RESEARCH INTO THE EFFECTS OF STRESS ON THE IMMUNE SYSTEM
COHEN ET AL 1993

394 participants
completed questionnaire on stressful life events in past year
rated their stress levels and negative emotions
stress index created from 3 scores, ranged from 3-12
participants exposed to one of fie cold viruses
administered through nasal drops
diagnosed after 7 days by a doctor
number of participants who developed colds was recorded
all showed signs of infection
82% developed a cold
direct link between stress and illness
those scoring highly on stress index most likely to develop the cold

+high internal validity due to controlled variables such as age, weight and smoking etc. meaning we can be more certain that the development of the cold was less likely to be due to factors other than stress

-unclear cause and effect relationship and so cannot be sure that immune function is affected by stress levels. e.g. does being stressed lead to illness or does illness lead to stress. a cyclic process?

	Created by jessie_alexander over 9 years ago

RESEARCH BY COHEN ET AL 1993. AQA