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Attention deficit/hyperactivity disorder (ADHD) is the most prevalent childhood psychiatric condition. It frequently persists into adulthood and can have serious health and other adverse consequences. The majority of previous adult ADHD studies have focused on young adults so that relatively little is known about ADHD symptoms and their effects in mid and(More)
A major concern with the vast literature associating the highly polymorphic 48 bp VNTR in exon III of the human dopamine receptor D4 gene (DRD4) with various behavioral phenotypes is the lack of concordance between studies. Part of the problem arises from the absence of a universally accepted scheme for pooling the large number of low frequency genotypes(More)
Attention Deficit/Hyperactivity Disorder (ADHD) is a common neuropsychiatric disorder that has not been well studied in older adults. In this study we examined relationships between ADHD symptoms and cognitive ability and compared them between middle-age (MA; 48-52 years) and older-age (OA; 68-74 years) adults sampled from the same population. ADHD, mood(More)
Genetic differences play a significant role in generating individual differences in cognitive abilities. Studies have linked common polymorphisms (valine to methionine substitution; VAL/MET) in the catechol-O-methyltransferase (COMT) and brain-derived neurotrophic factor (BDNF) to cognitive differences between individuals. However, not all studies support(More)
We examined the association of 28 single nucleotide polymorphisms (SNPs), previously associated with dementia or cognitive performance, with tests assessing episodic memory, working memory, vocabulary, and perceptual speed in 1689 nondemented older Australians of European ancestry. In addition to testing each variant individually, we assessed the collective(More)
Nicotine, the primary addictive component of tobacco, affects the mammalian brain. Smokers' brains have smaller cortical grey matter volumes and/or lower densities compared with non-smokers'. Differences in subcortical structures like the striatum are however, less clear. A high concentration of nicotinic receptors makes the striatum a potential target for(More)
Most individuals successfully maintain psychological well-being even when exposed to trauma or adversity. Emotional resilience or the ability to thrive in the face of adversity is determined by complex interactions between genetic makeup, previous exposure to stress, personality, coping style, availability of social support, etc. Recent studies have(More)
Neuroimaging studies of attention-deficit/hyperactivity disorder (ADHD) have revealed deviations of the corpus callosum in children and adolescents. However, little is known about the link between callosal morphology and symptoms of inattention or hyperactivity in adulthood, especially later in life. Here, we investigated in a large population-based sample(More)
OBJECTIVE ADHD is a lifelong condition, but it remains understudied in older adults. We examined the effects of ADHD-related inattention and hyperactivity symptoms on cognitive abilities in middle-age adults. METHOD ADHD symptoms and cognitive abilities were accessed in a population-based sample (N = 2,091). Multiple regression analyses evaluated the(More)
OBJECTIVE We investigated whether volumetric differences in ADHD-associated brain regions are related to current symptoms of inattention and hyperactivity in healthy middle-aged adults and whether co-occurring anxiety/depression symptoms moderate these relationships. METHOD ADHD Self-Report Scale and Brief Patient Health Questionnaire were used to assess(More)