I coin the word wholing as a noun or participle meaning to become whole, in order to distinguish it from the more familiar participle, healing. For understanding salvation, wholing, I think, is a better metaphor than healing, because the results of sin are more like a split than a sickness. Also sickness or illness (a metaphor drawn from body treatments), although far more familiar than splitness (disallowed even by my spell-checker), also implies the possibility of correction by a doctor and/or medicine--both outside agents, whereas splitness is only resolved by re-uniting from within. Outside agents may heal one who is diseased or physically hurt, but no outside force like a doctor or drugs can whole one who is divided within. 

The benefits of confession, confiding, therapy, self-analysis, journaling, etc., are not in forces brought from outside agents (e.g., a priest bringing forgiveness, a friend giving advice, a therapist acting like a doctor, an analysis bringing lost information, or the act of writing "being therapeutic"). Rather they lie in the wholing which may occur when we dare confront and embrace split-off parts of self while in either of these processes. 

One danger in such names as "mental illness" is that they invite a mind set of needed healing. If we are sick, either physically or mentally (as though the two are divisible), then all human experience with doctors, medicines, and treatments is reasonably evoked. All illnesses are primarily "treated" by external forces. Once this same mode of thinking is brought to the process which is more literally like wholing than healing, we cannot but be distracted by hopes of finding similarly effective outside healing agents.

(Of course, the notion of healing may also be reasonably applied to "curing" a split; but I doubt that one can easily make this fine mental distinction while hurting (another physical metaphor) from internal divisions. All too easily a mind in distress imagines the possibility of a "mental" or "spiritual" doctor who can bring healing to the mind just as a physician does to the body. Unfortunately, the metaphor breaks down at this point.)