Justin Jones, Ph.D. | Clinical & Forensic Psychologist | April 2026

In high‑conflict custody disputes, courts are often faced with allegations of mental disorder, emotional instability, or risk to the child. But a categorical diagnosis – for example, “Borderline Personality Disorder” – is insufficient. What truly matters for the judicial decision is the parent’s personality structure: how they organize identity, regulate affects, use defenses, and relate to others.

In this article, I explain why forensic psychological evaluation in custody must go beyond symptoms and how understanding personality organization can change the outcome of a case.

Limitations of categorical diagnosis in custody

The DSM‑5‑TR offers useful criteria, but many parents in litigation do not fit neatly into a specific disorder – yet they may still show significant impairment in parental functioning. A parent with identity diffusion may oscillate between being overprotective and neglectful, without meeting full criteria for a personality disorder. Another may use primitive defenses (splitting, projection) only under litigation stress, but not in other areas of life.

Dimensional diagnosis, using models such as the AMPD (DSM‑5‑TR) or the PDM‑2, captures these degrees of impairment and allows a more precise formulation: the level of personality functioning (from neurotic to psychotic), the predominant pathological traits, and the capacity for mentalization under stress.

What to assess in a custody evaluation?

• Identity organization: Does the parent have a coherent and stable sense of self? Or do they show contradictions, emptiness, and excessive reliance on external validation?
• Predominant defenses: Do they use mature defenses (humor, sublimation) or primitive ones (splitting, denial, projective identification) – especially in conflict with the other parent?
• Mentalization capacity: Can they understand the mental states of the child and the ex‑partner, or do they misinterpret behavior in distorted ways?
• Emotional regulation: Is there a tendency toward outbursts, rumination, or avoidance that impacts the child’s routine?
• Risk of parental alienation or conflict escalation: Does the personality structure favor triangulation or demonization of the other parent?

How structural evaluation assists the court

A forensic report that merely lists symptoms leaves room for superficial counter‑reports. An evaluation based on personality structure provides:

• Clear opinion on parenting capacity: not just whether there is a diagnosis, but whether personality organization compromises the child’s emotional safety.
• Specific recommendations: for example, supervised visitation, specialized therapy (TFP, DBT), or a parenting program.
• Risk prediction: the likelihood of conflict escalation or alienation, based on the parent’s defensive patterns.
• Tools to rebut weak opposing reports: many experts still rely on unstructured interviews; a multi‑method approach (interviews, testing, record review) is more defensible.

Practical example (conceptual, anonymized)

A parent had a diagnosis of BPD from a treating psychiatrist. In the forensic evaluation, we observed identity diffusion, use of splitting (idealizing the new partner and devaluing the ex‑spouse), and poor mentalization under stress. However, the child was already in a stable environment with the other parent. The report recommended that custody remain with the more structured parent, but with expanded visitation provided the parent with BPD started TFP. The court agreed, and after one year the parent improved coparenting capacity – avoiding a complete rupture of the bond.

Conclusion

Attorneys practicing family law need experts who understand the difference between a labeling diagnosis and a structural formulation of personality. A well‑founded evaluation not only strengthens the case but also protects the child’s best interest.

I am available for pre‑litigation consultation, full evaluation, or review of opposing reports. CV available upon request.