Adult ADHD
Visual Abstract
Motivation deficit in ADHD is associated with dysfunction of the dopamine reward pathway
Dopamine and Motivation in ADHD
N D Volkow , G-J Wang, J H Newcorn, S H Kollins, T L Wigal, F Telang, J S Fowler, R Z Goldstein, N Klein, J Logan, C Wong, J M Swanson
Summarized by:
May 24, 2023
study source
Mol Psychiatry
Nov 2011
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What they studied
The study wanted to see if those with ADHD have differences in motivation and whether this is linked to differences in the brain.
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What they found
By analyzing brain imaging, researchers found differences within the brain’s reward system between those with ADHD and those without ADHD. These differences correlated with motivation.
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What this means
These results suggest that motivation is a fundamental part of ADHD, with a biological basis. It also highlights the key role of the reward system of the brain and dopamine in ADHD.
Motivation deficit in ADHD is associated with dysfunction of the dopamine reward pathway
Objectives
ADHD is typically associated with symptoms involving attention and impulsiveness.
But it can also affect other parts of our personality and cognition, including our motivation.
This study wanted to use brain imaging to see whether dopamine, involved with our brain's reward system, was associated with difficulties with motivation in ADHD.
Study Quote
Attention-deficit hyperactivity disorder (ADHD) is typically characterized as a disorder of inattention and hyperactivity/impulsivity but there is increasing evidence of deficits in motivation. Using positron emission tomography (PET), we showed decreased function in the brain dopamine r...
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Methods
This study analyzed brain imaging from 45 adults with ADHD and compared them to imaging from 41 adults without ADHD.
Their imaging technique allowed them to see the levels and locations of dopamine receptors.
Study Quote
To evaluate this hypothesis, we performed secondary analyses to assess the correlation between the PET measures of dopamine D2/D3 receptor and dopamine transporter availability (obtained with [(11)C]raclopride and [(11)C]cocaine, respectively) in the dopamine reward pathway (midbrain and...
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Results
The results from personality testing on the participants show that, generally, those with ADHD had less motivation to achieve.
Their brains overall also had less dopamine in the brain’s reward system.
Among those with ADHD, the data showed that those with more dopamine receptors, at levels closer to normal, also functioned better compared to their peers.
Study Quote
The Achievement scale was lower in ADHD participants than in controls (11±5 vs 14±3, P<0.001) and was significantly correlated with D2/D3 receptors (accumbens: r=0.39, P<0.008; midbrain: r=0.41, P<0.005) and transporters (accumbens: r=0.35, P<0.02) in ADHD participants, but not in contro...
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Conclusions
Consistent with previous studies, the researchers found that those with ADHD had more difficulty with motivation.
This study found a potential biological basis for this effect. Those with ADHD and more difficulty with motivation had significant brain differences, particularly in how they processed motivation and rewards.
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These are key brain regions for reward, and the observed decreased availability of D2/D3 receptors and DAT could explain the decreased motivation in these patients.
These results suggest that differences in motivation are a fundamental part of ADHD, correlated with significant biological differences in the brain.
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The observation of a deficit in the DA reward pathway is further evidence that deficits in motivation may be contributing to impairment in ADHD adults
Previous studies have found that those with ADHD often have difficulty with education and employment as young adults. This research provides a potential basis for these challenges:
Study Quote
These findings provide evidence that disruption of the dopamine reward pathway is associated with motivation deficits in ADHD adults, which may contribute to attention deficits and supports the use of therapeutic interventions to enhance motivation in ADHD.