and comorbid ADHD. There is a lack of data concerning the efficacy and tolerability of lithium as an acute treatment for classical mania in adolescents and important clinical issues remain unaddressed.

Safety and efficacy of lithium in children and adolescents: A systematic review in bipolar illness

Introduction:

Many clinicians are reluctant to use traditional mood-stabilizing agents, especially lithium, in children and adolescents. This review examined the evidence for lithium’s safety and efficacy in this population.

Methods:

A systematic review was conducted on the use of lithium in children and adolescents with bipolar disorder (BD). Relevant papers published through June 30th 2018 were identified searching the electronic databases MEDLINE, Embase, PsycINFO and the Cochrane Library.

Results:

30 articles met inclusion criteria, including 12 randomized controlled trials (RCTs). Findings from RCTs demonstrate efficacy for acute mania in up to 50% of patients, and evidence of long-term maintenance efficacy. Lithium was generally safe, at least in the short term, with most common side effects being gastrointestinal, polyuria, or headache. Only a minority of patients experienced hypothyroidism. No cases of acute kidney injury or chronic kidney disease were reported.

Conclusions:

Though the available literature is mostly short-term, there is evidence that lithium monotherapy is reasonably safe and effective in children and adolescents, specifically for acute mania and for prevention of mood episodes.

Alterations of Intrinsic Brain Connectivity Patterns in Depression and Bipolar Disorders: A Critical Assessment of Magnetoencephalography-Based Evidence

Despite being the object of a thriving field of clinical research, the investigation of intrinsic brain network alterations in psychiatric illnesses is still in its early days. Because the pathological alterations are predominantly probed using functional magnetic resonance imaging (fMRI), many questions about the electrophysiological bases of resting-state alterations in psychiatric disorders, particularly among mood disorder patients, remain unanswered. Alongside important research using electroencephalography (EEG), the specific recent contributions and future promise of magnetoencephalography (MEG) in this field are not fully recognized and valued. Here, we provide a critical review of recent findings from MEG resting-state connectivity within major depressive disorder (MDD) and bipolar disorder (BD). The clinical MEG resting-state results are compared with those previously reported with fMRI and EEG. Taken together, MEG appears to be a promising but still critically underexploited technique to unravel the neurophysiological mechanisms that mediate abnormal (both hyper- and hypo-) connectivity patterns involved in MDD and BD. In particular, a major strength of MEG is its ability to provide source-space estimations of neuromagnetic long-range rhythmic synchronization at various frequencies (i.e., oscillatory coupling). The reviewed literature highlights the relevance of probing local and interregional rhythmic synchronization to explore the pathophysiological underpinnings of each disorder. However, before we can fully take advantage of MEG connectivity analyses in psychiatry, several limitations inherent to MEG connectivity analyses need to be understood and taken into account. Thus, we also discuss current methodological challenges and outline paths for future research. MEG resting-state studies provide an important window onto perturbed spontaneous oscillatory brain networks and hence supply an important complement to fMRI-based resting-state measurements in psychiatric populations.

Meta-Analysis of the COMT Val158Met Polymorphism in Major Depressive Disorder: Effect of Ethnicity

The COMT (catechol-O-methyltransferase) Val158Met polymorphism (rs4680) is a potential susceptibility variant for major depressive disorder (MDD). Although many genetic studies have examined the association between MDD and this polymorphism, the results were inconclusive. In the present study, we conducted a series of meta-analyses of samples consisting of 2905 MDD cases and 2403 controls with the goal of determining whether this variant indeed has any effect on MDD. We revealed a significant association in the comparison of Val/Val + Val/Met vs. Met/Met (OR =1.180; 95 % CI = 1.019, 1.367; P = 0.027), Val/Met vs. Val/Val (OR =1.18; 95 % CI = 1.038, 1.361; P = 0.013), and Val/Met vs. Met/Met (OR =1.229; 95 % CI = 1.053, 1.435; P = 0.009). Further meta-analyses of samples with European ancestry demonstrated a significant association of this SNP with MDD susceptibility in Val/Val + Val/Met vs. Met/Met (OR =1.231, 95 % CI = 1.046, 1.449; P = 0.013) and Val/Met vs. Met/Met (OR =1.284, 95 % CI = 1.050, 1.484; P = 0.012). For the samples with East Asian ancestry, we found a significant association in both allelic (Val vs. Met: OR =0.835; 95 % CI = 0.714, 0.975; P = 0.023) and genotypic (Met/Met + Val/Met vs. Val/Val: OR =1.431, 95 % CI = 1.143, 1.791; P = 0.002; Val/Met vs. Val/Val: OR =1.482, 95 % CI = 1.171, 1.871; P = 0.001) analyses. No evidence of heterogeneity among studies or publication bias was observed. Together, our results indicate that the COMT Val158Met polymorphism is a vulnerability factor for MDD with distinct effects in different ethnic populations.

Interaction between SLC6A4 promoter variants and childhood trauma on the age at onset of bipolar disorders

Age at onset (AAO) of bipolar disorders (BD) could be influenced both by a repeat length polymorphism (5HTTLPR) in the promoter region of the serotonin transporter gene (SLC6A4) and exposure to childhood trauma. We assessed 308 euthymic patients with BD for the AAO of their first mood episode and childhood trauma. Patients were genotyped for the 5HTTLPR (long/short variant) and the rs25531. Genotypes were classified on functional significance (LL, LS, SS). A sample of 126 Brazilian euthymic patients with BD was used for replication. In the French sample, the correlation between AAO and trauma score was observed only among 'SS' homozygotes (p = 0.002) but not among 'L' allele carriers. A history of at least one trauma decreased the AAO only in 'SS' homozygotes (p = 0.001). These results remained significant after correction using FDR. Regression models suggested an interaction between emotional neglect and 'SS' genotype on the AAO (p = 0.009) and no further interaction with other trauma subtypes. Partial replication was obtained in the Brazilian sample, showing an interaction between emotional abuse and 'LS' genotype on the AAO (p = 0.02). In conclusion, an effect of childhood trauma on AAO of BD was observed only in patients who carry a specific stress responsiveness-related SLC6A4 promoter genotype.

Course and outcome following a first episode of mania: four-year prospective data from the Systematic Treatment Optimization Program (STOP-EM)

BACKGROUND

First episode mania (FEM) cohorts provide an opportunity to identify windows for intervention to potentially alter the course of bipolar disorder (BD). Despite several efforts to prospectively characterize first episode patients, follow-up of such cohorts has seldom exceeded 1 year. We present 4-year outcomes from the STOP-EM FEM cohort.

METHOD

Of 101 identified FEM patients, 81 had longitudinal follow-up. Clinical evaluations including substance misuse, sociodemographics and family history were characterized using semi-structured instruments. Clinical reassessments occurred every 6 months.

RESULTS

Within one year, all patients had remitted and 95% recovered. Recurrence following remission occurred in 58% of patients by 1 year and 74% by 4 years (60% depressive, 28% manic and 12% hypomanic). Recurrence within one year was associated with a higher rate of recurrence thereafter. Older age was associated with a shorter time to remission. Substance misuse was associated with delayed recovery and earlier recurrence.

LIMITATIONS

This prospective multiwave longitudinal design employed may be limited by the assessment schedule and associated recall bias. The influences of attrition of this sample should be considered when attempting to generalize our findings.

CONCLUSIONS

Best practices in FEM result in remission and recovery. While recurrence is common, minimizing recurrence within the first year through risk factor modification may alter the course of the BD.

Aquatic blues: modeling depression and antidepressant action in zebrafish

Depression is a serious psychiatric condition affecting millions of patients worldwide. Unipolar depression is characterized by low mood, anhedonia, social withdrawal and other severely debilitating psychiatric symptoms. Bipolar disorder manifests in alternating depressed mood and 'hyperactive' manic/hypomanic states. Animal experimental models are an invaluable tool for research into the pathogenesis of bipolar/unipolar depression, and for the development of potential treatments. Due to their high throughput value, genetic tractability, low cost and quick reproductive cycle, zebrafish (Danio rerio) have emerged as a promising new model species for studying brain disorders. Here, we discuss the developing utility of zebrafish for studying depression disorders, and outline future areas of research in this field. We argue that zebrafish represent a useful model organism for studying depression and its behavioral, genetic and physiological mechanisms, as well as for anti-depressant drug discovery.

A direct, controlled, blind family study of DSM-IV pathological gambling

OBJECTIVE

Pathological gambling is a major public health problem. We sought to examine the familiality of pathological gambling and determine patterns of familial aggregation of disorders.

METHOD

We assessed probands with DSM-IV pathological gambling, controls, and their first-degree relatives. Detailed family history information was collected on relatives who were deceased or unavailable.

RESULTS

Ninety-five pathological gambling probands, 91 controls, and their 1,075 first-degree relatives over age 18 (537 relatives of pathological gambling probands, 538 relatives of controls) were evaluated between February 2005 and June 2010. Relatives were assessed blind to proband status. Best estimate diagnoses were assigned. Rates of lifetime pathological gambling (definite/probable) was significantly greater among the first-degree relatives of probands with pathological gambling than among comparison relatives (11% vs 1%, OR = 8.19, P < .001). The prevalence of pathological gambling and subclinical pathological gambling combined was 16% and 3% in case and control relatives, respectively (OR = 6.57, P < .001). Pathological gambling relatives had higher rates of major depression (OR = 1.49, P < .05), bipolar disorder (OR = 3.82, P < .05), any mood disorder (OR = 1.59, P < .05), social anxiety disorder (OR = 4.76, P < .01), any substance use disorder (OR = 1.47, P < .05), posttraumatic stress disorder (OR = 2.59, P < .05), and antisocial personality disorder (OR = 3.72, P < .001). Antisocial personality disorder (OR = 3.12, P < .01), social anxiety disorder (OR = 4.15, P < .01), and posttraumatic stress disorder (OR = 2.85, P < .05) were more frequent in case relatives independent of the presence of pathological gambling. Age at onset of pathological gambling in case probands (< 40 years/≥ 40 years) was not related to familiality in their first-degree relatives (OR = 1.03, P = .927).

CONCLUSIONS

Pathological gambling is familial. Mood and substance use disorders may emerge as a consequence of the pathological gambling or as a more complex syndrome. In contrast, antisocial personality disorder, social anxiety disorder, and posttraumatic stress disorder may share a common familial etiology with pathological gambling. The phenotype may extend beyond pathological gambling to include subclinical forms of the disorder.

Molecular actions and clinical pharmacogenetics of lithium therapy

Mood disorders, including bipolar disorder and depression, are relatively common human diseases for which pharmacological treatment options are often not optimal. Among existing pharmacological agents and mood stabilizers used for the treatment of mood disorders, lithium has a unique clinical profile. Lithium has efficacy in the treatment of bipolar disorder generally, and in particular mania, while also being useful in the adjunct treatment of refractory depression. In addition to antimanic and adjunct antidepressant efficacy, lithium is also proven effective in the reduction of suicide and suicidal behaviors. However, only a subset of patients manifests beneficial responses to lithium therapy and the underlying genetic factors of response are not exactly known. Here we discuss preclinical research suggesting mechanisms likely to underlie lithium's therapeutic actions including direct targets inositol monophosphatase and glycogen synthase kinase-3 (GSK-3) among others, as well as indirect actions including modulation of neurotrophic and neurotransmitter systems and circadian function. We follow with a discussion of current knowledge related to the pharmacogenetic underpinnings of effective lithium therapy in patients within this context. Progress in elucidation of genetic factors that may be involved in human response to lithium pharmacology has been slow, and there is still limited conclusive evidence for the role of a particular genetic factor. However, the development of new approaches such as genome-wide association studies (GWAS), and increased use of genetic testing and improved identification of mood disorder patients sub-groups will lead to improved elucidation of relevant genetic factors in the future.

Divalproex sodium in the treatment of pediatric psychiatric disorders

Divalproex sodium is an anticonvulsant that is used extensively in adults with indications for epilepsy, acute mania and migraine prophylaxis. It has been used in children and adolescents as a first-line agent for mania in bipolar disorder. Its efficacy as a mood stabilizer has been established, and there have been studies outlining its efficacy as an agent effective in the treatment of conduct disorder, disruptive behavior disorders, aggression and explosive disorder. Longer-acting formulations are now available that cause less gastrointestinal side effects and can also be taken once a day, thus potentially increasing adherence, an important factor in this patient population. Future directions would include developing a more potent valproic acid formulation with fewer side effects, completing randomized controlled trials to establish the efficacy of divalproex sodium in various other pediatric psychiatric disorders, establishing the relative efficacy of the compound in head-to-head comparisons with other mood stabilizers, examining systematically the value of the compound in multimodal pediatric psychiatric treatment packages, and complete effectiveness trials that demonstrate the short- and long-term effectiveness of the compound in the real world of clinicians. In this drug profile, divalproex sodium and its uses in the pediatric population for psychiatric conditions are reviewed.

[Predicting bipolar disorder: what can we learn from prospective cohort studies?]

INTRODUCTION

Bipolar disorder (BD) is a life course illness; and there is increasing awareness of the many personal, social and economic consequences of the illness in older adults. However, it is important to emphasize that BD usually begins in late adolescence or early adulthood and 75 % cases have a first episode in this age period. This early onset and the associated level of disability mean that BD is the 4th leading cause of global disease burden in adolescents and young adults. Internationally, mental health services are increasingly striving to diagnose and treat BD as early as possible to try to prevent poor outcomes. In addition, researchers are using methods employed previously in psychosis studies as these may help us to recognise the earliest manifestations of BD. If it is possible to identify sub-threshold and 'ultra high risk' syndromes for BD, this might lead to new interventions that could target the prevention of first episodes of mania. One approach to understanding these risk syndromes is to examine prospective community cohort studies and BD offspring studies.

METHODS

This paper reviews prospective cohort studies that identify robust risk factors in early illness onset, which was defined as age at onset of BD between 15-25 years.

RESULTS

We found that although > 50 % of individuals who developed BD had developed a putative BD prodrome prior to 14 years of age, this usually began with non-specific symptoms that overlap with similar presentations for those who later develop psychosis or severe depression. However, there are some features that seem to better identify groups with a BD "at-risk" syndrome. This syndrome is frequently composed of several factors such as mood lability, depressive episodes, prior anxiety, sleep and/or conduct disorders, attention and concentration impairment, altered energy patterns, and a family history of mania and/or depression. The course of these early predictors suggests the precursor syndromes are composed of mini-clusters of symptoms many of which are episodic and change over time. During the early phases of BD, most of the affective disturbances reported were depressive in polarity and started during adolescence, there were few manic or mixed or psychotic episodes with an onset before puberty. The pathogenesis of BD demonstrates a gradual progression from non-specific to more specific symptoms and then to frank BD features.

CONCLUSION

Prospective community and offspring BD cohort studies are approaches that together can help us understand the evolution of BD and allow us to define the developmental pathways. Further, identifying subjects with BD "at-risk" syndrome using a clinical staging model may allow benign interventions to be used as first-line treatment - such as neuroprotective agents like essential fatty acids; second line treatments, with a less benign risk to benefit ratio should be reserved for severe or resistant cases.

Characteristics and profiles of bipolar I patients according to age-at-onset: findings from an admixture analysis

BACKGROUND

Many studies have used admixture analysis to separate age-at-onset (AAO) subgroups in bipolar patients, but few have looked at the phenomenological characteristics of these subgroups, in order to find out phenotypic markers.

METHODS

Admixture analysis was applied to identify the model best fitting the observed AAO distribution of a sample of 1082 consecutive DSM-IV bipolar I manic inpatients who were assessed for demographic, clinical, course of illness, comorbidity, and temperamental characteristics.

RESULTS

The model best fitting the observed distribution of AAO was a mixture of three Gaussian distributions. We could identify three AAO subgroups: early, intermediate, and late age-at-onset (EAO, IAO, and LAO, respectively). Patients in the EAO subgroup were more often single young males exhibiting severe mania with psychotic features, a subcontinuous course of illness with substance use and panic comorbidity, more suicide attempts, and temperamental components sharing hypomanic features. Patients with LAO showed a less severe picture with more depressive temperamental components, alcohol use and comorbid general medical conditions. A less typical phenotype was present in IAO patients.

LIMITATIONS

The following are the limitations of this study: retrospective design, and bias toward preferential enrollment of patients with manic predominant polarity.

CONCLUSIONS

This study confirms that bipolar I disorder can be subdivided into three subgroups based on AAO distribution and shows that patients from these subgroups differ in phenotypes.

A three generations nation-wide population study of family load estimates in bipolar disorder with different age at onset

OBJECTIVES

This nation-wide register-based study investigates how often bipolar disorder (BD) occurs in affected families compared to control families by estimating the family load as a random effect; this effect measures the degree of dependence among family members in relation to BD. Furthermore, the study addresses the impact of certain risk factors, namely, sex, age at onset of BD, degree of urbanization, year of birth, month of birth, and maternal and paternal age at birth.

METHOD

A total of N=1204 children and adolescent psychiatric cases born between 1950 and 1997 and registered in the Danish Central Psychiatric Register (DPCR) developed BD before the age of 58 years. N=3553 controls without any psychiatric diagnosis were matched for age, gender, and region of residence. Psychiatric diagnoses were also obtained on the relatives, e.g. parents, siblings, and offspring as a part of the Danish Three Generation Study (3GS). A family component was obtained by using different regression models.

RESULTS

Familial factors accounted for 20% of the variation in disease outcome when controlling for year and month of birth, sex, and degree of urbanization. Only female sex was associated with an increased hazard ratio of BD. Also having a mother, father or a sibling with the disorder was proven to be a significant risk factor. Furthermore, case relatives did not develop BD earlier than control relatives.

CONCLUSION

These findings based on a very large and representative dataset provide further and very solid evidence for the high family aggregation of BD.

Genetic risk of suicidal behavior in bipolar spectrum disorder: analysis of 737 pedigrees

OBJECTIVES

Suicide is a significant cause of mortality in patients with major affective disorders (MAD), and suicidal behavior and MAD co-aggregate in families. However, the transmission of suicidal behavior is partially independent from that of MAD. We analyzed the lifetime prevalence of completed and attempted suicides in a large sample of families with bipolar disorder (BD), its relation to family history of MAD and BD, and the contribution of clinical and treatment factors to the risk of suicidal behavior.

METHODS

We studied 737 families of probands with MAD with 4919 first-degree relatives (818 affected, 3948 unaffected, and 153 subjects with no information available). Lifetime psychiatric diagnoses and suicidal behavior in first-degree relatives were assessed using semi-structured interviews, family history methods, and reviews of clinical records. Cox proportional hazard and logistic regression models were used to investigate the role of clinical covariates in the risk of suicidal behavior, and in the prevalence of MAD and BD.

RESULTS

The estimated lifetime prevalence of suicidal behavior (attempted and completed suicides) in 737 probands was 38.4 ± 3.0%. Lithium treatment decreased suicide risk in probands (p = 0.007). In first-degree relatives, a family history of suicidal behavior contributed significantly to the joint risk of MAD and suicidal behavior (p = 0.0006).

CONCLUSIONS

The liability to suicidal behavior is influenced by genetic factors (particularly family history of suicidal behavior and MAD). Even in the presence of high genetic risk for suicidal behavior, lithium treatment decreases suicide rates significantly.

Hypomania spectrum disorders from adolescence to adulthood: a 15-year follow-up of a community sample

BACKGROUND

There is a lack of scientific knowledge about the broader spectrum of hypomania in adolescence and the course over time. To investigate this, we used longitudinal data spanning from adolescence to age 31 years.

METHOD

A community sample of adolescents (N=2300) was screened for depressive symptoms. Adolescents (16-17 years) with a positive screening and matched controls were interviewed with a structured diagnostic interview. A blinded follow-up assessment was conducted 15 years later, with a structured diagnostic interview covering the age span 19-31 years. Questions about treatment and family history were included.

RESULTS

Ninety adolescents (16-17 years) with a lifetime hypomania spectrum episode (3.9% of the total sample) were identified: 40 with fullsyndromal, 18 with brief-episode (<4 day), and 32 with subsyndromal (1-2 main symptoms and 1-2 additional symptoms) hypomania. The hypomania symptoms reported by the fullsyndromal and the brief-episode groups were similar, whereas the subsyndromal group per definition reported fewer symptoms. Of the 90 adolescents with a hypomania spectrum episode, 64 (71%) participated in the follow-up interview. Mania in adulthood was reported by 2 (3%), hypomania by an additional 4 (6%), and major depression by 38 (59%). Incidence of mood episodes in adulthood did not differ between the subgroups of hypomania spectrum.

LIMITATIONS

29% of the participants with hypomania spectrum were lost to follow-up.

CONCLUSION

The results indicate that only a small proportion of adolescents with hypomania spectrum episodes continue to have (hypo)mania in adulthood. Thus, maintenance or prophylactic treatment does not seem warranted for this group.

Further evidence that pediatric-onset bipolar disorder comorbid with ADHD represents a distinct subtype: results from a large controlled family study

We used familial risk analysis to clarify the diagnostic comorbidity between pediatric BP-I disorder and ADHD, testing the hypothesis that pediatric-BP-I disorder comorbid with ADHD represents a distinct subtype. Structured diagnostic interviews were used to obtain DSM-IV psychiatric diagnoses on first-degree relatives (n = 726) of referred children and adolescents satisfying diagnostic criteria for BP-I disorder (n = 239). For comparison, diagnostic information on the first-degree relatives (N = 511) of non-bipolar ADHD children (N = 162) and the first degree relatives (N = 411) of control children (N = 136) with neither ADHD nor BP-I disorder were examined. BP-I disorder and ADHD in probands bred true irrespective of the comorbidity with the other disorder. We also found that the comorbid condition of BP-I disorder plus ADHD also bred true in families, and the two disorders co-segregated among relatives. This large familial risk analysis provides compelling evidence that pediatric BP-I disorder comorbid with ADHD represents a distinct familial subtype.

Pharmacologic treatment of bipolar disorder in children and adolescents

This review focuses mainly on published articles regarding the treatment of school-aged children and adolescents with pediatric bipolar disorder. In light of systematic reviews, large randomized controlled trial data are emphasized wherever possible. This review addresses the treatment of acute manic/mixed episodes, including combination treatment, the preliminary literature regarding bipolar depression among youth, treatment in the face of comorbid conditions, and maintenance treatment. Suggestions regarding future directions are offered. A clinical vignette describing a teen with bipolar disorder is presented and bipolar medications, dosing, efficacy, side effects, contraindications, and succinct comments on each medication are summarized.

Genome-wide survey implicates the influence of copy number variants (CNVs) in the development of early-onset bipolar disorder

We used genome-wide single nucleotide polymorphism (SNP) data to search for the presence of copy number variants (CNVs) in 882 patients with bipolar disorder (BD) and 872 population-based controls. A total of 291 (33%) patients had an early age-at-onset < or =21 years (AO < or =21 years). We systematically filtered for CNVs that cover at least 30 consecutive SNPs and which directly affect at least one RefSeq gene. We tested whether (a) the genome-wide burden of these filtered CNVs differed between patients and controls and whether (b) the frequency of specific CNVs differed between patients and controls. Genome-wide burden analyses revealed that the frequency and size of CNVs did not differ substantially between the total samples of BD patients and controls. However, separate analysis of patients with AO < or =21 years and AO>21 years showed that the frequency of microduplications was significantly higher (P=0.0004) and the average size of singleton microdeletions was significantly larger (P=0.0056) in patients with AO < or =21 years compared with controls. A search for specific BD-associated CNVs identified two common CNVs: (a) a 160 kb microduplication on 10q11 was overrepresented in AO < or = 21 years patients (9.62%) compared with controls (3.67%, P=0.0005) and (b) a 248 kb microduplication on 6q27 was overrepresented in the AO< or = 21 years subgroup (5.84%) compared with controls (2.52%, P=0.0039). These data suggest that CNVs have an influence on the development of early-onset, but not later-onset BD. Our study provides further support for previous hypotheses of an etiological difference between early-onset and later-onset BD.

Brief report: a family risk study exploring bipolar spectrum problems and cognitive biases in adolescent children of bipolar parents

Children of parents with bipolar disorder are at increased risk of bipolar spectrum diagnoses. This cross-sectional study explores cognitive factors in the prediction of vulnerability to bipolar disorder. Adolescents at high-risk (with a parent with bipolar disorder; n = 23) and age and gender matched adolescents (n = 24) were recruited. Parent and adolescent diagnoses were evaluated (SCID and SADS-L). Adolescents completed self-report measures assessing attributional style (ASQ), appraisal of hypomania-relevant experiences (HIQ), and hypomanic personality/temperament (HPS). Despite limitations in the power of the study, significantly more adolescents at high-risk for disorder received bipolar spectrum diagnoses. Groups did not differ in attributional style, hypomanic temperament or appraisals of hypomania-relevant experiences. A trend in ASQ results and general implications are discussed. The current study suggests that familial risk of bipolar disorder is not inevitably associated with cognitive biases in adolescence.

Circadian biomarkers, circadian genes and bipolar disorders

Bipolar disorders are associated with circadian deregulations both during acute mood episodes and during euthymic periods, suggesting that these circadian rhythms may represent trait markers of the disease. Several arguments demonstrate that deregulations of circadian rhythms may be part of the pathophysiology of bipolar disorders. Abnormal quantitative and qualitative circadian disturbances have been repeatedly showed in bipolar patients, both during euthymic periods and acute phases, using different assessment tools such as actigraphy, polysomnography, and blood melatonin monitoring. In addition, many circadian physiological functions have been demonstrated to be altered in bipolar patients, such as secretion of hormones and other endogenous substances, core temperature, and fibroblasts activity. Furthermore, mood stabilizers efficiency could partially be explained by their impact on the regulation of the circadian rhythms. The implication of genetic vulnerability factors has long been demonstrated in bipolar disorders and several circadian genes have been tested for association in bipolar disorders. Although preliminary, interesting results have been obtained in several independent studies.

Admixture analysis of age at onset in bipolar disorder

The aim of this study was to identify whether age at onset (AAO) identifies Bipolar Disorder (BD) subtypes, and to test whether the subgroups were confirmed by different clinical profiles. Admixture analysis was applied to determine a model that best fit the observed distribution of AAO in 964 BD patients. Three distributions of AAO were identified, and age means were 16.1 (S.D. 4.2), 25.4 (S.D. 2.5) and 32.2 (S.D. 9.5) years. A significant increased rate of suicide attempts, Bipolar I (BD I) caseness, and depressive onset was observed in the early-onset group when compared to those with later-onset by means of χ². Findings from extant studies and our results are remarkably consistent in showing that BD can be subdivided into three groups based on AAO distributions, and that early-onset is associated with higher rates of suicide attempts.

The representation of early onset depression by ICD-9 and ICD-10 categories

BACKGROUND

Concepts of affective disorders have not received substantial validation in childhood and adolescence even after the theoretical separation between neurotic and endogenous depression was changed. The aim of this study was to assess differences in children and adolescents with neurotic and endogenous depression according to ICD-9 and depression according to ICD-10 with regard to the severity of different symptoms as well as anamnestic and psychosocial risk factors.

SAMPLING AND METHODS

Data of 33 and 88 patients (classified according to ICD-9 and ICD-10, respectively) with a confirmed diagnosis of depression were included. In a standardized study protocol, sociodemographic data, family history, psychopathological symptoms and psychosocial and environmental factors were analyzed.

RESULTS

Patients diagnosed with endogenous depression more frequently had a positive family history of psychiatric disorders and had more comorbid symptoms in comparison to those with neurotic depression. Group comparisons of the ICD-9 and ICD-10 demonstrated fewer abnormal psychosocial and environmental factors and fewer affective symptoms in the ICD-9 sample. Logistic regression revealed predictors for endogenous depression in the ICD-9 sample and severe depression in the ICD-10 sample.

CONCLUSIONS

Neurotic depression might represent a subthreshold depression diagnosis compared with endogenous depression. The present study was limited by small and different sample sizes and the fact that dysthymia was not classified within the ICD-10 diagnosis.

Subthreshold hypomanic symptoms in progression from unipolar major depression to bipolar disorder

OBJECTIVE

The authors assessed whether subthreshold hypomanic symptoms in patients with major depression predicted new-onset mania or hypomania.

METHOD

The authors identified 550 individuals followed for at least 1 year in the National Institute of Mental Health Collaborative Depression Study with a diagnosis of major depression at intake. All participants were screened at baseline for five manic symptoms: elevated mood, decreased need for sleep, unusually high energy, increased goal-directed activity, and grandiosity. Participants were followed prospectively for a mean of 17.5 years and up to 31 years. The Longitudinal Interval Follow-up Examination was used to monitor course of illness and to identify any hypomania or mania. The association of subthreshold hypomanic symptoms at baseline with subsequent hypomania or mania was determined in survival analyses using Cox proportional hazards regression.

RESULTS

With a cumulative probability of one in four on survival analysis, 19.6% (N=108) of the sample experienced hypomania or mania, resulting in revision of diagnoses for 12.2% to bipolar II disorder and 7.5% to bipolar I disorder. Number of subthreshold hypomanic symptoms, presence of psychosis, and age at illness onset predicted progression to bipolar disorder. Decreased need for sleep, unusually high energy, and increased goal-directed activity were specifically implicated.

CONCLUSIONS

Symptoms of hypomania, even when of low intensity, were frequently associated with subsequent progression to bipolar disorder, although the majority of patients who converted did not have any symptoms of hypomania at baseline. These results suggest that continued monitoring for the possibility of progression to bipolar disorder is necessary over the long-term course of major depressive disorder.

Preventative strategies for early-onset bipolar disorder: towards a clinical staging model

Bipolar disorder is a chronic and typically recurring illness with significant psychosocial morbidity. Although the aetiological factors that contribute to the onset of mania, and by definition bipolar I disorder, are poorly understood, it most commonly occurs during the adolescent period. Putative risk factors for developing bipolar disorder include having a first-degree relative with a mood disorder, physical/sexual abuse and other psychosocial stressors, substance use disorders, psychostimulant and antidepressant medication exposure and omega-3 fatty acid deficiency. Prominent prodromal clinical features include episodic symptoms of depression, anxiety, hypomania, anger/irritability and disturbances in sleep and attention. Because prodromal mood symptoms precede the onset of mania by an average of 10 years, and there is low specificity of risk factors and prodromal features for mania, interventions initiated prior to onset of the disorder (primary prevention) or early in the course of the disorder (early or secondary prevention) must be safe and well tolerated upon long-term exposure. Indeed, antidepressant and psychostimulant medications may precipitate the onset of mania. Although mood stabilizers and atypical antipsychotic medications exhibit efficacy in youth with bipolar I disorder, their efficacy for the treatment of prodromal mood symptoms is largely unknown. Moreover, mood stabilizers and atypical antipsychotics are associated with prohibitive treatment-emergent adverse effects. In contrast, omega-3 fatty acids have neurotrophic and neuroprotective properties and have been found to be efficacious, safe and well tolerated in the treatment of manic and depressive symptoms in children and adolescents. Together, extant evidence endorses a clinical staging model in which subjects at elevated risk for developing mania are treated with safer interventions (i.e. omega-3 fatty acids, family-focused therapy) in the prodromal phase, followed by pharmacological agents with potential adverse effects for nonresponsive cases and secondary prevention. This approach warrants evaluation in prospective longitudinal trials in youth determined to be at ultra-high risk for bipolar I disorder.

Association between age of onset and mood in bipolar disorder: comparison of subgroups identified by cluster analysis and clinical observation

BACKGROUND

This study compared subgroups identified by cluster analysis and clinical observation by evaluating the association between the age of onset of bipolar disorder and self-reported daily mood ratings.

METHODS

Two hundred and seventy patients with bipolar disorder provided daily self-reported mood ratings for about 6 months returning 55,188 days of data. The age of onset subgroups were determined both using previously defined cutoff values based upon clinical observation (≤12 years, 13-19 years, 20-29 years, >29 years), and model-based cluster analysis. Demographic characteristics were compared in the age of onset subgroups. Univariate general linear models with age of onset subgroups and other demographic variables as fixed factors and covariates were used to analyze the percent of days depressed, euthymic and hypomanic/manic.

RESULTS

Using the predetermined subgroups, demographic differences were found between the four subgroups in the diagnosis of bipolar I/II, years of illness, age and use of lamotrigine. Post-hoc pairwise comparison found that patients with an age of onset less ≤ 12 years spent more days hypomanic/manic: 16.4 percent versus 8.0 for patients with an age of onset between 13 and 19 years (p=0.006) and 8.2 percent for patients with an age of onset between 20 and 29 years (p = 0.031). The majority of the additional days of hypomania/mania occurred outside of an episode. Model-based cluster analysis found a mixture of 2 distributions of onset with peaks at age 15.1 years (SD = 4.7) and 27.5 years (SD = 10.2). Analysis of these two subgroups detected no significant differences in demographic characteristics or mood ratings.

CONCLUSION

Age of onset subgroups arising from clinical observation may be more useful than those determined by cluster analysis.

A controlled family study of children with DSM-IV bipolar-I disorder and psychiatric co-morbidity

BACKGROUND

To estimate the spectrum of familial risk for psychopathology in first-degree relatives of children with unabridged DSM-IV bipolar-I disorder (BP-I).

METHOD

We conducted a blinded, controlled family study using structured diagnostic interviews of 157 children with BP-I probands (n=487 first-degree relatives), 162 attention deficit hyperactivity disorder (ADHD) (without BP-I) probands (n=511 first-degree relatives), and 136 healthy control (without ADHD or BP-I) probands (n=411 first-degree relatives).

RESULTS

The morbid risk (MR) of BP-I disorder in relatives of BP-I probands (MR=0.18) was increased 4-fold [95% confidence interval (CI) 2.3-6.9, p<0.001] over the risk to relatives of control probands (MR=0.05) and 3.5-fold (95% CI 2.1-5.8, p<0.001) over the risk to relatives of ADHD probands (MR=0.06). In addition, relatives of children with BP-I disorder had high rates of psychosis, major depression, multiple anxiety disorders, substance use disorders, ADHD and antisocial disorders compared with relatives of control probands. Only the effect for antisocial disorders lost significance after accounted for by the corresponding diagnosis in the proband. Familial rates of ADHD did not differ between ADHD and BP-I probands.

CONCLUSIONS

Our results document an increased familial risk for BP-I disorder in relatives of pediatric probands with DSM-IV BP-I. Relatives of probands with BP-I were also at increased risk for other psychiatric disorders frequently associated with pediatric BP-I. These results support the validity of the diagnosis of BP-I in children as defined by DSM-IV. More work is needed to better understand the nature of the association between these disorders in probands and relatives.

Correlation between amygdala volume and age in bipolar disorder - a systematic review and meta-analysis of structural MRI studies

The amygdala has gained special interest regarding the neuropathology of bipolar disorder (BD). Structural magnetic resonance imaging (MRI) studies with patients suffering from BD have yielded quite inconsistent results with respect to amygdala volume. We performed a meta-analysis of structural MRI studies that investigated right and left amygdala volume in pediatric and adult patients with BD. The aim was to assess the heterogeneous findings and to investigate whether a correlation between amygdala volume and the patient's age exists. Studies were searched for in "Pub Med" (last search June 2007), and data for right and left amygdala volume in cm(3) were extracted and combined in a meta-analysis. Thirteen studies with 389 scans of patients and 488 scans of healthy control subjects (HC) were included. The impact of age on the difference in amygdala volume between patients and HC was assessed by meta-regression. The amygdala volume was bilaterally reduced in the overall sample of patients with BD and the pediatric subsample. The results of the adult studies were less homogeneous, and on average, no significant difference between adult patients and HC was found. A meta-regression analysis revealed a positive correlation between mean age and amygdala volume in patients with BD. We speculate that amygdala volume is reduced at the onset of the disease and increases with age.

Lithium: a key to the genetics of bipolar disorder

Since the 1950s, lithium salts have been the main line of treatment for bipolar disorder (BD), both as a prophylactic and as an episodic treatment agent. Like many psychiatric conditions, BD is genetically and phenotypically heterogeneous, but evidence suggests that individuals who respond well to lithium treatment have more homogeneous clinical and molecular profiles. Response to lithium seems to cluster in families and can be used as a predictor for recurrence of BD symptoms. While molecular studies have provided important information about possible genes involved in BD predisposition or in lithium response, neither the mechanism of action of this drug nor the genetic profile of bipolar disorder is, as yet, completely understood.

The impact of age at onset of bipolar I disorder on functioning and clinical presentation

OBJECTIVES

Recent studies have proposed the existence of three distinct subgroups of bipolar 1 disorder based on age at onset (AAO). The present study aims to investigate potential clinical and functional differences between these subgroups in an Australian sample.

METHODS

Participants (n = 239) were enrolled in the Bipolar Comprehensive Outcomes Study (BCOS), a 2-year longitudinal, observational, cross-sectional study. Assessment measures included the Young Mania Rating Scale (YMRS), Hamilton Depression Rating Scale (HAMD21), Clinical Global Impressions Scale (CGI-BP), SF-36, SLICE/Life Scale, and the EuroQol (EQ-5D). Participants were also asked about their age at the first major affective episode.

RESULTS

Three AAO groups were compared: early (AAO < 20, mean = 15.5 ± 2.72; 44.4% of the participants); intermediate (AAO 20-39, mean = 26.1 ± 4.8; 48.14% of the participants) and late (AAO > 40, mean = 50.6 ± 9.04; 7.4% of the participants). Higher rates of depression, suicidal ideation and binge drinking were reported by the early AAO group. This group also reported poorer quality of life in a number of areas. The early AAO group had a predominant depressive initial polarity and the intermediate group had a manic predominance.

CONCLUSION

Early AAO is associated with an adverse outcome.

Neurocognitive impairment in unaffected siblings of youth with bipolar disorder

BACKGROUND

There is growing evidence for the familiality of pediatric bipolar disorder (BPD) and its association with impairments on measures of processing speed, verbal learning and 'executive' functions. The current study investigated whether these neurocognitive impairments index the familial risk underlying the diagnosis.

METHOD

Subjects were 170 youth with BPD (mean age 12.3 years), their 118 non-mood-disordered siblings and 79 non-mood-disordered controls. Groups were compared on a battery of neuropsychological tests from the Wechsler Intelligence Scales, the Stroop Color Word Test, the Wisconsin Card Sorting Test (WCST), the Rey-Osterrieth Complex Figure (ROCF), an auditory working memory Continuous Performance Test (CPT) and the California Verbal Learning Test-Children's Version (CVLT-C). Measures were factor analyzed for data reduction purposes. All analyses controlled for age, sex and attention-deficit/hyperactivity disorder (ADHD).

RESULTS

Principal components analyses with a promax rotation yielded three factors reflecting: (1) processing speed/verbal learning, (2) working memory/interference control and (3) abstract problem solving. The CPT working memory measure with interference filtering demands (WM INT) was only administered to subjects aged > or =12 years and was therefore analyzed separately. BPD youth showed impairments versus controls and unaffected relatives on all three factors and on the WM INT. Unaffected relatives exhibited impairments versus controls on the abstract problem-solving factor and the WM INT. They also showed a statistical trend (p=0.07) towards worse performance on the working memory/interference control factor.

CONCLUSIONS

Neurocognitive impairments in executive functions may reflect the familial neurobiological risk mechanisms underlying pediatric BPD and may have utility as endophenotypes in molecular genetic studies of the condition.

Genome scan in sibling pairs with juvenile-onset mood disorders: Evidence for linkage to 13q and Xq

Mood disorders (bipolar and depressive disorders) in children and adolescents are associated with significant morbidity and mortality. Twin and family studies, for the most part, indicate higher familiality and heritability for mood disorders that onset in childhood/adolescence than those that onset in adulthood. To identify the genetic contribution to mood disorders that onset in childhood/adolescence, we performed a genome scan on 146 nuclear families from Hungary containing an affected proband and affected siblings. In total, the pedigrees contained 303 affected children: 146 probands, 137 siblings with a first episode of mood disorder before 14.9 years of age, and 20 siblings with onset of their first episode after 14.9 years of age but before the age of 18. The results of the genome scan using 405 microsatellite markers did not provide evidence for linkage at the recommended genome wide significance level for any novel loci. However, markers on two chromosomes, 13q and Xq, provided evidence for linkage in regions previously identified as linked to bipolar disorder in multiple studies. For the marker on chromosome 13q the peak non-parametric multipoint LOD score was at the marker D13S779 (LOD = 1.5, P = 0.004). On chromosome Xq, evidence for linkage was observed across a large region spanning two regions previously linked to bipolar disorder; Xq24 to Xq28, with a peak at marker TTTA062 (LOD 2.10, P = 0.0009) in Xq28. Results for these regions exceed the recommended P-value for a replication study of P < 0.01 and thus provide evidence for these two loci as contributing to mood disorders with juvenile onset.

Four-year longitudinal course of children and adolescents with bipolar spectrum disorders: the Course and Outcome of Bipolar Youth (COBY) study

OBJECTIVE

The authors sought to assess the longitudinal course of youths with bipolar spectrum disorders over a 4-year period.

METHOD

At total of 413 youths (ages 7-17 years) with bipolar I disorder (N=244), bipolar II disorder (N=28), and bipolar disorder not otherwise specified (N=141) were enrolled in the study. Symptoms were ascertained retrospectively on average every 9.4 months for 4 years using the Longitudinal Interval Follow-Up Evaluation. Rates and time to recovery and recurrence and week-by-week symptomatic status were analyzed.

RESULTS

Approximately 2.5 years after onset of their index episode, 81.5% of the participants had fully recovered, but 1.5 years later 62.5% had a syndromal recurrence, particularly depression. One-third of the participants had one syndromal recurrence, and 30% had two or more. The polarity of the index episode predicted that of subsequent episodes. Participants were symptomatic during 60% of the follow-up period, particularly with subsyndromal symptoms of depression and mixed polarity, with numerous changes in mood polarity. Manic symptomatology, especially syndromal, was less frequent, and bipolar II was mainly manifested by depressive symptoms. Overall, 40% of the participants had syndromal or subsyndromal symptoms during 75% of the follow-up period, and 16% of the participants experienced psychotic symptoms during 17% the follow-up period. Twenty-five percent of youths with bipolar II converted to bipolar I, and 38% of those with bipolar disorder not otherwise specified converted to bipolar I or II. Early onset, diagnosis of bipolar disorder not otherwise specified, long illness duration, low socioeconomic status, and family history of mood disorders were associated with poorer outcomes.

CONCLUSIONS

Bipolar spectrum disorders in youths are characterized by episodic illness with subsyndromal and, less frequently, syndromal episodes with mainly depressive and mixed symptoms and rapid mood changes.

Earliest symptoms discriminating juvenile-onset bipolar illness from ADHD

OBJECTIVES

Controversy surrounds the diagnosis and earliest symptoms of childhood-onset bipolar illness, emphasizing the importance of prospective longitudinal studies. To acquire a preliminary, more immediate view of symptom evolution, we examined the course of individual symptoms over the first 10 years of life in juvenile-onset bipolar illness (JO-BP) compared with attention-deficit hyperactivity disorder (ADHD).

METHODS

Parents of formally diagnosed children retrospectively rated 37 symptoms in each year of the child's life based on the degree of dysfunction in their child's usual family, social, or educational roles. A subset of children with onset of bipolar disorder prior to age 9 (JO-BP) compared with those with ADHD was the focus of this analysis.

RESULTS

Brief and extended periods of mood elevation and decreased sleep were strong early differentiators of JO-BP and ADHD children. Depressive and somatic symptoms were later differentiators. Irritability and poor frustration tolerance differentiated the two groups only in their greater incidence and severity in JO-BP compared with a moderate occurrence in ADHD. In contrast, hyperactivity, impulsivity, and decreased attention showed highly similar trajectories in the two groups.

CONCLUSIONS

Elevated mood and decreased sleep discriminated JO-BP and ADHD as early as age 3, while classic ADHD symptoms were parallel in the groups. These retrospective results provide preliminary insights into symptom differences and their temporal evolution between bipolar disorder and ADHD in the first 10 years of life.

Magnetic resonance imaging studies in early onset bipolar disorder: an updated review

Over the past 5-10 years, advances in neuroimaging methods and study designs have begun to appear in the literature of early-onset bipolar disorder (onset before 18 years of age). This article contains an updated review of the literature regarding neuroimaging in youths with bipolar disorder (BPD), highlighting important new study designs and techniques. Overall, structural, functional (fMRI) and magnetic resonance spectroscopy (MRS) report consistent abnormalities in regions of the frontal lobe and limbic structures. Functional MRI and MRS studies also frequently report striatal and thalamic abnormalities in early-onset BPD. Future neuroimaging studies in youths with BPD should include longitudinal studies incorporating multimodal neuroimaging techniques.

Pharmacologic treatment of pediatric bipolar disorder

Bipolar disorder (BPD) is being diagnosed with increasing frequency in the pediatric population as the phenomenology of this disorder is becoming more clearly delineated. Early diagnosis and treatment of pediatric BPD is important to minimize psychosocial disability and improve prognosis. Traditional mood stabilizers and atypical antipsychotic agents are frequently used to treat BPD in youth, and there are emerging data to support their use in this population. This article provides a review of the literature on appropriate pharmacologic treatment strategies for BPD in children and adolescents. The complex treatment issues of comorbid BPD and attention deficit/hyperactivity disorder also are addressed.

Family and genetic association studies of bipolar disorder in children

The risk of bipolar disorder (BPD) (15-42%) in first-degree relatives of children with BPD are consistently larger than the 8.7% estimate of recurrence risk of BPD in first-degree relatives of adult BPD cases. There have been no family linkage studies of pediatric BPD, but secondary analyses of adult linkage samples suggest that early-onset BPD both increases the strength of associations in linkage studies. Positive associations with pediatric BPD and the BDNF gene (Vall66), the GAD1 gene (4s2241165), and the dopamine transporter gene (rs41084) have been reported but none of these associations have been replicated in independent samples. The number of informative families examined so far is quite small and studies were vastly underpowered to detect small effects. An adequately powered sample will likely require collaborative ascertainment of cases and families from multiple sites using valid and accepted measures of pediatric BPD.

Lifetime psychiatric disorders in school-aged offspring of parents with bipolar disorder: the Pittsburgh Bipolar Offspring study

CONTEXT

Whether offspring of parents with bipolar disorder (BP) are at specifically high risk to develop BP and other psychiatric disorders has not been adequately studied.

OBJECTIVE

To evaluate lifetime prevalence and specificity of psychiatric disorders in offspring of parents with BP-I and BP-II.

DESIGN

Offspring aged 6 to 18 years who have parents with BP and community control subjects were interviewed with standardized instruments. All research staff except the statistician were blind to parental diagnoses.

SETTING

Parents with BP were recruited primarily through advertisement and outpatient clinics. Control parents were ascertained by random-digit dialing and were group matched for age, sex, and neighborhood to parents with BP.

PARTICIPANTS

Three hundred eighty-eight offspring of 233 parents with BP and 251 offspring of 143 demographically matched control parents.

MAIN OUTCOME MEASURES

Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) Axis I disorders.

RESULTS

Adjusting for demographic factors, living with 1 vs both biological parents, both biological parents' non-BP psychopathology, and within-family correlations, offspring of parents with BP showed high risk for BP spectrum disorders (odds ratio [OR] = 13.4; 95% confidence interval [CI], 2.9-61.6) and any mood (OR = 5.2; 95% CI, 2.3-11.4), anxiety (OR = 2.3; 95% CI, 1.3-4.0), and Axis I (OR = 2.2; 95% CI, 1.5-3.3) disorders. Offspring of parents with BP with high socioeconomic status showed more disruptive behavior disorders and any Axis I disorders than offspring of control parents with high socioeconomic status. Families in which both parents had BP had more offspring with BP than families with only 1 parent with BP (OR = 3.6; 95% CI, 1.1-12.2). More than 75.0% of offspring who developed BP had their first mood episode before age 12 years, with most of these episodes meeting criteria for BP not otherwise specified and, to a lesser degree, major depression.

CONCLUSIONS

Offspring of parents with BP are at high risk for psychiatric disorders and specifically for early-onset BP spectrum disorders. These findings further support the familiality and validity of BP in youth and indicate a need for early identification and treatment.

The genetic etiology of childhood depressive symptoms: A developmental perspective

Although there is some evidence to suggest that depressive symptoms show age-related changes, it remains uncertain as to whether there are also developmental variations in the etiology of depression. In this article, we present findings from a population-based study of twins aged 8 to 16 years with the aim of examining the genetic etiology of depressive symptoms and the effects of age. The results suggest that environmental factors influence the transmission of depressive symptoms in childhood. However depressive symptoms in adolescence appear to be highly heritable. The etiology of depressive symptoms was further explored using factor-derived scores that again suggested the importance of genetic factors in adolescence. However there was some suggestion that genetic influences may contribute to certain types of symptoms (self-deprecation/self-esteem) even in childhood.

Family-based association study of the BDNF, COMT and serotonin transporter genes and DSM-IV bipolar-I disorder in children

BACKGROUND

Over the past decade pediatric bipolar disorder has gained recognition as a potentially more severe and heritable form of the disorder. In this report we test for association with genes coding brain-derived neurotrophic factor (BDNF), the serotonin transporter (SLC6A4), and catechol-O-methyltransferase (COMT).

METHODS

Bipolar-I affected offspring triads (N = 173) were drawn from 522 individuals with 2 parents in 332 nuclear families recruited for genetic studies of pediatric psychopathology at the Clinical and Research Program in Pediatric Psychopharmacology and Adult ADHD at Massachusetts General Hospital.

RESULTS

We failed to identify an association with the val66 allele in BDNF (OR = 1.23, p = 0.36), the COMT-l allele (OR = 1.27, p = 0.1), or the HTTLPR short allele (OR = 0.87, p = 0.38).

CONCLUSION

Our study suggests that the markers examined thus far in COMT and SLC6A4 are not associated with pediatric bipolar disorder and that if the val66met marker in BDNF is associated with pediatric bipolar disorder the magnitude of the association is much smaller than first reported.

[Pharmacotherapy in bipolar disorders during childhood and adolescence]

OBJECTIVE

Bipolar disorders during childhood and adolescence are rare, but serious and highly recurrent disorders, often associated with negative outcome. Pharmacotherapy, including Lithium, other mood stabilizers and typical antipsychotic agents, is the first-line treatment in bipolar disorders and often necessary for many months or years.

METHOD

A computerized medline-search (Pubmed) was made for prospective studies and reviews of bipolar disorder in this age-group published during the last 10 years, which were then reviewed for their relevance.

RESULTS

Despite the widespread use of substances whose efficacy for adults is well-established, there is a substantial lack of empirical data regarding the efficacy and safety in the treatment of bipolar disorder in children and adolescents. Placebo-controlled studies are very rare, and the interpretation of the existing data is complicated by the diagnostic controversy about bipolar disorder in children. Side-effects are more common in children and adolescents than in adults.

CONCLUSIONS

Combination therapy may be favoured in cases of severe and psychotic bipolar disorder. Needed are more placebo-controlled studies and long-term studies on the efficacy and safety of mood stabilizers and atypical antipsychotic agents in the treatment of children and adolescents with bipolar disorder.