Marianne Frankenhauser and her colleagues in Sweden have confirmed the involvement of two neuroendocrine systems in the stress response — the sympathoadrenal medullary system (which secretes the catecholamines, adrenalin and noradrenalin), and the pituitary-adrenal cortical system (which secretes corticosteroids such as cortisol).
Building on the work of Henry and Stephens (41), Frankenhauser has shown that under demanding conditions where the organism can exert control, i.e., in the face of controllable and predictable stressors (analogous to “active” work in the Karasek model), adrenalin levels increase, but cortisol decreases. Effort without distress is experienced. However, in demanding low control situations (analogous to Karasek’s “high strain” jobs), where demands are perceived as excessive or threatening, both adrenalin and cortisol are elevated and effort with distress is experienced (26, 27, 57). In Frankenhauser’s model, low demand-low control situations (analogous to Karasek’s “passive” jobs or Seligman’s concept of “learned helplessness” (1)) create feelings of depression and helplessness and elevated cortisol, although only mild elevations in catecholamines (26).
Personal control may exert a positive effect by reducing the duration of the stress response (26). Repetitive and machine-paced jobs, as well as excessive overtime, tend to prolong “unwinding”, the return of neuroendocrine levels to baseline (26, 27).
This model has not so far been related to sustained hypertension, but is relevant because adrenalin and cortisol are both potential pressor hormones (Schwartz, Pickering and Landsbergis, 1996). Elevated levels of both catecholamines and cortisol appear to have severe consequences for myocardial pathology (104, p. 90).
Schwartz JE, Pickering TG, Landsbergis PA. Work-related stress and blood pressure: Current theoretical models and considerations from a behavioral medicine perspective. Journal of Occupational Health Psychology 1996 (in press).