Effects of methylphenidate on mismatch negativity and P3a amplitude of initially psychostimulant-naïve, adult ADHD patients.

BACKGROUND: Deficient information processing in ADHD theoretically results in sensory overload and may underlie the symptoms of the disorder. Mismatch negativity (MMN) and P3a amplitude reflect an individual's detection and subsequent change in attention to stimulus change in their environment. Our primary aim was to explore MMN and P3a amplitude in adult ADHD patients and to examine the effects of methylphenidate (MPH) on these measures. METHODS: Forty initially psychostimulant-naïve, adult ADHD patients without comorbid ASD and 42 matched healthy controls (HC) were assessed with an MMN paradigm at baseline. Both groups were retested after 6 weeks, in which patients were treated with MPH. RESULTS: Neither significant group differences in MMN nor P3a amplitude were found at baseline. Although 6-week MPH treatment significantly reduced symptomatology and improved daily functioning of the patients, it did not significantly affect MMN amplitude; however, it did significantly reduce P3a amplitude compared to the HC. Furthermore, more severe ADHD symptoms were significantly associated with larger MMN amplitudes in the patients, both at baseline and follow-up. CONCLUSION: We found no evidence for early information processing deficits in patients with ADHD, as measured with MMN and P3a amplitude. Six-week treatment with MPH decreased P3a but not MMN amplitude, although more severe ADHD-symptoms were associated with larger MMN amplitudes in the patients. Given that P3a amplitude represents an important attentional process and that glutamate has been linked to both ADHD and MMN amplitude, future research should investigate augmenting MPH treatment of less responsive adults with ADHD with glutamatergic antagonists.

Effects of methylphenidate on subjective sleep parameters in adults with ADHD: a prospective, non-randomized, non-blinded 6-week trial.

OBJECTIVE: Methylphenidate is a first-line treatment for ADHD; its contribution to sleep problems in adult ADHD is currently unclear. This study investigates (a) subjective sleep disturbances in a group of initially stimulant medication-naïve adults with ADHD and (b) reported changes in sleep problems after 6 weeks of methylphenidate treatment. METHOD: A prospective, non-randomized, non-blinded, 6-week follow-up study utilising a self-report measure. RESULTS: We found (1) a large difference in reported sleep quality between methylphenidate medication-naïve patients and controls at baseline, (2) a marked improvement in patients after methylphenidate medication, and (3) largest improvement for patients with the poorest reported sleep at baseline. CONCLUSION: The study indicates that treatment with methylphenidate increases subjective sleep quality for at least some adults with ADHD.

Effects of methylphenidate on sensory and sensorimotor gating of initially psychostimulant-naïve adult ADHD patients.

Deficient information processing in ADHD theoretically results in sensory overload, which in turn may underlie its symptoms. If this sensory overload is caused by deficient filtering of environmental stimuli, then one would expect finding deficits in P50 gating and prepulse inhibition of the startle reflex (PPI). Previous reports on these measures in ADHD have shown inconsistent findings, which may have been caused by either medication use or comorbidity (e.g. ASD). The primary aim of this study was therefore to explore P50 suppression and PPI in adult, psychostimulant-naïve patients with ADHD without major comorbidity, and to examine the effects of 6 weeks treatment with methylphenidate (MPH) on these measures. A total of 42 initially psychostimulant-naive, adult ADHD patients without major comorbidity and 42 matched healthy controls, were assessed for their P50 gating, PPI, and habituation/sensitization abilities at baseline and after 6 weeks of treatment with methylphenidate. Although six weeks of treatment with MPH significantly reduced symptomatology as well as improved daily life functioning in our patients, it neither significantly affected PPI, P50 suppression nor sensitization, but habituation unexpectedly decreased. The absence of PPI and P50 suppression deficits in our patients in the psychostimulant-naïve state indicates no gating deficits. In turn, this suggests that the difficulties to inhibit distraction of attention by irrelevant stimuli that many patients with (adult) ADHD report, have a different origin than the theoretical causes of sensory overload frequently reported in studies on patients with schizophrenia.

Visual attention in adults with attention-deficit/hyperactivity disorder before and after stimulant treatment.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder which frequently persists into adulthood. The primary goal of the current study was to (a) investigate attentional functions of stimulant medication-naïve adults with ADHD, and (b) investigate the effects of 6 weeks of methylphenidate treatment on these functions. METHODS: The study was a prospective, non-randomized, non-blinded, 6-week follow-up design with 42 stimulant medication-naïve adult patients with ADHD, and 42 age and parental education-matched healthy controls. Assessments included measures of visual attention, based on Bundesen's Theory of Visual Attention (TVA), which yields five precise measures of aspects of visual attention; general psychopathology; ADHD symptoms; dyslexia screening; and estimates of IQ. RESULTS: At baseline, significant differences were found between patients and controls on three attentional parameters: visual short-term memory capacity, threshold of conscious perception, and to a lesser extent visual processing speed. Secondary analyses revealed no significant correlations between TVA parameter estimates and severity of ADHD symptomatology. At follow-up, significant improvements were found specifically for visual processing speed; this improvement had a large effect size, and remained when controlling for re-test effects, IQ, and dyslexia screen performance. There were no significant correlations between changes in visual processing speed and changes in ADHD symptomatology. CONCLUSIONS: ADHD in adults may be associated with deficits in three distinct aspects of visual attention. Improvements after 6 weeks of medication are seen specifically in visual processing speed, which could represent an improvement in alertness. Clinical symptoms and visual attentional deficits may represent separate aspects of ADHD in adults.

Delay Aversion and Executive Functioning in Adults With Attention-Deficit/Hyperactivity Disorder: Before and After Stimulant Treatment.

Background: Attention deficit hyperactivity disorder is a heterogeneous disorder, associated with deficits in motivation (e.g., delay aversion) and cognition. Methylphenidate is recommended as a first line treatment for attention deficit hyperactivity disorder symptoms, but little is known about its nonacute effects on motivational and cognitive deficits, particularly in adults with attention deficit hyperactivity disorder. Methods: We utilized a prospective, non-randomized, non-blinded, 6-week follow-up design with 42 initially stimulant medication-naïve adult patients with moderate to severe attention deficit hyperactivity disorder, and 42 age- and parental education-matched healthy controls. Delay aversion and executive functioning were assessed with 2 questionnaires and 5 performance-based tests. Results: At baseline, patients and controls differed significantly on performance-based measures (moderate to large effect sizes), and self-report of delay aversion and executive functioning (very large effect sizes). Treatment with methylphenidate medication (mean dose 65.54 mg/d, SD=10.39) was not associated with improvements in performance-based measures of delay aversion and executive functioning compared to controls, although improvements in self-report executive functioning and delay aversion were found. Self-reported delay aversion was most consistently associated with ADHD symptomatology at baseline and after medication. Conclusion: Methylphenidate treatment does not have an effect on performance-based measures of delay aversion and executive functioning, but may have significant effects on self-reported delay aversion and executive functioning. The latter finding should be interpreted cautiously, given the subjective nature of these measures and design limitations. Self-reported delay aversion is most consistently associated with attention deficit hyperactivity disorder symptomatology.

[Prevalence of dementia or other form of organic brain disorder on a geriatric psychiatry ward]. / Forekomst af demens eller anden form for erhvervet hjernesygdom på en gerontopsykiatrisk afdeling.

INTRODUCTION: The prevalence of dementia in various geriatric psychiatry settings has previously been investigated and been found to lie between 15.2% and 61%. The present study investigated the percentage of patients with "organic brain disorder" [OBD] (dementia, acquired brain injury or other brain disease) in one geriatric psychiatric department in Copenhagen, Denmark. MATERIALS AND METHODS: The journals of all patients admitted to the geriatric psychiatric department (locked ward, open ward, and day hospital) in 2002 were studied in order to find evidence of (a) psychiatric discharge diagnosis of OBD in 2002 (b) previous diagnosis of OBD (c) the basis of these diagnoses. RESULTS: 130 patients were admitted at least once in 2002. 33.1% had an OBD diagnosis at discharge, whilst a further 18.4% had documented evidence of previously diagnosed OBD and/or assessments supporting the presence of OBD. Effects of gender and age at first admission were found on discharge diagnosis. CONCLUSION: There is evidence that over half of the patients admitted to the geriatric psychiatry department in this study had an OBD, which is higher than the percentage of patients who were discharged with this diagnosis. The possible consequences of findings and the drawbacks of the study are discussed.