Attention-deficit hyperactivity disorder with bipolar disorder: a familial subtype?

Working memory network alterations and associated symptoms in adults with ADHD and Bipolar Disorder

Attention-Deficit/Hyperactivity Disorder (ADHD) and Bipolar Disorder (BPD) co-occur frequently and represent a particularly morbid clinical form of both disorders, however underlying neural circuitry contributing to the comorbidity remain understudied. Our aim was to investigate functional brain circuitry during working memory in a group of participants who meet criteria for both disorders (ADHD + BPD), and to explore the relationship of symptoms of each disorder to brain function. We used fMRI to image brain activity in 18 male adults with both ADHD and BPD, and 18 healthy control participants matched one-to-one on age, sex, and handedness, while they performed a sequential letter N-back task. We investigated differences in activation between these groups, and also correlations of brain activity during the task to symptoms of ADHD and BPD independently. We found significant hypoactivity in the subjects with ADHD + BPD vs. controls across frontal and parietal regions, and further, found that BPD and ADHD symptoms related to activity in anatomically distinct regions that were respectively characterized by activation and suppression during task. We conclude that comorbid ADHD + BPD is associated with alterations across anterior and posterior nodes of the working memory network, and symptoms of each disorder are related to anatomically and functionally distinct brain regions.

Safety of stimulant treatment in attention deficit hyperactivity disorder: part II

IMPORTANCE OF THE FIELD

Attention deficit hyperactivity disorder (ADHD) is the most common childhood psychiatric disorder and in at least 50% of cases persists into adulthood. Treatment of ADHD with stimulants is one of the oldest and most effective pharmacological treatments in psychiatry. Yet, there continues to be controversy over the safety of stimulant medications in the treatment of ADHD.

AREAS COVERED IN THIS REVIEW

This paper is a continuation of an earlier paper that reviewed the safety profile of newer stimulant agents, especially in relation to special populations. This part II reviews, through essentially an organ-system approach, the various clinical concerns that have been raised over the safety of stimulant medications. This includes neuropsychiatric, cardiovascular effects on growth and development, and a number of other less common concerns.

WHAT THE READER WILL GAIN

A thorough review of safety concerns in stimulants that emphasizes clinical information, case reports, open series or controlled trials relating to stimulant use in the treatment of ADHD.

TAKE HOME MESSAGE

While many safety concerns have been raised in the use of stimulants, the vast majority of treatment complications are either quickly reversible or easily manageable with appropriate clinical care. The negative consequences of untreated ADHD clearly outweigh the risks of the stimulant medicines when used in an appropriate and careful manner.

Bipolar disorder risk alleles in adult ADHD patients

Attention-deficit/hyperactivity disorder (ADHD) has an estimated prevalence of 3-5% in adults. Genome-wide association (GWA) studies have not been performed in adults with ADHD and studies in children have so far been inconclusive, possibly because of the small sample sizes. Larger GWA studies have been performed on bipolar disorder (BD) and BD symptoms, and several potential risk genes have been reported. ADHD and BD share many clinical features and comorbidity between these two disorders is common. We therefore wanted to examine whether the reported BD genetic variants in CACNA1C, ANK3, MYO5B, TSPAN8 and ZNF804A loci are associated with ADHD or with scores on the Mood Disorder Questionnaire (MDQ), a commonly used screening instrument for bipolar spectrum disorders. We studied 561 adult Norwegian ADHD patients and 711 controls from the general population. No significant associations or trends were found between any of the single nucleotide polymorphisms (SNPs) studied and ADHD [odds ratios (ORs) ≤ 1.05]. However, a weak association was found between rs1344706 in ZNF804A (OR = 1.25; P = 0.05) and MDQ. In conclusion, it seems unlikely that these six SNPs with strong evidence of association in BD GWA studies are shared risk variants between ADHD and BD.

Lifetime psychopathology among the offspring of Bipolar I parents

BACKGROUND

Recent studies have demonstrated high rates of psychopathology in the offspring of parents with bipolar disorder. The aim of this study was to identify psychiatric diagnoses in a sample of children of bipolar parents.

METHOD

This case series comprised 35 children and adolescents aged 6 to 17 years, with a mean age of 12.5 ± 2.9 years (20 males and 15 females), who had at least one parent with bipolar disorder type I. The subjects were assessed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children - Present and Lifetime version (K-SADS-PL). Family psychiatric history and demographics were also evaluated.

RESULTS

Of the offspring studied, 71.4% had a lifetime diagnosis of at least one psychiatric disorder (28.6% with a mood disorder, 40% with a disruptive behavior disorder and 20% with an anxiety disorder). Pure mood disorders (11.4%) occurred less frequently than mood disorders comorbid with attention deficit hyperactivity disorder (17.1%). Psychopathology was commonly reported in second-degree relatives of the offspring of parents with bipolar disorder (71.4%).

CONCLUSIONS

Our results support previous findings of an increased risk for developing psychopathology, predominantly mood and disruptive disorders, in the offspring of bipolar individuals. Prospective studies with larger samples are needed to confirm and expand these results.

Bipolar and ADHD Comorbidity: Both Artifact and Outgrowth of Shared Mechanisms

Published rates of comorbidity between pediatric bipolar disorder (PBD) and attention-deficit/hyperactivity disorder (ADHD) have been higher than would be expected if they were independent conditions, but also dramatically different across different studies. This review examines processes that could artificially create the appearance of comorbidity or substantially bias estimates of the ADHD-BPD comorbidity rate, including: categorization of dimensional constructs, overlap among diagnostic criteria, over-splitting, developmental sequencing, and referral or surveillance biases. Evidence also suggests some mechanisms for "true" BPD-ADHD comorbidity, including shared risk factors, distinct subtypes, and weak causal relationships. Keys to differential diagnosis include focusing on episodic presentation and non-overlapping symptoms unique to mania.

Reasons for substance use among adolescents with bipolar disorder

We examined whether children and adolescents with bipolar disorder (BPD) "self-medicate" with cigarettes, alcohol, or other substances of abuse. One hundred and five adolescents with BPD and 98 controls were comprehensively assessed with a structured psychiatric diagnostic interview for psychopathology and the Drug Use Screening Inventory (DUSI) for self-medication. Thirteen control (mean ± standard deviation [SD]= 15.31 ± 1.18 years) and 27 BPD (15.30 ± 2.09 years) subjects endorsed use of one of the listed drugs in the DUSI Section A within the past year and were included in all analyses. BPD adolescents were more likely than nonmood disordered, substance-using controls to report starting to use their preferred drug for mood-altering effects. There were no differences between groups in motivation for use with respect to starting substances to sleep better or get high, or in continuing substances to change mood, sleep better, or get high. These data may contribute to increased prevention of substance use disorders and to the treatment of adolescent BPD. Further studies clarifying the characteristics of self-medication are necessary.

Risk factors predicting onset and persistence of subthreshold expression of bipolar psychopathology among youth from the community

OBJECTIVE

To examine factors increasing the risk for onset and persistence of subthreshold mania and depression.

METHOD

In a prospective cohort community study, the association between risk factors [a family history of mood disorders, trauma, substance use, attention-deficit/hyperactivity disorder (ADHD) and temperamental/personality traits] and onset of manic/depressive symptoms was determined in 705 adolescents. The interaction between baseline risk factors and baseline symptoms in predicting 8-year follow-up symptoms was used to model the impact of risk factors on persistence.

RESULTS

Onset of manic symptoms was associated with cannabis use and novelty seeking (NS), but NS predicted a transitory course. Onset of depressive symptoms was associated with a family history of depression. ADHD and harm avoidance (HA) were associated with persistence of depressive symptoms, while trauma and a family history of depression predicted a transitory course.

CONCLUSION

Different risk factors may operate during onset and persistence of subthreshold mania and depression. The differential associations found for mania and depression dimensions suggest partly different underlying mechanisms.

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.

Adult ADHD and its comorbidities, with a focus on bipolar disorder

Attention deficit hyperactivity disorder (ADHD) is a syndrome that most often presents in childhood. However, the condition is also relatively common in adults, with prevalence rates reaching 5% in the general population, with more than half the children affected by ADHD retaining the condition during their adult years. While the disorder in children is most often described as a disorder involving hyperactivity and impulsiveness, ADHD presents with very different characteristics in adulthood, notably with less externalizing symptoms and with a higher rate of psychiatric comorbidities, including major depressive disorder, bipolar disorder (BD), anxiety disorders and substance abuse. This review will focus on the evidence relating to bipolar disorder BD and its potential link with ADHD, looking at epidemiological, familial and neuroimaging studies. The comorbid presentation of people suffering with ADHD and BD (ADHD/BD) is associated with a more severe disease course, more severe mood disorder symptoms, and lower functional scores. Importantly, the co-segregation of these two conditions makes ADHD diagnosis challenging because its symptoms are often mistakenly assumed to be part of BD. As a result, patients with comorbid ADHD/BD are under-diagnosed and under-treated. Optimal diagnosis, understanding and treatment of the comorbid condition are important, as ADHD/BD has been associated with significant functional impairment and suboptimal treatment responses when compared to ADHD or BD populations alone.

A genome-wide association study of bipolar disorder and comorbid migraine

Both migraine and bipolar affective disorder (BPAD) are complex phenotypes with significant genetic and nongenetic components. Epidemiological and clinical studies have showed a high degree of comorbidity between migraine and BPAD, and overlapping regions of linkage have been shown in numerous genome-wide linkage studies. To identify susceptibility factors for the BPAD/migraine phenotype, we conducted a genome-wide association study (GWAS) in 1001 cases with bipolar disorder collected through the NIMH Genetics Initiative for Bipolar Disorder and genotyped at 1 m single-nucleotide polymorphisms (SNPs) as part of the Genetic Association Information Network (GAIN). We compared BPAD patients without any headache (n = 699) with BPAD patients with doctor diagnosed migraine (n = 56). The strongest evidence for association was found for several SNPs in a 317-kb region encompassing the uncharacterized geneKIAA0564 {e.g. rs9566845 [OR = 4.98 (95% CI: 2.6-9.48), P = 7.7 × 10(-8)] and rs9566867 (P = 8.2 × 10(-8))}. Although the level of significance was significantly reduced when using the Fisher's exact test (as a result of the low count of cases with migraine), rs9566845 P = 1.4 × 10(-5) and rs9566867 P = 1.5 × 10(-5), this region remained the most prominent finding. Furthermore, marker rs9566845 was genotyped and found associated with migraine in an independent Norwegian sample of adult attention deficit hyperactivity disorder (ADHD) patients with and without comorbid migraine (n = 131 and n = 324, respectively), OR = 2.42 (1.18-4.97), P = 0.013. This is the first GWAS examining patients with bipolar disorder and comorbid migraine. These data suggest that genetic variants in the KIAA0564 gene region may predispose to migraine headaches in subgroups of patients with both BPAD and ADHD.

[Bipolar disorders as co-morbidity in childhood and adolescence--underdiagnosed or overinterpreted? Therapy of a 14-year-old boy with hyperkinetic conduct disorder and hypomania]

OBJECTIVE

Considerable debate exists regarding differing prevalence rates of co-morbid bipolar disorder in children and adolescents with ADHD in Germany as compared to the US.

METHODS

Described in this case report are the assessment of and treatment procedure for a 14-year old boy with hyperkinetic conduct disorder and co-morbid hypomanic episode, as well as different possible interpretations of symptoms.

CONCLUSIONS

Further studies of children and adolescents with ADHD and coexisting impulsive-aggressive behaviour are needed. Important in practice is a precise differentiation of symptoms with regard to co-morbid bipolar disorder.

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.

Occupational outcome in adult ADHD: impact of symptom profile, comorbid psychiatric problems, and treatment: a cross-sectional study of 414 clinically diagnosed adult ADHD patients

OBJECTIVE

To determine the effects of symptom profile, comorbid psychiatric problems, and treatment on occupational outcome in adult ADHD patients.

METHOD

Adult ADHD patients (N = 414) responded to questionnaires rating past and present symptoms of ADHD, comorbid conditions, treatment history, and work status.

RESULTS

Of the patients, 24% reported being in work, compared to 79% in a population-based control group (N = 359). Combined subtype of ADHD, substance abuse, and a reported history of depression or anxiety were correlated with being out of work. Current and past medical treatment of ADHD was correlated with being in work. Logistic regression analyses showed that stimulant therapy during childhood was the strongest predictor for being in work as adults (odds ratio = 3.2, p = .014).

CONCLUSION

Early recognition and treatment of ADHD is a strong predictor of being in work as an adult, independently of comorbidity, substance abuse, and current treatment.

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.

The Child Behavior Checklist-Pediatric Bipolar Disorder profile predicts a subsequent diagnosis of bipolar disorder and associated impairments in ADHD youth growing up: a longitudinal analysis

OBJECTIVE

To examine the predictive utility of the Child Behavior Checklist-Pediatric Bipolar Disorder (CBCL-PBD) profile to help identify children at risk for bipolar disorder.

METHOD

Subjects were ascertained from 2 identically designed longitudinal case-control family studies of subjects (males and females aged 6-18 years) with DSM-III-R attention-deficit/hyperactivity disorder (ADHD). Based on data from the baseline assessment, ADHD subjects without a lifetime diagnosis of bipolar disorder were stratified by the presence (CBCL-PBD positive, N=28) or absence (CBCL-PBD negative, N=176) of a CBCL-PBD score > or = 210 (total of attention, aggression, and anxious/depressed subscales). Subjects were comprehensively assessed at follow-up with structured psychiatric interviews. Data were collected from April 1988 to February 2003.

RESULTS

Over a mean follow-up period of 7.4 years, a positive CBCL-PBD score predicted subsequent diagnoses of bipolar disorder, major depressive disorder, and conduct disorder, as well as impaired psychosocial functioning and higher risk for psychiatric hospitalization.

CONCLUSION

This work suggests that a positive CBCL-PBD score based on elevations on the attention problems, aggressive behavior, and anxious/depressed subscales predicts subsequent pediatric bipolar disorder and associated syndrome-congruent impairments. If confirmed in other studies, the CBCL-PBD score has the potential to help identify children at high risk to develop bipolar disorder.

Comorbidity in Pediatric Bipolar Disorder

The growing literature shows the pervasiveness and importance of comorbidity in youth with bipolar disorder (BPD). For instance, up to 90% of youth with BPD have been described to manifest comorbidity with attention-deficit hyperactivity disorder. Multiple anxiety, substance use, and disruptive behavior disorders are the other most commonly reported comorbidities with BPD. Moreover, important recent data highlight the importance of obsessive-compulsive and pervasive developmental illness in the context of BPD. Data suggest that not only special developmental relationships are operant in the context of comorbidity but also that the presence of comorbid disorders with BPD results in a more severe clinical condition. Moreover, the presence of comorbidity has therapeutic implications for the treatment response for both BPD and the associated comorbid disorder. Future longitudinal studies to address the relationship and the impact of comorbid disorders on course and therapeutic response over time are required in youth with BPD.

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.

Attention deficit-hyperactivity disorder and early-onset bipolar disorder: two facets of one entity?

Early-onset bipolar disorder (BD) and attention-deficithyperactivity disorder (ADHD) have recently been the subject of highly controversial debate, due to theories regarding underlying pathophysiological processes and a clinical overlap of symptoms. Epidemiological data, clinical aspect, neuroimaging, neurochemical, and genetic studies suggest that there may be a possible relationship between biological factors and clinical characteristic in the development of symptoms. However, longitudinal data supporting the hypothesis of a diagnostic shift from BD to ADHD symptoms and vice versa are currently not available. These would be essential to enable further investigations into whether these two disorders possibly represent two different aspects of an underlying common psychopathophysioiogical entity.

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.

Comparison of manic and depressive symptoms between children and adolescents with bipolar spectrum disorders

OBJECTIVE

To compare the most severe lifetime (current or past) mood symptoms, duration of illness, and rates of lifetime comorbid disorders among youth with bipolar spectrum disorders [BP (bipolar-I, bipolar-II and bipolar-not otherwise specified)].

METHODS

A total of 173 children (<12 years) with BP, 101 adolescents with childhood-onset BP, and 90 adolescents with adolescent-onset BP were evaluated with standardized instruments.

RESULTS

Depression was the most common initial and frequent episode for both adolescent groups, followed by mania/hypomania. Adolescents with childhood-onset BP had the longest illness, followed by children and then adolescents with adolescent-onset BP. Adjusting for sex, socioeconomic status, and duration of illness, while manic, both adolescent groups showed more 'typical' and severe manic symptoms. Mood lability was more frequent in childhood-onset and adolescents with early-onset BP. While depressed, both adolescent groups showed more severe depressive symptoms, higher rates of melancholic and atypical symptoms, and suicide attempts than children. Depressed children had more severe irritability than depressed adolescents. Early BP onset was associated with attention-deficit hyperactivity disorder, whereas later BP onset was associated with panic, conduct, and substance use disorders. Above-noted results were similar when each BP subtype was analyzed separately.

CONCLUSIONS

Older age was associated with more severe and typical mood symptomatology. However, there were differences and similarities in type, intensity, and frequency of BP symptoms and comorbid disorders related to age of onset and duration of BP and level of psychosocial development. These factors and the normal difficulties youth have expressing and modulating their emotions may explain existing complexities in diagnosing and treating BP in youth, particular in young children, and suggest the need for developmentally sensitive treatments.

Disruptive behavior disorders in offspring of parents with major depression: associations with parental behavior disorders

OBJECTIVE

Although the offspring of parents with major depressive disorder (MDD) are at increased risk to develop disruptive behavior disorders (DBD) in addition to MDD, it remains unclear whether this heightened risk is due to MDD or to comorbid DBD in the parents.

METHOD

In a secondary analysis of longitudinal data from offspring at risk for MDD and panic disorder and comparison children, we stratified 169 children of parents who had been treated for MDD based upon presence (n=50) or absence (n=119) of parental history of DBD (ADHD, oppositional disorder, and conduct disorder) and contrasted them with children of parents with DBD but without MDD (n=19) and children whose parents had neither MDD nor DBD (n=106). The children had been assessed in middle childhood using structured diagnostic interviews.

RESULTS

Offspring of parents with MDD + DBD had significantly higher rates of MDD, DBD in general, and ADHD in particular, compared with offspring of parents with MDD alone. Offspring of parents with MDD + DBD also had higher rates of mania than controls. Both parental MDD and DBD conferred independent risk for MDD and DBD in the offspring. However, only parental DBD conferred independent risk for conduct disorder and ADHD and only parental MDD conferred independent risk for oppositional defiant disorder.

CONCLUSION

Elevated rates of DBD in the offspring of parents with MDD appear to be due in part to the presence of DBD in the parents. Further studies of samples not selected on the basis of parental panic disorder are needed to confirm these results.

Bipolar disorder--methodological problems and future perspectives

Since its “rebirth” in 1966, bipolar disorder (BPD) has rapidly come to occupy a central position in the research and treatment of mood disorders. Compared with major depressive disorder (MDD), BPD is a more serious condition, characterized by much more frequent recurrence, more complex comorbidity, and higher mortality. One major problem is the lack of valid definitions in adult and in child psychiatry; the current definitions are unsatisfactory, and heavily favor an overdiagnosis of MDD. Biological research is partially based on those definitions, which have a short half-life. An additional, dimensional, approach, quantifying hypomania, depression, and anxiety by self-assessment and symptom checklists is recommended, A further, related problem is the early recognition of the onset of BPD, especially in adolescence, and the identification of correlates in childhood. Early and timely diagnosis of BPD is necessary to enable prompt intervention and secondary prevention of the disorder. The paper describes the current status and future directions of developing clinical concepts of bipolarity

Family based association study of pediatric bipolar disorder and the dopamine transporter gene (SLC6A3)

The dopamine transporter gene (SLC6A3) is a compelling candidate for pediatric bipolar disorder because (a) it has been associated with ADHD, (b) bipolar comorbidity with ADHD has been hypothesized to be an etiologically distinct familial subtype (c) blockade of the dopamine transporter with psychostimulants can induce mania in susceptible individuals and (d) previous studies have implicated the gene in bipolar disorder in adults. We conducted a family-based association study of SLC6A3 in 170 affected offspring trios defined by a child (12.9 +/- 5.3 years of age)with DSM-IV Bipolar-I disorder. Twenty-eight tag SNPs were chosen from the CEU (European) population of the International HapMap project (www.hapmap.org). Results indicated nominally positive association for 4 SNPs (rs40184, rs11133767, rs3776512, and rs464049), but only rs40184 survived correction for multiple statistical comparisons (P = 0.038). This is the first examination of the association with SLC6A3 and bipolar disorder in children and, like previous findings in adults with bipolar disorder, we found evidence of association with SNPs in the 3' region of the gene. These data provide suggestive evidence supporting a role for SLC6A3 in the etiology of pediatric bipolar disorder.

Towards further understanding of the co-morbidity between attention deficit hyperactivity disorder and bipolar disorder: a MRI study of brain volumes

BACKGROUND

Although attention deficit hyperactivity disorder (ADHD) and bipolar disorder (BPD) co-occur frequently and represent a particularly morbid clinical form of both disorders, neuroimaging research addressing this co-morbidity is scarce. Our aim was to evaluate the morphometric magnetic resonance imaging (MRI) underpinnings of the co-morbidity of ADHD with BPD, testing the hypothesis that subjects with this co-morbidity would have neuroanatomical correlates of both disorders.

METHOD

Morphometric MRI findings were compared between 31 adults with ADHD and BPD and with those of 18 with BPD, 26 with ADHD, and 23 healthy controls. The volumes (cm(3)) of our regions of interest (ROIs) were estimated as a function of ADHD status, BPD status, age, sex, and omnibus brain volume using linear regression models.

RESULTS

When BPD was associated with a significantly smaller orbital prefrontal cortex and larger right thalamus, this pattern was found in co-morbid subjects with ADHD plus BPD. Likewise, when ADHD was associated with significantly less neocortical gray matter, less overall frontal lobe and superior prefrontal cortex volumes, a smaller right anterior cingulate cortex and less cerebellar gray matter, so did co-morbid ADHD plus BPD subjects.

CONCLUSIONS

Our results support the hypothesis that ADHD and BPD independently contribute to volumetric alterations of selective and distinct brain structures. In the co-morbid state of ADHD plus BPD, the profile of brain volumetric abnormalities consists of structures that are altered in both disorders individually. Attention to co-morbidity is necessary to help clarify the heterogeneous neuroanatomy of both BPD and ADHD.

Mood and disruptive behavior disorders and symptoms in the offspring of patients with bipolar I disorder

The study aimed to ascertain the prevalence of mood and disruptive behavior disorders and symptoms in 35 children of 29 adult outpatients with a DSM-IV diagnosis of bipolar I disorder, compared with 33 children of 29 healthy adults, matched with patients on age, socioeconomic status and education. The offspring of bipolar patients had a 9.48 fold higher risk of receiving a psychiatric diagnosis. While only two children of patients with bipolar disorder were diagnosed with a mood disorder, 30.9% displayed mild depressed mood, compared with 8.8% of the controls, a statistically significant difference. The bipolar offspring also scored significantly higher on the hyperactivity and conduct problems subscales as well as the ADHD index of the Conners' Teacher Rating Scale. The disruptive behavior and mood symptoms observed in early life in the offspring of bipolar patients may indicate the need for early psychosocial intervention.

Mood lability and bipolar disorder in children and adolescents

Pediatric bipolar disorder, once considered rare, has reportedly increased in incidence over the past 10 years. There is significant debate about the phenomenology, diagnosis and treatment of this illness. The diagnostic assessment of children with severe mood and behavioural disturbance is of considerable public health importance as the ultimate diagnosis can have significant treatment implications and can impact the level of stigma experienced by children and their families. The purposes of this paper are to: 1) review current issues in the phenomenology and diagnostic assessment of bipolar disorder in children and adolescents; 2) review recent research suggesting that youths with a chronic course of illness should be considered a separate group from those with an episodic course; and 3) offer suggestions for future studies to address the various phenomenological controversies.

Frontiers between attention deficit hyperactivity disorder and bipolar disorder

The co-occurrence of attention deficit hyperactivity disorder (ADHD) and bipolar disorder has received much recent attention in the literature. The authors review the literature examining associations between ADHD and bipolar disorder in children, and data concerning severe irritability in youth with ADHD. This article focuses on (1) population-based studies examining ADHD and bipolar disorder or ADHD and co-occurring irritability, (2) the co-occurrence and prospective relationships of ADHD and bipolar disorder in clinical samples, (3) phenomenology and assessment of bipolar disorder and ADHD, (4) treatment of comorbid ADHD and bipolar disorder, (5) family and genetic studies of ADHD and bipolar disorder, and (6) pathophysiologic comparisons between children with ADHD and irritability and bipolar disorder. We draw on the research to make clinical recommendations and highlight important directions for future research.

Pediatric bipolar disorder: validity, phenomenology, and recommendations for diagnosis

OBJECTIVE

To find, review, and critically evaluate evidence pertaining to the phenomenology of pediatric bipolar disorder and its validity as a diagnosis.

METHODS

The present qualitative review summarizes and synthesizes available evidence about the phenomenology of bipolar disorder (BD) in youths, including description of the diagnostic sensitivity and specificity of symptoms, clarification about rates of cycling and mixed states, and discussion about chronic versus episodic presentations of mood dysregulation. The validity of the diagnosis of BD in youths is also evaluated based on traditional criteria including associated demographic characteristics, family environmental features, genetic bases, longitudinal studies of youths at risk of developing BD as well as youths already manifesting symptoms on the bipolar spectrum, treatment studies and pharmacologic dissection, neurobiological findings (including morphological and functional data), and other related laboratory findings. Additional sections review impairment and quality of life, personality and temperamental correlates, the clinical utility of a bipolar diagnosis in youths, and the dimensional versus categorical distinction as it applies to mood disorder in youths.

RESULTS

A schema for diagnosis of BD in youths is developed, including a review of different operational definitions of 'bipolar not otherwise specified.' Principal areas of disagreement appear to include the relative role of elated versus irritable mood in assessment, and also the limits of the extent of the bipolar spectrum--when do definitions become so broad that they are no longer describing 'bipolar' cases?

CONCLUSIONS

In spite of these areas of disagreement, considerable evidence has amassed supporting the validity of the bipolar diagnosis in children and adolescents.

Prevention of bipolar disorder in at-risk children: theoretical assumptions and empirical foundations

This article examines how bipolar symptoms emerge during development, and the potential role of psychosocial and pharmacological interventions in the prevention of the onset of the disorder. Early signs of bipolarity can be observed among children of bipolar parents and often take the form of subsyndromal presentations (e.g., mood lability, episodic elation or irritability, depression, inattention, and psychosocial impairment). However, many of these early presentations are diagnostically nonspecific. The few studies that have followed at-risk youth into adulthood find developmental discontinuities from childhood to adulthood. Biological markers (e.g., amygdalar volume) may ultimately increase our accuracy in identifying children who later develop bipolar I disorder, but few such markers have been identified. Stress, in the form of childhood adversity or highly conflictual families, is not a diagnostically specific causal agent but does place genetically and biologically vulnerable individuals at risk for a more pernicious course of illness. A preventative family-focused treatment for children with (a) at least one first-degree relative with bipolar disorder and (b) subsyndromal signs of bipolar disorder is described. This model attempts to address the multiple interactions of psychosocial and biological risk factors in the onset and course of bipolar disorder.

Genomic imprinting and human psychology: cognition, behavior and pathology

Imprinted genes expressed in the brain are numerous and it has become clear that they play an important role in nervous system development and function. The significant influence of genomic imprinting during development sets the stage for structural and physiological variations affecting psychological function and behaviour, as well as other physiological systems mediating health and well-being. However, our understanding of the role of imprinted genes in behaviour lags far behind our understanding of their roles in perinatal growth and development. Knowledge of genomic imprinting remains limited among behavioral scientists and clinicians and research regarding the influence of imprinted genes on normal cognitive processes and the most common forms of neuropathology has been limited to date. In this chapter, we will explore how knowledge of genomic imprinting can be used to inform our study of normal human cognitive and behavioral processes as well as their disruption. Behavioural analyses of rare imprinted disorders, such as Prader-Willi and Angelman syndromes, provide insight regarding the phenotypic impact of imprinted genes in the brain, and can be used to guide the study of normal behaviour as well as more common but etiologically complex disorders such as ADHD and autism. Furthermore, hypotheses regarding the evolutionary development of imprinted genes can be used to derive predictions about their role in normal behavioural variation, such as that observed in food-related and social interactions.

The early manifestations of bipolar disorder: a longitudinal prospective study of the offspring of bipolar parents

OBJECTIVE

A major aim of this longitudinal high-risk study is to identify reliable early indicators of emerging bipolar disorder (BD) among offspring from well-characterized parents.

METHODS

High-risk offspring were recruited from families in which one parent had BD diagnosed on the basis of the Schedule for Affective Disorders and Schizophrenia - Lifetime version (SADS-L) interviews and DSM-IV diagnostic criteria and the other parent was well. Bipolar parents were further subdivided on the basis of response or non-response to long-term lithium. A comparison group of offspring was recruited from well parents diagnosed on the basis of either SADS-L interviews or the family history method. All consenting offspring from high-risk and control families were assessed longitudinally with the Schedule for Affective Disorders and Schizophrenia for School-aged Children - Present and Lifetime version (KSADS-PL) interviews and DSM-IV diagnoses were made on a blind consensus review. The offspring were reassessed on average annually, as well as at any time symptoms developed.

RESULTS

Antecedent conditions to BD in both high-risk groups included sleep and anxiety disorders, while attention-deficit hyperactivity disorder and pre-psychotic conditions were antecedents among the offspring of lithium non-responders only. Among those offspring developing BD, the index mood episode was almost always depressive.

CONCLUSIONS

Despite a specific genetic risk, BD began with non-specific psychopathology and/or depressive disorders in a majority of offspring. Therefore, diagnosis based only on cross-sectional assessment of symptoms appears to be insufficient for the accurate early detection of emerging BD. Other parameters such as family history and associated antecedents should be taken into account.

Current issues in bipolar disorder: a critical review

Although awareness on bipolar disorder has increased during the last decade, this condition remains characterized by a disabling burden, in terms of morbidity and functional impairment. This paper aims to review some critical issues in the current knowledge on Bipolar disorder. Although large European epidemiological studies are lacking, Bipolar disorder is characterized by a set of severe features, including an early age of onset, a chronic outcome and an important suicidal risk. A majority of bipolar patients also experience a comorbid Axis I condition, including substance abuse, anxiety disorder and attention-deficit hyperactivity disorder. This situation presents a therapeutic challenge, since antidepressants or methylphenidate may be associated with the risk of inducing mania. Recently, a large number of studies have provided evidence for the efficacy of new compounds in the treatment of both mania and bipolar depression, but also in long-term relapse prevention. Recent research has also allowed for the redefinition of the concept of mood stabilizer and for improving existing guidelines on the clinical management of Bipolar disorder.

Investigation of variation in SNAP-25 and ADHD and relationship to co-morbid major depressive disorder

Synaptosomal-associated protein of 25 kDa (SNAP-25), a protein involved in presynaptic neurotransmitter release, is a candidate gene for attention deficit/hyperactivity disorder (ADHD). Previous investigators have reported association initially with two single nucleotide polymorphisms (SNPs) (rs3746544, rs1051312) and their associated haplotypes. Subsequently, additional SNPs across the region were also reported to be associated with ADHD. We attempted to replicate these observations in a sample of 229 families with ADHD offspring by genotyping 61 SNPs spanning the region containing SNAP-25. A single SNP (rs3787283) which is in strong linkage disequilibrium (LD) with rs3746544 and rs1051312 (D' = 0.89-0.94) resulted in a nominally significant association (P = 0.002). When we pooled our data with those from prior studies, results were modestly significant for rs3746544 (P = 0.048) and rs6077690 (P = 0.031). As an attempt to determine if specific ADHD-related phenotypes may be more relevant to SNAP-25 than the categorical diagnosis, we carried out exploratory subgroup analysis in our ADHD sample according to co-morbid status. We found the strongest association result in the ADHD patients with co-morbid major depressive disorder (MDD). Six SNPs were nominally associated with the ADHD and co-morbid MDD cases (P = 0.012-0.045). Furthermore, a haplotype block located 11 kb 3' of the gene showed positive evidence for association with this phenotype (global P = 0.013). In conclusion, we report some evidence supporting the association of previously implicated SNPs (rs3746544, rs1051312) of SNAP-25 to ADHD. We further suggest that co-morbidity with MDD may enhance detection of the association between SNAP-25 and ADHD.

Attention-deficit/hyperactivity disorder: a neuropsychological perspective towards DSM-V

Neuropsychological methods and techniques have much to offer in the evaluation of the individual suspected as having Attention-Deficit/Hyperactivity Disorder (ADHD). After a review of the historical evolution of the ADHD concept, incidence and prevalence, and DSM-IV criteria for diagnosis, especially as regards omission related to gender differences, and other associated cultural, familial, socioenvironmental, and subject influences, this paper describes a number of dilemmas and obstacles encountered in clinical practice. Included are the confounds associated with the wide range of possible comorbidities, the insufficiency of current DSM-IV criteria, the emergence of subtype differentiation and its impact on diagnosis and treatment. The complex relationship between neuropsychological constructs and ADHD, and obstacles to valid assessment are also addressed. The complexities associated with a thorough ADHD evaluation are viewed within an impressive and expansive existing scientific framework and recommendations are made for future directions.

Test of Alternative Hypotheses Explaining the Comorbidity Between Attention-Deficit/Hyperactivity Disorder and Conduct Disorder

There is significant comorbidity between attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD). The conclusions of studies that examined the causes of comorbidity between ADHD and CD conflict, with some researchers finding support for the three independent disorders model and others finding support for the correlated risk factors model. We tested these models and eleven alternative hypotheses using the same analytical approach. The participants were 110 monozygotic twin pairs and 181 dizygotic twin pairs recruited from the Colorado Learning Disabilities Research Center Twin Study. The three independent disorders model did not fit the data, whereas the correlated risk factors model fit the data well. Several other comorbidity models fit the data as well as or better than the correlated risk factors model. The results suggest that correlated risk factors are a better explanation for the comorbidity between ADHD and CD than a third, independent ADHD+CD subtype.

Association of bipolar and substance use disorders in parents of adolescents with bipolar disorder

BACKGROUND

We have previously shown that juvenile bipolar disorder (BPD) is a risk for substance use disorders (SUD). Here we examine the expression of both disorders in families of youth with BPD to evaluate the familial risk mechanism.

METHODS

We studied 108 adolescent BPD probands with 187 parents (34 with SUD and 58 parents) and 96 control probands with 177 parents with structured interviews. We compared the prevalence of BPD and SUD with Cox proportional hazards models with time to onset of BPD or SUD as the dependent variable and proband diagnosis (Control, BPD, or BPD+SUD) as the independent variable.

RESULTS

The parents of the proband youth with BPD (without SUD) and BPD+SUD were more likely to develop BPD than the parents of control subjects [omnibus test chi2=10.18, p=.006]; we found no differences between the two bipolar groups. Parents of proband youth with BPD and with BPD+SUD were more likely than relatives of control subjects to develop SUD [omnibus test chi2=14.69, p<.001]; however, we found no differences between the parents of the two proband bipolar groups. Within the parents of proband youth with BPD+SUD, we found higher risk of SUD in parents with BPD than in those without BPD [chi2=8.39, p=.004], although the frequency of BPD was low in this group of parents.

CONCLUSIONS

Bipolar disorder and SUD are prevalent in the first-degree relatives of adolescents with BPD. Adults with BPD were more likely to manifest SUD with preliminary evidence of BPD and SUD cosegregation.

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.

Does bipolar disorder exist in children? A selected review

Although there is increasing recognition that a substantial proportion of patients with bipolar disorder (BD) experience an onset of illness in adolescence, significant controversy remains over the validity of the diagnosis in very young children. In careful studies of adult patients dating from Kraepelin, first mood episodes not uncommonly occurred during adolescence. Some of these early-onset patients experienced subthreshold mood disturbances or predisposing temperaments earlier in childhood. Earlier onsets of BD have been reported in more recent clinical and community samples of children. Several factors possibly contributed to these earlier onsets, including exposure to psychotropics, bias in favour of a mood rather than a psychotic diagnosis, and recognition of softer-spectrum BDs. However, the validity of the diagnosis of BD in impulsive, irritable, labile, or behaviourally dysregulated children remains to be proven. Studies of high-risk children of well-characterized parents with BD have demonstrated that BD most often debuts as a depressive episode in mid to late adolescence and that activated episodes are rare prior to age 12 years. Some children manifest antecedent nonspecific psychopathology in early childhood. Therefore, as currently diagnosed, BD does not manifest as such typically until at least adolescence.

Childhood antecedent disorders to bipolar disorder in adults: a controlled study

OBJECTIVE

The aim of the study was to examine antecedent childhood psychiatric disorders in adult patients with bipolar disorder.

METHOD

Using structured diagnostic interviews, childhood psychiatric diagnoses of 83 referred patients with diagnosed DSM-IV bipolar disorder were compared to those of 308 adults without mood disorders.

RESULTS

Patients with bipolar disorder had significantly higher rates of childhood disruptive behavior disorders (ADHD, oppositional-defiant disorder, and conduct disorder), childhood anxiety disorders (separation anxiety and overanxious disorder), and enuresis, compared to patients without mood disorders. The presence of these childhood disorders was associated with an earlier age of onset of bipolar illness.

LIMITATIONS

The retrospective nature of the study may have affected both the rates of disorders recalled, as well as the ages of onset of disorders. Different referral sources for bipolar and comparison participants may have also impacted findings.

CONCLUSIONS

Bipolar disorder in adults is frequently preceded by childhood disruptive behavior and anxiety disorders. These childhood disorders may be important markers of risk for adult bipolar disorder.

Practice parameter for the assessment and treatment of children and adolescents with bipolar disorder

This practice parameter reviews the literature on the assessment and treatment of children and adolescents with bipolar disorder. The parameter focuses primarily on bipolar 1 disorder because that is the type most often studied in juveniles. The presentation of bipolar disorder in youth, especially children, is often considered atypical compared with that of the classic adult disorder, which is characterized by distinct phases of mania and depression. Children who receive a diagnosis of bipolar disorder in community settings typically present with rapid fluctuations in mood and behavior, often associated with comorbid attention-deficit/hyperactivity disorder and disruptive behavior disorders. Thus, at this time it is not clear whether the atypical forms of juvenile mania and the classic adult form of the disorder represent the same illness. The question of diagnostic continuity has important treatment and prognostic implications. Although more controlled trials are needed, mood stabilizers and atypical antipsychotic agents are generally considered the first line of treatment. Although patients may respond to monotherapy, combination pharmacotherapy is necessary for some youth. Behavioral and psychosocial therapies are also generally indicated for juvenile mania to address disruptive behavior problems and the impact of the illness on family and community functioning.

Psychopathology in the young offspring of parents with bipolar disorder: a controlled pilot study

Studies have suggested that the offspring of parents with bipolar disorder are at risk for a spectrum of psychopathology, but few have focused on children in the youngest age ranges or examined the impact of comorbid parental disorders. We utilized a pre-existing sample of young (mean age: 6.8 years) offspring of parents with bipolar disorder (n=34), of parents with panic or major depression (n=179), and of parents with neither mood or anxiety disorder (n=95). Children were assessed blindly to parental diagnoses using the Schedule for Affective Disorders and Schizophrenia-Epidemiologic version (K-SADS-E). Offspring of bipolar parents had significantly higher rates of disruptive behavior and anxiety disorders than offspring from both of the comparison groups, accounted for by elevated rates of ADHD and overanxious disorder. These comparisons were significant even when lifetime histories of the corresponding categories of comorbid disorders in the parents (disruptive behavior disorders and anxiety disorders) were covaried. In addition, offspring of bipolar parents had increased rates of bipolar I disorder, compared with psychiatric controls. Results support the hypotheses of elevated behavior, anxiety, and mood disorders among offspring at risk for bipolar disorder, and suggest that this psychopathology is already evident in early childhood.

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.

Co-occurrence of bipolar and attention-deficit hyperactivity disorders in children

OBJECTIVES

Pediatric bipolar disorder (BPD) and attention-deficit hyperactivity disorder (ADHD) co-occur more frequently than expected by chance. In this review, we examine 4 potential explanations for the high rate of this common co-occurrence: (i) BPD symptom expression leads to overdiagnosis of ADHD in BPD youth; (ii) ADHD is a prodromal or early manifestation of pediatric-onset BPD; (iii) ADHD and associated factors (e.g., psychostimulants) lead to the onset of pediatric BPD; and (iv) ADHD and BPD share an underlying biological etiology (i.e., a common familial or genetic risk or underlying neurophysiology).

METHODS

Peer-reviewed publications of studies of children and adolescents with comorbid BPD and ADHD were reviewed.

RESULTS

There is a bidirectional overlap between BPD and ADHD in youth, with high rates of ADHD present in children with BPD (up to 85%), and elevated rates of BPD in children with ADHD (up to 22%). Phenomenologic, genetic, family, neuroimaging, and treatment studies revealed that BPD and ADHD have both common and distinct characteristics. While there are data to support all 4 explanations postulated in this paper, the literature most strongly suggests that ADHD symptoms represent a prodromal or early manifestation of pediatric-onset BPD in certain at-risk individuals. Bipolar disorder with comorbid ADHD may thus represent a developmentally specific phenotype of early-onset BPD.

CONCLUSIONS

The etiology of comorbid BPD and ADHD is likely multifactorial. Additional longitudinal and biological studies are warranted to clarify the relationships between BPD and ADHD since they may have important diagnostic and treatment implications.

Biological risk factors in pediatric bipolar disorder

BACKGROUND

The current study attempted to determine whether neurodevelopmental and acquired brain abnormalities are more common in pediatric bipolar disorder (PBD).

METHODS

The study sample consisted of 98 subjects with a mean age of 11.5 +/- 3.3 years comprising three demographically matched groups: healthy controls (HC, n = 28), subjects with bipolar disorder - Type I (PBD, n = 37), and bipolar disorder - Type I combined with attention deficit hyperactivity disorder (PBD+ADHD, n = 33). Family history of PBD was determined using the Family History Screen. Additional measures were administered to assess the history on perinatal risk, development milestones, serious physical illnesses, and head injury.

RESULTS

Logistic regression showed that that family history and perinatal risk factors predicted the diagnosis of PBD. PBD diagnosis was 15 times higher among those with a family history of BD. Second, for every additional perinatal risk factor such as prenatal exposure to drugs or birth complications, the risk of having a PBD diagnosis increased more than six-fold.

CONCLUSIONS

Having a positive familial history of BD in a first degree relative and perinatal insults may elevate the risk for developing PBD. Presence of these risk factors, especially in the context of clinical signs of affect dysregulation, should alert clinicians to screen for PBD.