Pleiotropic effects of Chr15q25 nicotinic gene cluster and the relationship between smoking, cognition and ADHD.

Polymorphisms in the CHRNA5-CHRNA3-CHRNB4 gene cluster (Chr15q25) have been robustly associated with nicotine dependence, including genome-wide studies, as well as with cognitive and neuropsychological measures. In addition, cognitive processes can be influenced by nicotine use through nicotinic acetylcholine receptors (nAChRs). Here, we evaluated the effect of polymorphisms in CHRNA5-CHRNA3-CHRNB4 gene cluster and their interaction with tobacco smoking status on cognition in patients with Attention Deficit/Hyperactivity Disorder (ADHD).

Severity but not comorbidities predicts response to methylphenidate in adults with attention-deficit/hyperactivity disorder: results from a naturalistic study.

Although the identification of reliable predictors of methylphenidate response in adults with attention-deficit/hyperactivity disorder (ADHD) is necessary to guide treatment decisions, very few data exist on this issue. Here, we assessed the predictors of clinical response to immediate-release methylphenidate hydrochloride (IR-MPH) in a naturalistic setting by analyzing the influence of demographic factors, severity, and a wide range of comorbid psychiatric disorders. Two hundred fifty adult patients with ADHD were evaluated and completed a short-term treatment with IR-MPH.

ADHD diagnosis may influence the association between polymorphisms in nicotinic acetylcholine receptor genes and tobacco smoking.

Polymorphisms in the CHRNA5-CHRNA3-CHRNB4 gene cluster have been shown to be involved in tobacco smoking susceptibility. Considering that attention deficit/hyperactivity disorder (ADHD) not only increases the risk but may also influence the molecular mechanisms of tobacco smoking, we analyzed the association between polymorphisms in the nicotinic acetylcholine receptor genes and tobacco smoking among individuals with or without ADHD. The sample included 1,118 subjects divided into four groups according to smoking status and ADHD diagnosis.

Could comorbid bipolar disorder account for a significant share of executive function deficits in adults with attention-deficit hyperactivity disorder?

Objective: The frequent comorbidity between attention-deficit hyperactivity disorder (ADHD) and bipolar disorder (BD) represents a challenge for disentangling specific impairments of each disorder in adulthood. Their functional impairments seem to be mediated by executive function deficits. However, little is known about the extent to which each executive function deficit might be disorder specific or explained by the comorbidity.

Does age of onset of impairment impact on neuropsychological and personality features of adult ADHD?

The consideration of age of onset of impairment as part of the ADHD diagnosis is controversial and has been a revisited issue with the emergence of the new classifications in Psychiatry. The aim of this study is to compare patients with early and late onset of ADHD impairment in terms of neuropsychological and personality characteristics. Adult patients with ADHD (n = 415) were evaluated in the ADHD outpatient program at Hospital de Clínicas de Porto Alegre, Brazil.

The role of a lifetime history of oppositional defiant and conduct disorders in adults with ADHD: implications for clinical practice.

Introduction: Attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD) are frequently co-occurring disorders in children and adolescents. However, their clinical status among adults is still under discussion. This study analyzes how the current clinical presentation of adult ADHD might be influenced by a lifetime history of CD and ODD.

Cognitive deficits in adults with ADHD go beyond comorbidity effects.

Objective: This study addresses if deficits in cognitive, attention, and inhibitory control performance in adults with ADHD are better explained by the disorder itself or by comorbid conditions.

Method: Adult patients with ADHD (n = 352) and controls (n = 94) were evaluated in the ADHD program of a tertiary hospital. The diagnostic process for ADHD and comorbidities was based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.