Behavioral, Neurocognitive, and Treatment overlap between ...
Behavioral, Neurocognitive, and
Treatment overlap between ADHD and
Skirrow, McLoughlin, Kuntsi, Ashwerson, Expert Review.
MS3, UIC COM
ADHD DSM IV Criteria
Attention deficit hyperactivity disorder (ADHD) is a developmentally inappropriate
level of attention, impulsivity, and hyperactivity
Three subtypes: predominantly inattentive type, predominantly hyperactive-
impulsive type, and combined type
DSM-IV Criteria: At least 6 symptoms involving inattentiveness, hyperactivity, or
both that have persisted for at least 6 months:
Inattentiveness: problems listening, concentrating, paying attention to details, or
organizing tasks easily; easily distracted, often forgetful
Hyperactivity-impulsivity: blurting out, interrupting, fidgeting, leaving seat,
talking excessively etc.
Onset before age 7
Behavior inconsistent with age and development
ADHD: Chronic and Life-long
• Impulsivity, inattention, and hyperactivity present as chronic and trait like,
as opposed to symptomatic increases and declines seen in other
• 10-50% have problems adult life with: emotional lability, problems
controlling moods and temper, disorganization and distractibility, and
problems in sustaining effort and completing tasks
Consistently noted alongside these symptoms is mood instability in the
form of irritability, volatility, swift changes in mood, hot temper, and
low frustration tolerance.**
Chronic problems and unstable mood have been noted to present up to 90%
Mood symptoms are likely to impact social behavior and relationships of
adults with ADHD
Unstable and dysregulated mood is predictive of poor social outcome and
peer rejection in children.
Mood Instability and ADHD
DSM IV considers mood instability as an “associated feature of the disorder”.
Without the formal recognition of mood symptoms in ADHD, differentiating ADHD
from other affective disorders difficult, and has lead to misdiagnosis and
incorrect treatment in adults.
Stated rational for excluding mood instability from diagnostic criteria for ADHD is:
lack of reliability and specificity of mood stability. Mood symptoms (i.e.
irritability and dysthymia) are seen in other psych d/o.
Review of recent studies suggest that that there is considerable overlap in
behavioral, neurocognitive, and treatment of ADHD and mood instability.
This review article suggests: Mood instability and symptoms of ADHD may be
intertwined and mood instability should be considered a CORE and DIAGNOSTIC
feature of ADHD syndrome
Mood Instability and Self-regulation of Emotion
Emotional self-regulation: when individual initiates new or alters ongoing emotional
responses via regulatory processes to attain social or personal goals
Zeman et al. described self-regulation of emotion as involving management and
organization of diverse components:
--internal component (neurophysiologic, cognitive, subjective evaluations)
--behavioral component (facial expression and behavioral actions)
--external/social component (cultural values and social contextual significance)
Difficulties in reacting appropriately to a social situation may stem from different
underlying problems: impaired understanding of emotional information (ex facial
expressions), a lack of empathetic experience for others, inattentiveness to social
cues, or a lack of understanding of social norms. These are functions that are
impaired in ADHD.
Studies suggest that individuals with ADHD have problems with emotional self-
regulation even when individuals with ADHD understand are aware of the need to
regulate emotional behavior, they have difficulty successfully regulating either
Mood Instability and Executive Function
Executive dysfunction: deficits in "higher-order" cognitive processes, such as
planning, sequencing, reasoning, holding attention to a task, working memory,
inhibition of inappropriate and selection of appropriate behaviors. These supervisory
processes control, regulate and manage the "lower-level" cognitive operations, such
as language, perception, explicit memory, learning and action.
Barkley, proposed model*: Impairments in cognitive and executive function could
be explained by core inhibition deficit in ADHD. This inhibition theory tries to
explain classic behavior of ADHD: impulsivity, hyperactivity, and co-occurrence of
mood instability. Theory states inhibitory processes are essential to for self-
Overlap with Mood instability--pts with ADHD are unable to inhibit emotional
reactions and so unable to delay responding to factor in social context for
appropriate response, resulting in emotionally reactive, irritable and hostile
Several studies conclude that mood instability is associated with deficits in
performance of executive function tasks known to be associated with ADHD. Kids
and adults with ADHD due worse on tests of executive functions when compared to
Mood Instability and State Regulation
State regulation and cognitive energy models of ADHD highlight evidence that
individuals with ADHD tend to make errors and are slow and more variable in
responding in a range of cognitive tasks.
Electroencephalography studies suggest that individuals with ADHD show cortical
under arousal, as measured by increased frontal and central theta activity,
continuing from childhood in to adulthood. Intra-individual variability in ADHD may
be due cerebellar dysfunction, reflecting temporal processing deficits, motor
control deficits, or inability to appropriately model very low frequency fluctuations
in neuronal activity or dysfunction of executive attention.
Hypothesized: Executive function deficits and variable response seen in ADHD may
be secondary to altered arousal or activation states (heart rate, skin conductance,
pupil dilation etc).
Relationship between mood instability and executive function caused by deficits in
inhibitory or attention processing which in turn is due to problems in state
State regulation deficits may directly influence mood instability by giving rise to
greater variability and performance measures.
Overlap of Brain Structures between
Mood Instability and ADHD
Neuroimaging and brain injury research has shown overlapping brain structures
and networks in the regulation of behavior and the regulation of emotion.
Common brain regions have been associated with inattention, impulsive,
hyperactive and emotionally dysregulated behavior.
Frontal lobes –linked with attentional and inhibitory functions
Subcortical limbic and basal ganglia systems—linked with motivational process and
Reciprocal neural connections exist between prefrontal cortical regions and
subcortical regions, which may allow for interactions between cognitive and
Functional and structural MRI studies demonstrated altered functional activation
and reduced volumes in prefrontal, basal ganglia, and the cerebellum in ADHD pts
versus psychiatrically healthy controls.*
Mood Instability and ADHD:
Response to Treatment
Several studies have found mood instability responds to both stimulant and non-
stimulant treatments of ADHD in the same time frame as core ADHD symptoms in
adults with ADHD.
Methylphenidate, a NE & DA reuptake inhibitor, is stimulant medication most
commonly used to treat ADH.
Double-blind placebo studies of methylphenidate have found concurrent
improvement in both ADHD and mood symptoms. Adult ADHD pts reported feeling
happier, less anxious, less depressed, less angry, and with cooler temper as part of
Atomoxetine, a NE reuptake inhibitor and most common non-stimulant treatment
for ADHD. Double-blind placebo studies of atomoxetine demonstrated mood
stability and ADHD symptoms improved with treatment.
Much of study treatment was carried out in adults but needs replication in
Top Down and Bottom Up Theories of ADHD
Theories of ADHD grouped into pure “top-down” executive function control and
pure “bottom-up” affective/reactive processes related to inattention and
Top-down processes are related to more effortful forms of control. Behaviorally,
this kind of control refers to behavior that is goal-directed, resource-demanding,
and planful , or when there is a need to overcome immediate stimuli in order to
maintain progress toward a goal held in working memory. Neurally, top-down
processes are thought to rely primarily on prefrontal circuitry, particularly in its role
of suppressing task irrelevant activation elsewhere in the brain.
Bottom-up processes are thought to be related to behavior that does not demand
conscious mental resources and which are more heavily influenced by immediate
incentive or affective response. This kind of processing is believed to rely on
stimulus-driven activation either in parietal cortex (in the case of attentional
capture) or subcortically (e.g., in striatum or limbic regions), particularly in its role
of interrupting motor or cognitive processing being implemented in frontal cortex,
redirecting attention to an immediate salient event.
Bidirectional Multiple Pathway Model
Nigg and others: Not just one single process theory can account for the range of
cognitive and neuropsychological impairments associated with ADHD construct.
Propose combination of Top-down executive control (e.g. suppressing competing
responses) and bottom-up motivational or state regulation processes (e.g.
arousal, activation or delay-reward gradient) may better account for the range of
cognitive and neuropsychological problems seen in ADHD.
This approach can help account for heterogeneity in ADHD, as well as association of
ADHD with mood instability, which preferentially be associated with deficit in one
particular pathway but not within another.
There are number of important limitations to research of ADHD and mood instability,
most importantly is contribution of comorbid disorders. Mood instability in ADHD pts
may be due to unaccounted for comorbid mood disorder, but it appears highly
unlikely, since mood instability is found to improve with treatment for ADHD.
Research suggest, mood instability can be attributed to ADHD syndrome.
ADHD persists to adulthood in many cases
Pts with ADHD often show mood instability characterized by mood changeability,
irritability, volatility, hot temper, low frustration tolerance.
ADHD is associated with impairment across a wide range of executive and non-
executive tasks, which have been associated with mood instability.
Brain regions involved in emotional regulation and mood stabilization are found to
show structural and functional changes in ADHD.
Treatment for ADHD with stimulant medications results in improvement in mood
instability alongside ADHD symptomalogy.
Need more research to clarify the relationship between mood instability to ADHD
and to clarify the distinction from overlapping disorders, such as borderline
personality d/o and Bipolar d/o.
Pts presenting with chronic mood instability associated with core features of ADHD
(child or adolescent onset, trait-like course, inattention, hyperactivity, and
impulsivity) should be screened for ADHD.
Faraone, Biederman, Mick. The Age dependent decline of ADHD: meta-analysis of follow up
studies. Psychol. Med. 2006.
Johnson, Wiersema, Kuntsi, 2009.; Casey 2005; Holroyd and Coles 2002; Nigg and Casey 2005
Barkley, Murphy, Fischer. ADHD in Adults. 2007.
Reimhert, Marchant, Stronge et al. Emotional dysregulation in adult ADHD and response to
amoxetine. Biol. Psych. 2005.
Asherson P. Clinical assessment and treatment of ADHD in adults. Expert Rev. Neurother.2005.
Mcloguhlin, Kuntsi, Brandeis. Electrophysiological parameters ADHD. 2005.
Castellanos, Tannock. Neuroscience of ADHD. 2002.
Nigg, Casey, An Integrative theory of ADHD based on cognitive an affective neurosciences. Dev.
Sonuga-Barke EJ. The Dual Pathway model of ADHD. Biobehav. Rev. 2003.
A particular slide catching your eye?
Clipping is a handy way to collect important slides you want to go back to later.