Common psychiatric and metabolic comorbidity of adult attention-deficit/hyperactivity disorder: A population-based cross-sectional study

Suicidal and non-suicidal self-injurious behaviour in patients with bipolar disorder and comorbid attention deficit hyperactivity disorder after initiation of central stimulant treatment: a mirror-image study based on the LiSIE retrospective cohort

BACKGROUND

Currently, our understanding regarding treatment of adult attention deficit hyperactivity disorder (ADHD) co-occurring with bipolar disorder (BD) remains limited. The aim of this study was to evaluate the impact of central stimulant (CS) treatment on suicidal and non-suicidal self-injurious behaviour in patients with a pre-existing diagnosis of BD or schizoaffective disorder (SZD). Specifically, we tested the hypothesis that CS treatment significantly decreased the number of suicide attempts and non-suicidal self-injury events.

METHODS

A mirror-image study in patients with a dual diagnosis of BD or SZD and ADHD, comparing suicide attempts and non-suicidal self-injury events within 6 months and 2 years before and after CS initiation. This study was part of a retrospective cohort study (LiSIE) into effects and side-effects of lithium for maintenance treatment of BD as compared with other mood stabilisers.

RESULTS

Of 1564 eligible patients, 206 patients met the inclusion criteria. Within the 6 months after CS initiation, suicide attempts and non-suicidal self-injury events decreased significantly, both in terms of numbers of patients having such events (p = 0.013) and numbers of events experienced (p = 0.004). These effects were preserved 2 years after CS initiation.

CONCLUSIONS

CS treatment may reduce the risk of suicide attempts and non-suicidal self-injury events in patients with a dual diagnosis of BD or SZD and ADHD. Based on our findings, clinicians should not withhold CS treatment from patients with concomitant ADHD for fear of deterioration of the underlying BD. However, to minimise the risk of manic episodes concomitant mood stabiliser treatment and close monitoring remains warranted.

Patterns of Psychiatric Comorbidity and Genetic Correlations Provide New Insights Into Differences Between Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) share common genetic factors but seem to have specific patterns of psychiatric comorbidities. There are few systematic studies on adults; therefore, we compared psychiatric comorbidities in adults with these two neurodevelopmental disorders using population-based data and analyzed their genetic correlations to evaluate underlying factors.

METHODS

Using data from Norwegian registries, we assessed patterns of psychiatric disorders in adults with ADHD (n = 38,636; 2.3%), ASD (n = 7528; 0.4%), and both diagnoses (n = 1467; 0.1%) compared with the remaining adult population (n = 1,653,575). We calculated their prevalence ratios (PRs) and differences using Poisson regression, also examining sex-specific relations. Genetic correlations (r_g) among ADHD, ASD, and the examined psychiatric disorders were calculated by linkage disequilibrium score regression, exploiting summary statistics from relevant genome-wide association studies.

RESULTS

For all psychiatric comorbidities, PRs differed between ADHD and ASD. Associations were strongest in individuals with ADHD and ADHD+ASD for most comorbidities, in both men and women. The relative prevalence increase of substance use disorder was three times larger in ADHD than in ASD (PR_ADHD, 6.2; 95% confidence interval [CI], 6.1-6.4; PR_ASD, 1.9; 95% CI, 1.7-2.2; p < .001); however, the opposite was true for schizophrenia (PR_ASD, 13.9; 95% CI, 12.7-15.2; PR_ADHD, 4.4; 95% CI, 4.1-4.7; p < .001). Genetic correlations supported these patterns but were significantly different between ADHD and ASD only for the substance use disorder proxies and personality traits (p < .006 for all).

CONCLUSIONS

Adults with ADHD, ASD, or both ADHD and ASD have specific patterns of psychiatric comorbidities. This may partly be explained by differences in underlying genetic factors.

Prevalence of ADHD in Accident Victims: Results of the PRADA Study

Background: Recent research has shown an increased risk of accidents and injuries in ADHD patients, which could potentially be reduced by stimulant treatment. Therefore, the first aim of our study was to evaluate the prevalence of adult ADHD in a trauma surgery population. The second aim was to investigate accident mechanisms and circumstances which could be specific to ADHD patients, in comparison to the general population. Methods: We screened 905 accident victims for ADHD using the ASRS 18-item self-report questionnaire. The basic demographic data and circumstances of the accidents were also assessed. Results: Prevalence of adult ADHD was found to be 6.18% in our trauma surgery patient sample. ADHD accident victims reported significantly higher rates of distraction, stress and overconfidence in comparison to non-ADHD accident victims. Overconfidence and being in thoughts as causal mechanisms for the accidents remained significantly higher in ADHD patients after correction for multiple comparison. ADHD patients additionally reported a history of multiple accidents. Conclusion: The majority of ADHD patients in our sample had not previously been diagnosed and were therefore not receiving treatment. The results subsequently suggest that general ADHD screening in trauma surgery patients may be useful in preventing further accidents in ADHD patients. Furthermore, psychoeducation regarding specific causal accident mechanisms could be implemented in ADHD therapy to decrease accident incidence rate.

The Role of the Gut-Brain Axis in Attention-Deficit/Hyperactivity Disorder

Genetic and environmental factors play a role in the cause and development of attention-deficit/hyperactivity disorder (ADHD). Recent studies have suggested an important role of the gut-brain axis (GBA) and intestinal microbiota in modulating the risk of ADHD. Here, the authors provide a brief overview of the clinical and biological picture of ADHD and how the GBA could be involved in its cause. They discuss key biological mechanisms involved in the GBA and how these may increase the risk of developing ADHD. Understanding these mechanisms may help to characterize novel treatment options via identification of disease biomarkers.

Attention Deficit/Hyperactivity, the Metabolic Syndrome, and Type 2 Diabetes

PURPOSE OF REVIEW

To present current data on the coexistence of attention deficit hyperactivity disorder (ADHD) and the metabolic syndrome and type 2 diabetes mellitus in adults and children and to discuss possible mechanisms.

RECENT FINDINGS

Emerging data suggest that risk factors for obesity and insulin resistance such as diabetes during pregnancy and intrauterine growth failure may also have a role in the development of ADHD. Furthermore, ADHD and obesity share lifestyle factors, such as abnormal eating patterns, binge eating, and a sedentary lifestyle. ADHD is a risk factor for components of the metabolic syndrome, particularly obesity and type 2 diabetes mellitus, and also hypertension, both in adults and youth. Associations of ADHD with obesity, diabetes, and hypertension have been ascertained, and various mechanisms have been proposed. Research is needed to decipher the shared genetic, pharmacological, and lifestyle risk factors. Individuals with ADHD should be treated as a high-risk group for cardiometabolic complications.

ADGRL3 (LPHN3) variants predict substance use disorder

Genetic factors are strongly implicated in the susceptibility to develop externalizing syndromes such as attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder, conduct disorder, and substance use disorder (SUD). Variants in the ADGRL3 (LPHN3) gene predispose to ADHD and predict ADHD severity, disruptive behaviors comorbidity, long-term outcome, and response to treatment. In this study, we investigated whether variants within ADGRL3 are associated with SUD, a disorder that is frequently co-morbid with ADHD. Using family-based, case-control, and longitudinal samples from disparate regions of the world (n = 2698), recruited either for clinical, genetic epidemiological or pharmacogenomic studies of ADHD, we assembled recursive-partitioning frameworks (classification tree analyses) with clinical, demographic, and ADGRL3 genetic information to predict SUD susceptibility. Our results indicate that SUD can be efficiently and robustly predicted in ADHD participants. The genetic models used remained highly efficient in predicting SUD in a large sample of individuals with severe SUD from a psychiatric institution that were not ascertained on the basis of ADHD diagnosis, thus identifying ADGRL3 as a risk gene for SUD. Recursive-partitioning analyses revealed that rs4860437 was the predominant predictive variant. This new methodological approach offers novel insights into higher order predictive interactions and offers a unique opportunity for translational application in the clinical assessment of patients at high risk for SUD.

Situating adult attention-deficit/hyperactivity disorder in the externalizing spectrum: Etiological, diagnostic, and treatment considerations

Adult attention-deficit/hyperactivity disorder (ADHD) has a population prevalence of 5%. However, its prevalence is much higher in mental health and substance use treatment settings. It is associated with significant physical and psychiatric morbidity, as well as social, occupational, and legal consequences. Adult ADHD is considered to be a part of the externalizing spectrum with which it shares both homotypic comorbidity and heterotypic continuity across the lifespan. This is attributable to a shared genetic basis, which interacts with environmental risk factors such as nutritional deficiencies and psychosocial adversity to bring about epigenetic changes. This is seen to result in a lag in brain maturation particularly in the areas of the brain related to executive functioning (top-down regulation) such as the prefrontal and cingulate cortices. This delay when coupled with impairments in reward processing, leads to a preference for immediate small rewards and is common to externalizing disorders. Adult ADHD is increasingly understood to not merely be associated with the classically described symptoms of hyperactivity, impulsivity and inattention, but also issues with motivation, emotional recognition and regulation, excessive mind wandering, and behavioral self-regulation. These symptoms are also observed in other disorders which overlap with the externalizing spectrum such as oppositional defiant disorder, conduct disorder, antisocial and borderline personality disorder. It is therefore important to develop both broad-based and specific interventions to be able to target these deficits which can reduce the burden and improve outcomes.