Celine is most likely suffering from "clinical depression".
Depression ranges in seriousness from mild, brief scenes of pity to serious, relentless despondency. Clinical depression is the more-extreme type of sorrow, otherwise called significant misery or real depressive issue. It isn't the same as sorrow caused by a misfortune, for example, the demise of a friend or family member, or a restorative condition, for example, a thyroid issue.