These variables measure a respondent's self-assessment of life satisfaction with family life, job, education, etc. Subjective assessments contrast with more "objective" measures such as quality of life metrics, social status, or physical health.
Several files in theARDA's Data Archive have examples of this Measure.
"The psychologically healthy person is one who maintains close contact with reality" (Taylor and Brown 1988:193).
"The perception of reality is called mentally healthy when what the individual sees corresponds to what is actually there" (Jahoda 1958:6).
Definitions of mental health, as well the best way to measure the concept, remain generally debatable.