Final answer:
The death of a spouse is rated as the most significant event on the Social Readjustment Rating Scale with 100 LCUs, indicating the highest level of stress and required personal readjustment.
Step-by-step explanation:
The most major life event in life change units (LCUs) on the Social Readjustment Rating Scale (SRRS) is the death of a spouse, which is rated at the highest with 100 LCUs. This scale, developed by psychiatrists Thomas Holmes and Richard Rahe in the 1960s, lists 43 life events that necessitate varying degrees of personal adjustment. The events are quantified in terms of LCUs to assess the level of stress they may induce. For instance, divorce is second highest with 73 LCUs, while personal injury or illness, marriage, and job termination are also among the top stressors with 53, 50, and 47 LCUs respectively. Lower stress events include change in residence, change in eating habits, and vacation. The accumulation of a high number of LCUs within a short timeframe has been correlated with an increase in physical illnesses and mental health problems.