What do childhood attention deficit/hyperactivity symptoms in depressed adults tell us about the bipolar spectrum?

Attention-Deficit/Hyperactivity Disorder and Major Depressive Disorder: Evidence From Multiple Genetically Informed Designs

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) and major depressive disorder (MDD) are two highly prevalent disorders that frequently co-occur. Prior evidence from genetic and cohort studies supports an association between ADHD and MDD. However, the direction and mechanisms underlying their association remain unclear. As onset of ADHD occurs in early life, it has been hypothesized that ADHD may cause MDD.

METHODS

We examined the association of ADHD with MDD using 3 different genetically informed methods to disentangle causality from confounding: 1) a nationwide longitudinal register-based full sibling comparison (N = 1,018,489) adjusting for shared familial confounding; 2) a prospective co-twin control study comprising 16,477 twins (5084 monozygotic and 11,393 dizygotic); and 3) a two-sample Mendelian randomization analysis using the largest available ADHD (N = 225,534) and MDD (N = 500,199) genome-wide association study summary statistics, adjusting for correlated and uncorrelated horizontal pleiotropy.

RESULTS

Sibling and twin comparisons indicated that individuals with ADHD have an increased risk for subsequent development of MDD (hazard ratio = 4.12 [95% CI 3.62-4.69]) after adjusting for shared genetic and familial factors and that ADHD scores endorsed by parents are positively associated with subsequent MDD scores at ages 15 and 18 years (b = 0.07 [95% CI 0.05-0.08] and b = 0.09 [95% CI 0.08-0.11], respectively). Mendelian randomization analyses showed that genetic liability for ADHD is causally related to MDD (odds ratio = 1.15 [95% CI 1.08-1.23]).

CONCLUSIONS

Our study provides consistent results across 3 different genetically informative approaches, strengthening the hypothesis that ADHD is causally related to MDD.

Networks of Neurodevelopmental Traits, Socioenvironmental Factors, Emotional Dysregulation in Childhood, and Depressive Symptoms Across Development in Two U.K. Cohorts

OBJECTIVE

Previous population-based studies have identified associations between childhood neurodevelopmental traits and depression in childhood, adolescence, and young adulthood. However, neurodevelopmental traits are highly correlated with each other, which could confound associations when traits are examined in isolation. The authors sought to identify unique associations between multiple neurodevelopmental traits in childhood and depressive symptoms across development, while taking into account co-occurring difficulties, in multivariate analyses.

METHODS

Data from two U.K. population-based cohorts, the Twins Early Development Study (TEDS) (N=4,407 independent twins) and the Avon Longitudinal Study of Parents and Children (ALSPAC) (N=10,351), were independently analyzed. Bayesian Gaussian graphical models were estimated to investigate pairwise conditional associations between neurodevelopmental traits (autism and ADHD symptoms and general cognitive, learning, and communication abilities), socioenvironmental stressors (academic performance and peer relations), and emotional dysregulation in childhood (ages 7-11) and depressive symptoms across development (ages 12, 16, and 21).

RESULTS

In both cohorts, bivariate correlations indicated several associations between neurodevelopmental traits and depressive symptoms across development. However, based on replicated findings across cohorts, these pairs of variables were mostly conditionally independent, and none were conditionally associated, after accounting for socioenvironmental stressors and emotional dysregulation. In turn, socioenvironmental stressors and emotional dysregulation were conditionally associated with both neurodevelopmental traits and depressive symptoms. Based on replicated findings across cohorts, neurodevelopmental traits in childhood could be associated only indirectly with depressive symptoms across development.

CONCLUSIONS

This study indicates that associations between childhood neurodevelopmental traits and depressive symptoms across development could be explained by socioenvironmental stressors and emotional dysregulation. The present findings could inform future research aimed at the prevention of depression in youths with neurodevelopmental disorders.

Comparison of bipolar disorder type II and major depressive disorder

OBJECTIVE

Compare patients diagnosed as DSM-5 type II bipolar disorder (BD2) vs. major depressive disorder (MDD).

METHODS

We compared characteristics of 3246 closely and repeatedly evaluated, consenting, adult patient-subjects (n = 706 BD2, 2540 MDD) at a specialty clinic using bivariate methods and multivariable modeling.

RESULTS

Factors more associated with BD2 than MDD included: [a] descriptors (more familial psychiatric, mood and bipolar disorders and suicide; younger at onset, diagnosis and first-treatment; more education; more unemployment; fewer marriages and children; higher cyclothymic, hyperthymic and irritable temperament ratings, lower anxious); [b] morbidity (more hypomanic, mixed or panic first episodes; more co-occurring general medical diagnoses, more Cluster B personality disorder diagnoses and ADHD; more alcohol and drug abuse and smoking; shorter depressive episodes and interepisode periods; lower intake ratings of depression and anxiety, higher for hypomania; far more mood-switching with antidepressants; lower %-time depressed; DMI > MDI course-pattern in BD2; more suicide attempts and violent suicidal behavior); [c] item-scores with intake HDRS₂₁ higher for suicidality, paranoia, anhedonia, guilt, and circadian variation; lower somatic anxiety, depressed mood, insight, hypochondriasis, agitation, and insomnia; and [d] treatment (more lithium, mood-stabilizing anticonvulsants and antipsychotics, less antidepressants and benzodiazepines).

CONCLUSIONS

BD2 and MDD subjects differed greatly in many descriptive, psychopathological and treatment measures, notably including more familial risk, earlier onset, more frequent recurrences and greater suicidal risk with BD2. Such differences can contribute to improving differentiation of the disorders and planning for their treatment.

Practitioner Review: Attention-deficit hyperactivity disorder and autism spectrum disorder - the importance of depression

Young people with neurodevelopmental disorders, such as attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), show high rates of mental health problems, of which depression is one of the most common. Given that depression in ASD and ADHD is linked with a range of poor outcomes, knowledge of how clinicians should assess, identify and treat depression in the context of these neurodevelopmental disorders is much needed. Here, we give an overview of the latest research on depression in young people with ADHD and ASD, including possible mechanisms underlying the link between ADHD/ASD and depression, as well as the presentation, assessment and treatment of depression in these neurodevelopmental disorders. We discuss the implications for clinicians and make recommendations for critical future research in this area.

Differentiation and comorbidity of bipolar disorder and attention deficit and hyperactivity disorder in children, adolescents, and adults: A clinical and nosological perspective

Bipolar Disorder (BD) and Attention Deficit and Hyperactivity Disorder (ADHD) are mental disorders with high degree of lifetime comorbidity. Both BD and ADHD are disorders with onset in childhood and early adolescence. Both disorders are often undiagnosed, misdiagnosed, and sometimes overdiagnosed, leading to high rates of morbidity and disability. The psychiatric and behavioral symptoms associated with ADHD and BD have significant overlap. Albeit the existence of a large body of literature, it is far from being clear whether comorbidity can be explained by the confounding overlap of operationally defined criteria or whether it reflects a genuine comorbidity of two biologically distinct disorders. The aim of this paper is to recognize and/or differentiate the pattern of ADHD across the course of BD from a nosological point of view, focusing on specific clinical and neurobiological dimensions. We found that some critical issues may help to fulfill the purpose of our perspective. We suggest that the relationship between ADHD and BD, based on clinical, developmental, and epidemiological commonalities, can be better clarified using four different scenarios.

Development of bipolar disorder in patients with attention-deficit/hyperactivity disorder: A systematic review and meta-analysis of prospective studies

BACKGROUND

Increasing attention has been recently paid to precursors of bipolar disorder (BD). Symptoms of attention-deficit/hyperactivity disorder (ADHD) have been reported among the most common prodromes of BD. The aim of this study was to estimate the risk of BD in youths affected by ADHD based on prospective studies.

METHODS

A systematic review was conducted according to the PRISMA guidelines. A meta-analysis of single proportions was performed to compute the overall occurrence of BD in ADHD individuals. Binary outcome data were used to calculate risk estimates of BD occurrence in ADHD subjects versus Healthy Controls (HC).

RESULTS

An overall proportion of BD occurrence of 10.01% (95%-confidence interval [CI]: 6.47%-15.19%; I² = 82.0%) was found among 1248 patients with ADHD over 10 prospective studies. A slightly higher proportion was found when excluding one study based on jack-knife sensitivity analysis (11.96%, 95%-CI: 9.15%-15.49%; I² = 54.1%) and in three offspring studies (12.87%, 95%-CI: 8.91%-18.23%). BD occurrence was not significantly associated with mean follow-up duration (p-value = 0.2118). A greater risk of BD occurrence in ADHD versus HC from six studies was found (risk ratio: 8.97, 95%-CI: 4.26-18.87, p-value < 0.0001).

LIMITATIONS

Few prospective studies have been retrieved in our search and most were not specifically aimed at assessing BD in followed-up ADHD patients.

CONCLUSIONS

Greater clinical attention should be paid to ADHD as an early precursor of BD since a substantial proportion of ADHD patients is expected to be diagnosed with BD during the developmental age.

[Early intervention in bipolar affective disorders: Why, when and how]

OBJECTIVES

Bipolar disorder (BD) is a chronic and severe psychiatric disease. There are often significant delays prior to diagnosis, and only 30 to 40 % of patients will experience complete remission. Since BD occurs most often at a young age, the disorder can seriously obstruct future socio-professional development and integration. Vulnerability-stress model of BD is considered to be the result of an interaction between vulnerability genes and environmental risk factors, which leads to the onset of the disorder most often in late adolescence or early adulthood. The clinical "staging" model of BD situates the subject in a clinical continuum of varying degrees of severity (at-risk status, first episode, full-blown BD). Given the demonstrated effectiveness of early intervention in the early stages of psychotic disorder, we posit that early intervention for early stages of BD (i.e. at-risk status and first episode mania or hypomania) would reduce the duration of untreated illness and optimize the chances of therapeutic response and recovery.

METHODS

We conducted a narrative review of the literature to gather updated data on: (1) features of early stages: risk factors, at-risk symptoms, clinical specificities of the first manic episode; (2) early screening: targeted populations and psychometric tools; (3) early treatment: settings and therapeutic approaches for the early stages of BD.

RESULTS

(1) Features of early stages: among genetic risk factors, we highlighted the diagnosis of BD in relatives and affective temperament including as cyclothymic, depressive, anxious and dysphoric. Regarding prenatal environmental risk, we identified peripartum factors such as maternal stress, smoking and viral infections, prematurity and cesarean delivery. Later in the neurodevelopmental course, stressful events and child psychiatric disorders are recognized as increasing the risk of developing BD in adolescence. At-risk symptoms could be classified as "distal" with early but aspecific expressions including anxiety, depression, sleep disturbance, decreased cognitive performance, and more specific "proximal" symptoms which correspond to subsyndromic hypomanic symptoms that increase in intensity as the first episode of BD approaches. Specific clinical expressions have been described to assess the risk of BD in individuals with depression. Irritability, mixed and psychotic features are often observed in the first manic episode. (2) Early screening: some individuals with higher risk need special attention for screening, such as children of people with BD. Indeed, it is shown that children with at least one parent with BD have around 50 % risk of developing BD during adolescence or early adulthood. Groups of individuals presenting other risk factors, experiencing an early stage of psychosis or depressive disorders should also be considered as targeted populations for BD screening. Three questionnaires have been validated to screen for the presence of at-risk symptoms of BD: the Hypomanic Personality Scale, the Child Behavior Checklist-Paediatric Bipolar Disorder, and the General Behavior Inventory. In parallel, ultra-high risk criteria for bipolar affective disorder ("bipolar at-risk") distinguishing three categories of at-risk states for BD have been developed. (3) Early treatment: clinical overlap between first psychotic and manic episode and the various trajectories of the at-risk status have led early intervention services (EIS) for psychosis to reach out for people with an early stage of BD. EIS offers complete biopsychosocial evaluations involving a psychiatric examination, semi-structured interviews, neuropsychological assessments and complementary biological and neuroimaging investigations. Key components of EIS are a youth-friendly approach, specialized and intensive care and client-centered case management model. Pharmaceutical treatments for at-risk individuals are essentially symptomatic, while guidelines recommend the use of a non-antipsychotic mood stabilizer as first-line monotherapy for the first manic or hypomanic episode. Non-pharmacological approaches including psychoeducation, psychotherapy and rehabilitation have proven efficacy and should be considered for both at-risk and first episode of BD.

CONCLUSIONS

EIS for psychosis might consider developing and implementing screening and treatment approaches for individuals experiencing an early stage of BD. Several opportunities for progress on early intervention in the early stages of BD can be drawn. Training first-line practitioners to identify at-risk subjects would be relevant to optimize screening of this population. Biomarkers including functional and structural imaging measures of specific cortical regions and inflammation proteins including IL-6 rates constitute promising leads for predicting the risk of transition to full-blown BD. From a therapeutic perspective, the use of neuroprotective agents such as folic acid has shown particularly encouraging results in delaying the emergence of BD. Large-scale studies and long-term follow-up are still needed to achieve consensus in the use of screening and treatment tools. The development of specific recommendations for the early stages of BD is warranted.

The relationship between attention deficit hyperactivity disorder, bipolarity and mixed features in major depressive patients: Evidence from the BRIDGE-II-Mix Study

OBJECTIVE

This study primarily focused on the relationship between comorbid attention deficit-hyperactivity disorder (ADHD), mixed features and bipolarity in major depressive patients.

METHODS

The sample comprised 2777 patients with Major Depressive Episode (MDE) enrolled in a multicentre, multinational study originally designed to assess different definitions of mixed depression. Socio-demographic, familial and clinical characteristics were compared in patients with (ADHD + ) and without (ADHD-) comorbid ADHD.

RESULTS

Sixty-one patients (2.2%) met criteria for ADHD. ADHD was associated with a higher number of (hypo)manic symptoms during depression. Mixed depression was more represented in ADHD + patients than in ADHD- using both DSM-5 and experimental criteria. Differences were maintained after removing overlapping symptoms between (hypo)mania and ADHD. ADHD in MDE was also associated with a variety of clinical and course features such as onset before the age of 20, first-degree family history of (hypo)mania, past history of antidepressant-induced (hypo)manic switches, higher number of depressive and affective episodes, atypical depressive features, higher rates of bipolarity specifier, psychiatric comorbidities with eating, anxiety and borderline personality disorders.

LIMITATIONS

The study was primarily designed to address mixed features in ADHD, with slightly reduced sensitivity to the diagnosis of ADHD. Other possible diagnostic biases due to heterogeneity of participating clinicians.

CONCLUSIONS

In a sample of major depressive patients, the comorbid diagnosis of current ADHD is associated with bipolar diathesis, mixed features, multiple psychiatric comorbidity and a more unstable course. Further prospective studies are necessary to confirm the possible mediating role of temperamental mood instability and emotional dysregulation in such a complex clinical presentation.

Relationship between bipolar disorder and attention deficit hyperkinetic disorder: An exploratory study

OBJECTIVES

This study aimed to evaluate the impact of comorbid attention deficit hyperkinetic disorder (ADHD) on Bipolar disorder (BD).

METHODS

Patients aged 13-40 years with diagnosis of BD with ADHD (N = 30) were compared to those with BD without ADHD (N = 69) for clinical course, functional outcome and quality of life.

RESULTS

Those with BD + ADHD had significantly lower age of onset of BD (p < 0.001), a significantly higher number of total lifetime episodes (p = 0.002), higher number of lifetime manic episodes (p = 0.008), higher number of hospitalizations (p = 0.004) and higher prevalence of family history of BD as compared to those with BD without ADHD (p = 0.043). BD + ADHD group had poor response to conventional mood stabilizers and significantly higher prescriptions of atypical antipsychotics (p = 0.001) and higher rates of antidepressant-induced switch. Also, BD + ADHD group had significantly lower level of functioning in personal, occupational and social domains and reduced quality of life. In the BD + ADHD group, 40% patients had persistence of ADHD into adulthood. Comorbid current ADHD had more negative impact on the course and outcome of BD, when compared with those with ADHD in the past.

CONCLUSIONS

Comorbid ADHD has negative impact on the course and outcome of BD.

Prevalence and clinical-demographic correlates of hyperhomocysteinemia in inpatients with bipolar disorder in a Han Chinese population

Recent studies have reported that hyperhomocystinemia (HHcy) is highly prevalent in patients with bipolar disorder (BD), placing them at greater risk of cardiovascular disease and possibly serving as a disease biomarker. However, the correlation of HHcy with demographic or clinical parameters is not well known. In this study, we examined the prevalence of HHcy and its association with these parameters in a sample of Chinese BD patients. Fasting plasma homocysteine (Hcy) levels were determined in 198 BD inpatients and 84 healthy controls. HHcy was defined when Hcy concentration exceeded 15.0µmol/L. Affective symptomatology was assessed by the Young Mania Rating Scale, Hamilton Depression Rating Scale and the Clinical Global Impressions severity scale. Compared to healthy controls, BD patients had a significantly higher prevalence (34.85% vs. 19.05%) of HHcy and a higher absolute level of homocysteine. Logistic regression analysis demonstrated that BD patients with HHcy were more likely to be male, have elevated BMI, more frequent treatment on lithium but less on valproate. These results suggest that Chinese inpatients with bipolar disorder have a higher rate of HHcy than the general population, and those at greatest risk are male, have an elevated BMI, and take more lithium but less valproate therapy.