It is not divorce that harms children
(although litigation can compound the problem). It is co-parental conflict that can cause children to become angry and depressed, anxious and withdrawn. Co-parental conflict can be associated with children's school failure, escape into substance use, self-destructive behaviors, promiscuity and more.

When co-parental conflict becomes frequent and severe,
help is needed. Couples' or marital therapies can be part of the answer. Individual therapy for each of the adults can be a critical support. Child therapies can be necessary (even if not sufficient) to help the kids keep their heads above the rising tide of anger.

Alternative dispute resolution
(mediation and arbitration) can also be helpful. Go to the New Hampshire Conflict Resolution Association (NHCRA)

When conflicted co-parents are married,
separation and/or divorce can become part of the answer. With all due respect to the sensitive ethics and morals of the matter, divorce can be a healthy  child-centered solution in some situations.

When parents bring their conflict into the courts, a
Guardian ad litem
(GAL) can be assigned. A GAL is a child-centered professional assigned by the court to investigate specific matters relevant to the co-parents conflict (e.g., parenting rights and responsibilities) in order to advise the court. The GAL typically has no decision-making authority and is not a "helper" to the family. In most cases, the GAL's job is done when his or her investigation is delivered in writing to the court.