According to Brain/Mind Bulletin (May 1988) John Barefoot of Duke University has found a negative correlation between suspiciousness and longevity. In a sample of 500 older men and women whose health he monitored for 15 years, Barefoot discovered that:
(a) those who scored high on suspiciousness, cynicism and hostility died sooner than all others;
(b) this high mortality remained constant when compared by age, by sex, by previous health, by diet and even by "bad habits." [Those who smoked and remained generally optimistic lived longer than those who smoked and worried about it.]
(c) those who scored highest on hostility had a death rate more than six times higher than others.
In a related study (Brain/Mind Bulletin August 1988) Shelley Taylor of UCLA and Jonathon Brown of SMU refuted the conventional idea that those who score high on "mental health" generally have a fewer number of illusory beliefs. Among the most common illusions of the mentally healthy:
(a) overly positive views of themselves;
(b) convenient "forgetting" of negative facts about themselves;
(c) illusory beliefs about having more control than they do have;
(d) "unrealistic" optimism about themselves;
(e) "unrealistic" optimism about the future in general;
(f) "abnormal" cheerfulness.
Kinda puts a different spin on what might be viewed as mental health; this might be called Survival Emotional/Mental Health.
"The greatest discovery of my generation is that a human being can alter his life by altering his attitude." - William James; 19th century pioneer of psychology.