[T]he emerging 'transdiagnostic approach' to mental health ... defines
mental health along a continuum; according to this view, we all share
the psychological processes, such as irrational beliefs, anxieties and
low moods, that underlie so-called 'disorders', but we exhibit them to
varying degrees. This helps to account for the apparent overlap
between traditional disorders, and makes more sense of the broad
spectrum of mental health experiences -- from more common, everyday
stresses and anxieties understood by almost all people, to anxiety,
mood, psychotic or eating difficulties that interfere with someone's
ability to function in their daily life.