Posts Tagged ‘ADHD’

“Owls” more likely to have ADHD?

07/12/2011 6 comments
Is there any relationship between chronotype and Attention-deficit hyperactivity disorder (ADHD) symptoms? Are evening oriented individuals more likely to have ADHD? This was the main question posed in a (relatively) recent article by Caci and colleagues.

ADHD is the most common neurodevelopmental disorder (Faraone et al., 2003) and affects about 3–6% of children (Tannock 1998). ADHD is defined by either an attentional dysfunction, hyperactive/impulsive behaviour or both (DSM-IV; American Psychiatric Association, 1994). Therefore, the diagnosis of ADHD has three subtypes: the Inattentive subtype (ADHD/IA), which is characterised by significant levels of inattention but subthreshold levels of hyperactive/ impulsive symptoms, the Hyperactive/Impulsive subtype (ADHD/HI), which is defined by hyperactivity/ impulsivity but not of inattention symptoms, and the Combined Inattentive-Hyperactive/Impulsive subtype (ADHD/C), which is characterised by maladaptive levels of both symptom clusters.

Morningness is a stable characteristic which reflects the phase of circadian system. It is a continuum with evening types at one end and morning types on the other. Previous studies have found that the evening orientation might be a risk factor for various disorders including depression and personality disorders. Morningness is also a heritable trait (Vink, Groot, Kerkhof, & Boomsma, 2001) and determined by genetic factors (Mishima, Tozawa, Satoh, Saitoh, & Mishima, 2005). Impulsivity and novelty seeking, two characteristics associated with particular ADHD subtypes are negatively related to morningness. Specifically, evening oriented individuals often score higher on tests assessing those traits. In addition to that, there is evidence that morningness is implicated in the variation of performance (Natale, Alzani, & Cicogna, 2003). Variability in various cognitive tasks is a common finding in many studies examining individuals with ADHD. Individuals with ADHD have also been found to experience a number of sleep related disorders such as sleep-onset difficulties, agitated sleep, and a higher number of nocturnal awakings.

Caci et al. examined the relationship between morningness and ADHD. Their hypothesis was that adults suspected of having ADHD are more evening oriented than are adults without ADHD. They recruited 354 participants and assessed their scores in the Composite Scale of Morningness (CSM), a measure of morningness, and the Adult Self-Report Scale v1.1 (ASRS), a self-reported questionnaire used for screening of ADHD in adults. ASRS includes two subscales for inattention and hyperactivity symptoms. This allowed Caci et al to examine the relationship between possible ADHD subtypes and morningness.

The results of the study confirmed the hypothesis; participants with higher scores on the ASRS reported having an evening orientation. The effect was stronger in participants with higher scores on the subscale of inattention. No correlation was found between hyperactivity and morningness. This provides evidence for the existence of different endophenotypes in ADHD. Since the sample used in this study consisted of healthy volunteers, it would be interesting to try to replicate this finding in diagnosed individuals with ADHD.

PS: After writing this post, I realised there’s a new study published in Nature by Baird et al. (2011) that examines endocrine and molecular levels of circadian rhythms in ADHD and seems to confirm the morningness hypothesis proposed by Caci et al. According to this paper, adult ADHD is accompanied by significant changes in the circadian system. I might write a post about it in the near future.


ResearchBlogging.orgCaci H, Bouchez J, & Baylé FJ (2009). Inattentive symptoms of ADHD are related to evening orientation. Journal of attention disorders, 13 (1), 36-41 PMID: 19387003

So… who likes sports?

30/11/2011 1 comment

There’s no doubt that watching sports is a very popular pastime.

In 2010 alone, there were over 40,500 h of live sporting events on broadcast and cable TV (Neilsen Company, 2011)

However, little is know about the personality  traits and the identity of people who like watching sports*.

Appelbaum and colleagues gathered  broad demographic, physiological, clinical, psychological, and pastime-preference information from a sample of 293 individuals to see what factors most reliably predicted sport spectating habits. First, they examined possible relationships between watching sports and physiological measures. Saliva was collected and baseline testosterone and cortisol levels were measured. Moreover, 2D:4D digit ratio was calculated for each individual. This measurement is a proxy of prenatal androgen exposure and has been shown to correlate with particular disorders. Secondly, they administered self-report scales looking at ADHD (Jasper/Goldberg adult ADD/ADHD questionnaire) and autism traits (AQ; Autism Spectrum Quotient). Furthermore, they investigated the relationship between sports spectating and personality traits. The NEO personality inventory (NEO-PI-R), which measures the “BigFive” personality traits, and the Barratt Impulsivity Scale (BIS-11) were used. Finally, Appelbaum et al. asked their participants about the pastime activities. The pastime involvement questionnaire asked participants how many hours a week they spend on a number of activities such as reading, playing sports, watching television and movies, and listening to music.

As expected gender and age significantly accounted for the variability in the results. Young males reported spending more time watching sports.  High levels of sports spectating were correlated with higher levels of extraversion, excitement seeking and gregariousness on the personality questionnaires. The participants who reported spending more hours watching sports also engaged more in specific pastime activities, such as participating in sports and exercise, watching TV/movies, and playing video games. No differences were observed in the self-report scales. More specifically, no differences in ADHD or autism symptoms were found between people who watch sports and people who don’t. Likewise, the authors didn’t find any relationship between digit ratio and sports watching.

No relationship was found between baseline concentrations of cortisol or testosterone and sports spectating. This came as a surprise to the authors who list a number of previous studies that identified higher concentrations of testosterone and cortisol in people who like sports. Now, before jumping to conclusions, take into account that the sport spectators in this study is not your average sports fan! Previous literature has identified two related concepts; fans and spectators. Even though those groups have some overlapping qualities, there are some key differences.

…a fan is typically associated with an emotional link to a sport or team, while a spectator is a more neutral descriptor of an individual who consumes sports (Wann & Dolan, 2001).

In this study, they were interested only in sports spectators (defined by the hours they spend watching sports). This could possibly explain why no relationship was found between sports watching and cortisol concentration.

Also, I think that there must be differences between spectators of different types of sports (e.g. rugby, tennis, snooker). The authors didn’t examined this, but it’d be interesting to see a study looking at differences in sports preferences between people who enjoy watching sports.

ResearchBlogging.orgGregory Appelbaum, L., Cain, M., Darling, E., Stanton, S., Nguyen, M., & Mitroff, S. (2011). What is the identity of a sports spectator? Personality and Individual Differences DOI: 10.1016/j.paid.2011.10.048

* Academics are probably not very keen on sports?

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