Drug abusers have impaired cerebral oxygenation and cognition during
exercise
Drug addiction, cognition, incremental exercise, prefrontal cortex
Background: Individuals with Substance Use Disorder (SUD) have lower baseline
metabolic activity of the prefrontal cortex (PFC) associated with impairment of
cognitive functions in decision-making and inhibitory control. Aerobic exercise has
shown to improve PFC function and cognitive performance, however, its effects on
SUD individuals remain unclear. Purpose: To verify the cognitive performance and
oxygenation of the PFC during an incremental exercise in SUD individuals.
Methods: Fourteen individuals under SUD treatment performed a maximum graded
exercise test on a cycle ergometer with continuous measurements of oxygen
consumption, PFC oxygenation, and inhibitory control (Stroop test) every two
minutes of exercise at different intensities. Fifteen non-SUD individuals performed
the same protocol and were used as control group. Results: Exercise increased
oxyhemoglobin (O2Hb) and total hemoglobin (tHb) by 9% and 7%, respectively.
However, when compared to a non-SUD group, this increase was lower at high
intensities (p<0.001), and the inhibitory cognitive control was lower at rest and during
exercise (p<0.007). In addition, PFC hemodynamics during exercise was inversely
correlated with inhibitory cognitive performance (reaction time) (r= -0.62, p=0.001),
and a lower craving perception for the specific abused substance (p=0.0189) was
reported immediately after exercise. Conclusion: Despite SUD individuals having
their PFC cerebral oxygenation increased during exercise, they presented lower
cognition and oxygenation when compared to controls, especially at elevated
intensities. These results may reinforce the role of exercise as an adjuvant treatment
to improve PFC function and cognitive control in individuals with SUD.