The influence of positive and negative mood states on risk taking, verbal fluency, and salivary cortisol

Background: Neuropsychological studies in depressed and manic patients have revealed significant frontal cortex dysfunction. It is hypothesised that performance on frontal lobe tasks may be sensitive to induced fluctuations in mood state in non-clinical samples. Methods: Subjects performed one of two neuropsychological tasks immediately subsequent to a musical mood induction procedure designed to induce either elation or depression. Mood was assessed using self-report measures. Salivary cortisol levels were also measured in an attempt to objectively validate mood induction effects. The tasks used were verbal fluency and Damasio’s Gambling Game. Two groups of subjects were recruited: a group with previous (subclinical) hypomanic experience (n=23) and a control group without previous hypomanic experience (n=23). Results: The positive and negative mood inductions produced robust and contrasting effects on self-reported mood, but had no significant differential effects on salivary cortisol levels and neuropsychological performance. Limitations: The findings are restricted by the absence of a neutral mood control condition. Conclusions: Salivary cortisol recording does not provide a simple and reliable method of validating psychological mood induction. Performance on frontal lobe tests appears to be insensitive to normal mood fluctuations, which supports the argument that the deficits in mood disorder patient groups may instead reflect core disturbances of neurobiological processes.