Antagonists. There is always good and bad, and the same is true with companion planting. Certain plants should not be used as companion plants for potatoes. These include turnips, pumpkins, cucumbers, rutabagas, sunflowers, tomatoes, squash and raspberry. These antagonistic plants can hinder potato growth.
Mental breakdown (also known as a nervous breakdown) is a general term for an acute, time-limited mental disorder that manifests primarily as severe stress-induced depression, anxiety, or dissociation in a previously functional individual, to the extent that they are no longer able to function on a day-to-day basis until the disorder is resolved.
Sister complex is part of the lexicon of current pop culture, and is not a diagnosable mental illness. A complex, in general, refers to an unconscious constellation of psychological and emotional factors that influence a person's feelings and behavior. In psychoanalytic theory, a complex was a feature of neurosis, a mild mental disorder that caused anxiety and distress, but not psychotic symptoms.