Cholinergic-adrenergic balance: Part 2. Relationship between drug sensitivity and personality

Sensitivity to the centrally active cholinomimetic physostigmine varies dramatically among healthy individuals. The elucidation of the reasons for this variability could contribute to the understanding of the pathophysiology of affective disorders where a cholinergic supersensitivity has been demonstrated. Therefore, personality characteristics and habitual stress-coping strategies were related to sensitivity to physostigmine in eight healthy male volunteers. Cardiovascular and behavioral responses tended to be positively correlated with irritability and emotional liability. Passive, "helpless" strategies for coping with stress were positively related to these responses. The metabolic and neuroendocrine responses to physostigmine were generally unrelated to personality. In view of putative beta-adrenergic disturbances in depression, the responses to the peripheral beta 2-adrenergic agonist reproterol were studied. Irritability and emotionality tended to be positively correlated with cardiovascular responses to reproterol as well as with reductions of heart rate by the peripheral cholinomimetic neostigmine.