ADHD Flashcards
what are externalising disorders?
problem behaviours that includes several clinically recognised disorders such as attention-deficit/hyperactivity disorder (ADHD), conduct disorder (CD), and oppositional defiant disorder (ODD)
issue with externalising orders grouping?
By grouping ADHD, CD, and ODD under one label as externalising disorders, the commonalities of these disorders are highlighted, however, some of their important differences are usually de-emphasised (Mullin & Hinshaw, 2007).
what does ADHD stand for?
Attention-deficit/hyperactivity disorder
what is ADHD characterised by
pervasive behavioural symptoms of hyperactivity, impulsivity and inattention, beginning in childhood.
rates of ADHD
In the UK it is reported that 8% of children are diagnosed with ADHD (Alloway et al., 2010).
gender occurance of ADHD
The disorder commonly occurs amongst boys than girls; boys are 6-9% more likely to be diagnosed with ADHD.
who made the first account of ADHD and what did they call it?
= Crichton (1798)
Called it mental restlessness described as “the incapacity of attending with a necessary degree of constancy to any one object”
DMS-V diagnosis of ADHD changes
- Adults and teenagers can officially be diagnosed
- Earliest symptoms identified at age 12 years (instead of 7)
- Subtypes are now referred to as ‘presentations’
- Mild, moderate and severe levels of ADHD, depending on symptoms
- Main difference from DSM IV-TR - Can be diagnosed with Autism Spectrum Disorder (ASD)
different presentations of ADHD
Predominantly inattentive presentation- struggle with impulse control
Predominantly hyperactive/impulsive presentation- often unofficially referred to as ADD- have difficulty paying attention
Combined presentation- significant problems in both areas.
severity of ADHD differences
- Mild: Few, if any, symptoms in excess of those required to make the diagnosis are present, and symptoms result in only minor functional impairments.
- Moderate: Symptoms or functional impairment between “mild” and “severe” are present.
- Severe: Many symptoms in excess of those required to make the diagnosis, or several symptoms that are particularly severe, are present, or the symptoms result in marked impairment in social or occupational functioning.
what is inattention according to DSM-V
Inattention according to DSM-V= things such as ‘often does not listen when spoken to directly’ ‘often has difficulty in organising tasks and activities’
what is hyperactivity according to DSM-V
Hyperactivity according the DSM-V= things such as ‘often leaves seat in situations when remaining in seat is expected’ ‘often talks excessively’
who found the following: Found that adolescents with ADHD had a higher percentage of behaviours such as getting distracted easily, not following instructions, fidgets than those without ADHD.
Barkley et al., 1990
what are cognitive deficits of ADHD
Impairments in all aspects of executive function (Martinussen et al., 2005; Willcutt et al., 2005)
Executive functions are a set of process involved in the strategic and deliberate allocation of attention and response i.e., this allows us to develop goals and plan.
Executive process are ( Diamond, 2001):
• Inhibition
• Working memory
• Cognitive flexibility
general effects of ADHD
cognitive deficits
longitudinal effects–> academic and schooling
academic impairment and ADHD study
Kent et al., 2010- studies male high school students with ADHD- dolescents with ADHD experienced significant academic impairment in high school relative to comparison adolescents, including lower overall and main academic subject grade point averages (GPA), lower levels of class placement (e.g. remedial vs. honors), and higher rates of course failure
school findings in ADHD (not intellectual)
Loe and Feldman 2007- ADHD is also associated with increased use of school-based services, increased rates of detention and expulsion, and ultimately with relatively low rates of high school graduation and postsecondary education
what are risk factors of ADHD
genetic
neuroatomical:
- frontal cortex
- basal ganglia
- cerebellum
overall size of brain in ADHD
Consistent evidence that the brains of children with ADHD are on average smaller than the brains of healthy comparison children throughout childhood and adolescence (Castellanos et al., 2002; Durston et al., 2002; 2004)
Total brain size in ADHD subjects is approximately 5% smaller than in age and gender matched controls CASTELLANOS et al., 1996
what does the cortex play a key role in?
memory, attention thought and language gradually increases in thickness before reaching a peak during teenage years
what have fMRI scans of the corte revealed
Shaw et al., 2007- Cortex- in normal development the cortex- gradually increases in thickness before reaching a peak during teenage years. fMRI scans have shown than in children with ADHD the cortex generally develops more slowly particularly in frontal and temporal lobe regions (important for memory and controlling behaviour).
PFC size in ADHD
More specifically, the prefrontal cortex (PFC) has been shown to be significantly smaller in ADHD children than controls (Castellanos et al., 1996; Durston et al., 2004; Mostofsky et al., 2002) and in their unaffected siblings (Durston et al., 2004).
but effect in siblings shows cant be full cause
differences in symmetry of prefrontal regions in ADHD
In normal participants there is normally right greater than left asymmetry of the prefrontal cortex. This asymmetry is reduced in ADHD children due to a significant decrease in right prefrontal regions (Castellanos et al., 1996; Reiss et al., 1996;).
basal ganglia and ADHD
Caudate nucleus and putamen serve as the entry point to the basal ganglia and abnormalities of both structures have been shown in ADHD (Pontius 1973; Hill et al., 2003).
caudate volume and ADHD
otal caudate volume was analysed in a mixed longitudinal design- decreased volumes were detected in the ADHD group but only in ages under 16 (castellanos et al., 2002). Around 16 caudate volume seems to normalize. This may provide an explanation to the diminishment of motoric symptoms in ADHD with increasing age.
ADHD and brain injury
ADHD is the most common psychiatric disorder to develop after brain injury (Max et al., 1997) or stroke (Max et al., 2002) in childhood and its occurrence is correlated with severity of injury (Max et al., 1998). Lesions of the right putamen and posterior ventral putamen have been associated with higher incidence of ADHD (max et al., 2002). Another study followed 99 children from 4-19 yrs who suffered closed head injury over the course of a year. During this time odds of developing secondary development ADHD were 3.6x higher in those with basal ganglia injury (Gerring et al., 2000).
what is the role of the basal ganglia
Role of basal ganglia primary function is likely to control and regulate activities of the motor and premotor cortical areas so that voluntary movements can be performed smoothly.(Stocco et al., 2010; Doya, 2000). Limbic sector of the basal ganglia includes various components (caudate nucleus, putamen, nucleus accumbens). Considerable evidence that this limbic part plays a central role in reward learning Schultz 2016.
what is the cerebellum associated with
Associated with coordination of motor movements but also known to be involved with non-motor functions e.g. timing (Allen et al., 1997; Tracy et al., 2000).
