Deviation from ideal mental health was introduced by Jahoda and has a list of ideal mental health expectations. This list includes having an accurate view of reality, being able to resist stress and a strong sense of identity.
Jahoda was a humanistic psychologists, with self actualisation on the list for ideal mental health. This limits the definition as it is very hard and unrealistic to achieve.
Failure to function adequately is being unable to cope with demands of everyday life.
Cognitive biases are focuses on the negative, like catastrophising ad overgeneralisations.
Disputing in Ellis's REBT is logical, empirical and pragmatic.