Now in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, Assessing Relationships Among Impulsive Sensation Seeking & Reward
Scientists seeking to improve understanding of bipolar disorder have focused on impulsive sensation seeking—a complex trait characterized by impulsivity (acting without advance thought) and sensation seeking (seeking new or extreme experiences). Some research has indicated that high impulsivity may be an early sign or symptom of bipolar disorder.
Impulsive sensation seeking is associated with the greater valuation and motivational salience of potential reward. Some researchers are particularly interested in reward expectancy, a state in which those with high impulsive sensation-seeking behaviors are more likely to make impulsive decisions, thought to increase the chances of receiving the reward. In prior studies, scientists have implicated the left ventrolateral prefrontal cortex and the bilateral ventral striatum in young adults with or at risk for bipolar disorder when performing a reward processing task. This research has helped scientists identify the left ventrolateral prefrontal cortex and the bilateral ventral striatum as potentially important biomarkers for bipolar disorder.
In a study published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, investigators including Kale Edmiston, PhD, the study’s first author, Jay Fournier, PhD, Henry Chase, PhD, Michele Bertocci, PhD, Erika Forbes, PhD, and Mary Phillips, MD, MD (Cantab) from Pitt Psychiatry sought to replicate prior findings of an association between impulsive sensation seeking and reward expectancy-related activity. They expanded the scope of the previous experiment to examine the relationship between brain activity and each impulsive sensation-seeking component separately.
“There is a great need for replication studies in psychiatric neuroimaging. Replications are quite challenging, but they increase our confidence in the validity of our findings,” said Dr. Edmiston.
The investigators recruited 61 adults, ages 18–25, who were seeking psychological treatment, as well as 66 participants with no history of psychiatric illness. All participants were assessed for depression and symptoms of affective disturbance, as well as measures of impulsive sensation seeking. Participants then undertook a reward task while undergoing functional magnetic resonance imaging.
The investigators replicated the positive association between negative urgency (an impulsive sensation seeking component characterized by the tendency to act impulsively during negative emotional contexts) and reward expectancy-related left ventrolateral prefrontal cortical activity. In addition, the findings showed that negative urgency statistically accounted for (i.e., mediated) the positive relationship between reward expectancy-related left ventrolateral prefrontal cortex activity and hypomanic or manic symptoms.
“We have been able to demonstrate in two independent samples that elevated activity in the left ventrolateral prefrontal cortex during reward expectancy predisposes to a specific facet of impulsivity, negative urgency,” remarked Dr. Phillips, the study’s senior author. “Furthermore, we now show that negative urgency is the critical mediating link between left ventrolateral prefrontal cortical activity and predisposition to hypomania or mania. Along with our other studies in this field of research, our findings indicate that the left ventrolateral prefrontal cortex might be a suitable neural target for new interventions that aim to delay or even halt the progression to mania in individuals who might be at future risk of bipolar disorder or related disorders.”
Assessing Relationships Among Impulsive Sensation Seeking, Reward Circuitry Activity, and Risk for Psychopathology: A Functional Magnetic Resonance Imaging Replication and Extension Study
Edmiston EK, Fournier JC, Chase HW, Bertocci MA, Greenberg T, Aslam HA, Lockovich J, Graur S, Bebko G, Forbes EE, Stiffler R, Phillips ML
Biological Psychiatry: Cognitive Neuroscience and Neuroimaging Published: November 07, 2019 DOI: https://doi.org/10.1016/j.bpsc.2019.10.012