the hedgehog report
Booze
Jessica Weafer; Mark T. Fillmore & Richard Milich. (2009) “Increased sensitivity to the disinhibiting effects of alcohol in adults with ADHD.” Experimental and Clinical Psychopharmacology 17(2): 113-121.
In conclusion, the present findings demonstrate that adults with ADHD exhibited a deficit in inhibitory control compared with healthy controls as measured by the cued go/no-go task, and that this deficit was exacerbated in response to alcohol. The group differences in impairment of inhibitory control were evident in the valid cue condition when overall levels of disinhibition were low. The current study suggests that adults with ADHD exhibit an increased sensitivity to alcohol impairment of basic acts of inhibitory control, and this may contribute to the high incidence of impulsive behaviors observed in individuals with this disorder, especially in response to alcohol. Additional work is needed to examine the potential behavioral consequences of an increased sensitivity to the acute disinhibiting effects of alcohol in adults with ADHD, including increased alcohol consumption and risky behavior while intoxicated.
Time
Gilden, David L. & Marusich, Laura R.. (2009) “Contraction of time in attention-deficit hyperactivity disorder.” Neuropsychology 23(2): 265 - 269.
The notion that time perception might be altered by ADHD is supported by neuroimaging evidence of volumetric reductions (Castellanos et al., 2002; Valera, Faraone, Murray, & Seidman, 2007) in areas known to control and regulate timing: prefrontal cortex (Mangels, Ivry, & Shimizu, 1998; Smith, Taylor, Lidzba, & Rubia, 2003) and cerebellum (Ivry & Spencer, 2004; Mangels et al., 1998).
They did a pilot study where ADHD and normal people did a rhythm-keeping task at 60 bpm, 40 bpm (the slowest most metronomes will count), and 30 bpm. At each tempo:
participants slapped the drum with their dominant hand in time with a synchronizing signal for 16 beats and then continued without the signal for another 3 minutes. To prevent counting, participants drummed while reading aloud from a non-technical book review printed in large clear type.
Ok, so I doubt I could read and beat a drum at the same time, period. Anyway, what they found was that at the fastest tempo, ADHD people were actually more consistent and accurate than the normal people. At 40 bpm, the ADHD people totally lost touch with the beat, while normal people performed the same as they did at 60 bpm. At 30 bpm, everyone sucked, but the ADHD people had slightly better sense of timing. This is why metronomes don’t go that slow. Which doesn’t really say anything at this point, but I’m certainly interested in this line of research, given my absolute lack of sense of time most of the time (but uncanny ability in some situations to know exactly when the timer is about to go off…)
dopamine, or why I like bupropion
Swen Hesse; Olaf Ballaschke; Henryk Barthel & Osama Sabri. (2009) “Dopamine transporter imaging in adult patients with attention-deficit/hyperactivity disorder.” Psychiatry Research: Neuroimaging 171(2): 120-128.
The aim of this study was to provide in vivo evidence for the hypothesis that dopaminergic neurotransmission is altered in adult patients with attention-deficit/hyperactivity disorder (ADHD). We used high-resolution brain-dedicated single-photon emission computed tomography and the dopamine transporter (DAT) marker [123I]FP-CIT in 17 adult treatment-naïve ADHD patients and 14 age-matched controls. Magnetic resonance imaging-based region of interest analysis was performed to quantify the DAT availability (expressed as a ratio of specific to non-displaceable binding, V3″) in the striatum. Additionally, the specific radiotracer binding was assessed in the thalamus and the midbrain/brainstem regions (reflecting also the availability of the serotonin transporter to which [123I]FP-CIT binds with moderate affinity). In the striatal areas of the ADHD patients, a significantly reduced specific tracer binding was found (V3″: 5.18 ± 0.98; controls 6.36 ± 1.34). In contrast, the specific [123I]FP-CIT binding did not differ from controls in the thalamus and midbrain/brainstem areas. These data indicate a reduced dopaminergic but not serotonergic transmitter reuptake function in adult ADHD. Further studies will have to deal with the question of whether these findings have the potential to influence treatment decisions in this complex disorder.
coaching: apparently effective
Joyce A Kubik. (2009) “Efficacy of ADHD Coaching for Adults With ADHD.” Journal of Attention Disorders (early view)
sleep, or i should be in bed right now
Yuri E. Rybak; Heather E. McNeely; Bronwyn E. Mackenzie; Umesh R. Jain & Robert D. Levitan. (2007) “Seasonality and circadian preference in adult attention-deficit/hyperactivity disorder: clinical and neuropsychological correlates.” Comprehensive Psychiatry 48(6): 562-571.
Based on the morningness-eveningness questionnaire, which assesses circadian preference 11 (40.7\%, N = 27) subjects were designated as evening types and only 5 (18.5\%) as morning types, a distribution highly discrepant with general population studies. Later circadian preference, independent of seasonality, was strongly correlated with both self-reported symptoms of {ADHD} and neuropsychological deficits, including impulsive responding and poor target discrimination.
S. Kooij. (2009) “S01-01 On rhythms and seasons: Associations between ADHD, eveningtypes, seasonal mood changes, and health.” European Psychiatry 24(Supplement 1): S10.
The majority of the adults with ADHD have chronic difficulty to go to bed on time. This leads to a shorter sleep duration and daytime sleepiness that may aggravate the inattention problems of ADHD. This sleep pattern is also known as a delayed sleepphase, and the patients as ‘eveningtypes’.
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