What are the motifs in Seeds of Yesterday by V.C. Andrews?

Co-Dependency means that a person must have a problem, situation or concern in their lives at all times. It means someone needs to be needed.

The Sheffield/Foxworth family has Co-Dependency issues at various levels. Because of the horrible past they shared as children, Catherine needs to be needed by her brother Chris. Isolated in the attic for a time, they only had each other. Chris, likewise, needs Catherine.