American Board of Psychiatry and Neurology (ABPN) Practice Exam 2025 - Free ABPN Practice Questions and Study Guide

The correct association with chronic pathological gambling is low plasma MHPG concentrations. MHPG, or 3-methoxy-4-hydroxyphenylglycol, is the major metabolite of norepinephrine. Research has indicated that individuals with chronic pathological gambling often exhibit dysregulation in the norepinephrine system, which can be reflected in decreased levels of MHPG. Low MHPG concentrations may suggest an underlying imbalance in norepinephrine activity, which has been linked to impulsivity and compulsive behaviors, both of which are characteristic of pathological gambling.

In contrast, the other options do not have the same established connection with chronic pathological gambling. Increased serotonin activity has been thought to play a role in mood regulation but does not have a direct association with gambling pathology. Decreased glutamate activity does not directly correlate with the neurobiological findings in pathological gambling. Increased norepinephrine levels might be expected in some conditions, but the specific marker of MHPG provides a more accurate reflection of the relationship between norepinephrine and gambling behaviors. Thus, the link between low plasma MHPG concentrations and pathological gambling aligns with the neurological and psychological complexities of the disorder.