Coercive Control and Psychiatric Injury: How Expert Evidence Has Changed Since the Domestic Abuse Act 2021

In abuse injury medico-legal practice, the recognition of coercive control as a distinct form of domestic abuse has transformed the landscape of psychiatric and psychological evidence. The Domestic Abuse Act 2021 (DAA 2021) codified coercive control as a criminal offence under Section 76 of the Serious Crime Act 2015, reinforcing its legal status and prompting a shift in how expert witnesses assess psychiatric injury in survivors. For solicitors, barristers, and instructing parties, understanding these changes is critical—particularly in civil claims, Criminal Injuries Compensation Authority (CICA) matters, and group litigation where psychiatric harm is alleged.

Clinical Context: Coercive Control and Psychiatric Injury

Coercive control is characterised by a pattern of behaviour designed to dominate, isolate, and intimidate a victim, often without overt physical violence. In the experience of medico-legal psychiatrists and psychologists working in abuse claims, the psychiatric sequelae of coercive control frequently include:

• Complex Post-Traumatic Stress Disorder (CPTSD) under ICD-11, which encompasses PTSD symptoms alongside disturbances in self-organisation, such as emotional dysregulation, negative self-concept, and interpersonal difficulties.
• Depression and anxiety disorders, often with chronic, treatment-resistant presentations.
• Dissociative symptoms, including depersonalisation and derealisation, particularly in cases of prolonged exposure.
• Somatic symptom disorders, where psychological distress manifests as physical symptoms.
• Reactive attachment disorder or attachment trauma, particularly in cases involving child survivors or where the claimant was isolated from support networks.

It is widely recognised in trauma-informed casework that coercive control can result in sustained psychological harm, even in the absence of physical violence. The Walker Cycle of Violence framework, though originally developed for physical abuse, is often adapted to explain the cyclical nature of coercive control, where periods of tension-building and reconciliation create a pervasive sense of unpredictability and fear.

Assessment Frameworks for Coercive Control

Expert witnesses in abuse injury claims increasingly rely on validated assessment tools to evaluate the impact of coercive control. These may include:

• International Trauma Questionnaire (ITQ) for CPTSD, which aligns with ICD-11 criteria.
• PCL-5 and CAPS-5 for PTSD symptoms.
• Trauma Symptom Inventory-2 (TSI-2) to assess a broad range of trauma-related symptoms.
• Childhood Trauma Questionnaire (CTQ) where developmental trauma is relevant.

In cases where symptom validity is in question—such as in high-stakes litigation or where malingering is alleged—tools like the Structured Inventory of Malingered Symptomatology (SIMS) or Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) may be employed. However, expert opinion must always emphasise that trauma survivors may exhibit atypical or fluctuating symptom presentations, and rigid application of psychometric cut-offs can lead to misdiagnosis.

Legal Relevance: The Domestic Abuse Act 2021 and Expert Evidence

The DAA 2021 has had a profound impact on how coercive control is framed in legal proceedings. Key implications for expert evidence include:

1. Recognition of Non-Physical Harm

Prior to the DAA 2021, psychiatric injury claims often struggled to establish causation where physical violence was absent. The Act’s explicit recognition of coercive control as a form of abuse has strengthened the evidential basis for claims where psychological harm is the primary injury. In the context of CICA claims, this has also influenced the application of mental injury tariffs, particularly under Band 3 (moderate) or Band 4 (severe) where CPTSD or chronic depression is diagnosed.

2. Limitation and Historic Abuse

For historic coercive control claims, the Limitation Act 1980 remains a significant hurdle. However, the DAA 2021 has provided fresh impetus for courts to apply Section 33 discretion, particularly where the claimant’s psychological state at the time of the abuse (e.g., fear, isolation, or learned helplessness) contributed to delayed disclosure. Expert evidence addressing betrayal trauma theory—which explains why victims may suppress memories of abuse by trusted perpetrators—can be pivotal in such cases.

3. Vicarious Liability and Institutional Failures

In cases involving institutional settings (e.g., workplace harassment, educational environments, or care facilities), the DAA 2021 has reinforced the duty of care owed to individuals at risk of coercive control. Expert witnesses may be instructed to assess whether systemic failures contributed to the claimant’s harm, drawing on authorities such as Various Claimants v Barclays Bank plc [2020] UKSC 12 (vicarious liability) or Armes v Nottinghamshire County Council [2017] UKSC 60 (local authority duties).

Common Pitfalls and Disputes in Coercive Control Evidence

Despite advances in clinical and legal understanding, several challenges persist in coercive control psychiatric evidence:

1. Diagnostic Overreach

Not all survivors of coercive control develop CPTSD or other psychiatric disorders. Expert witnesses must avoid conflating normative distress with diagnosable conditions. A trauma-informed assessment should distinguish between:

• Adjustment disorders (where symptoms resolve with removal from the abusive environment).
• PTSD or CPTSD (where symptoms persist and meet full diagnostic criteria).
• Pre-existing or comorbid conditions (e.g., personality disorders, which may be exacerbated by abuse but not caused by it).

2. Causation Errors

Defendant parties may argue that the claimant’s psychiatric injury predated the alleged abuse or arose from unrelated stressors (e.g., financial difficulties, bereavement). Expert witnesses must conduct a thorough but-for analysis, considering:

• The temporal relationship between the abuse and symptom onset.
• The claimant’s pre-abuse mental health history (where records exist).
• The specific mechanisms by which coercive control can cause psychiatric harm (e.g., chronic stress, social isolation, gaslighting).

3. Failure to Recognise Complex Trauma Presentations

Coercive control often involves chronic interpersonal trauma, which can lead to presentations that differ from single-event PTSD. Survivors may exhibit:

• Emotional dysregulation (e.g., explosive anger or emotional numbness).
• Negative self-concept (e.g., pervasive shame or self-blame).
• Interpersonal difficulties (e.g., distrust of others or revictimisation).

Expert witnesses unfamiliar with complex trauma may misattribute these symptoms to personality disorders or other conditions, undermining the claimant’s case.

4. Malingering Concerns

In high-value claims or where credibility is contested, defendant parties may allege malingering. While symptom validity testing can provide objective data, expert witnesses must emphasise that:

• Trauma survivors may underreport symptoms due to shame or avoidance.
• Psychometric tools are not infallible and must be interpreted in clinical context.
• Coercive control can create a learned helplessness response, where survivors minimise their own suffering.

The Role of the Expert Witness in Coercive Control Claims

Instructing a trauma-informed expert witness is critical in coercive control cases. The types of reports that may be commissioned include:

• Condition and Prognosis reports: Assessing the claimant’s current psychiatric state, treatment needs, and long-term outlook.
• Liability and Causation reports: Addressing whether the alleged abuse caused or materially contributed to the psychiatric injury, with reference to clinical frameworks and legal tests.
• Quantum and Care Needs reports: Evaluating the claimant’s functional impairments, care requirements, and future losses.
• Psychiatric or Psychological assessments: Often incorporating psychometric testing to support diagnostic conclusions.
• Single Joint Expert (SJE) reports: Where parties agree to instruct a single expert, particularly in lower-value claims or where liability is admitted.

Trauma-Informed Methodology

A trauma-informed assessment differs from a general personal injury (PI) psychiatric evaluation in several key respects:

• Safety and trust: The assessment environment must prioritise the claimant’s emotional safety, with clear explanations of the process and control over breaks.
• Collaborative approach: The expert should avoid re-traumatising the claimant by adopting a non-judgemental, validating stance.
• Flexibility: Trauma survivors may struggle with linear narratives or recalling specific dates. The expert should allow for non-chronological disclosure and avoid pressuring the claimant.
• Multi-disciplinary input: In complex cases, a combined psychiatric and psychological assessment (or paediatric input where children are involved) can provide a more comprehensive understanding of the claimant’s presentation.

Practical Guidance for Solicitors

For legal practitioners handling coercive control claims, the following steps can strengthen the evidential foundation:

1. Early Instruction of a Trauma-Specialist Expert

Instructing an expert witness with specific experience in abuse injury claims—particularly those involving coercive control—can avoid common pitfalls such as diagnostic oversimplification or failure to recognise complex trauma. Early instruction also allows for timely collection of collateral evidence (e.g., medical records, witness statements) and reduces the risk of re-traumatisation during assessment.

2. Provision of Comprehensive Records

Expert witnesses require access to all relevant documentation, including:

• Medical records (GP, psychiatric, and psychological treatment notes).
• Police reports or criminal proceedings (where applicable).
• Statements from the claimant, family members, or professionals (e.g., social workers, teachers).
• Any contemporaneous evidence of coercive control (e.g., text messages, emails, or diary entries).

3. Preparation of the Claimant for Assessment

Claimants may feel anxious or distrustful about undergoing a psychiatric assessment. Solicitors should:

• Explain the purpose of the assessment and what to expect.
• Reassure the claimant that they can take breaks or pause the assessment if needed.
• Clarify that the expert is independent and not aligned with either party.
• Provide the claimant with an opportunity to ask questions in advance.

4. Anticipating Defence Arguments

Common defence strategies in coercive control claims include:

• Allegations that the claimant’s symptoms are exaggerated or fabricated.
• Arguments that the psychiatric injury predated the abuse or arose from unrelated causes.
• Challenges to the credibility of the claimant’s account, particularly where there are inconsistencies or gaps in memory.

A well-instructed expert witness can pre-empt these arguments by providing a robust, evidence-based opinion that addresses potential weaknesses in the claimant’s case.

Conclusion: The Evolving Landscape of Coercive Control Evidence

The Domestic Abuse Act 2021 has marked a turning point in how coercive control is understood in both clinical and legal contexts. For solicitors, barristers, and instructing parties, the Act underscores the importance of trauma-informed expert evidence—particularly in cases where psychiatric injury is the primary harm. By instructing specialists with experience in abuse injury claims, legal practitioners can ensure that the complexities of coercive control are fully captured in medico-legal reports, strengthening the claimant’s position in civil litigation, CICA matters, or group actions.

Trauma-informed medico-legal assessment from an experienced abuse injury expert witness remains pivotal in cases involving complex trauma presentations, limitation issues, or multi-disciplinary questions.