The Impact of Personality Change on Compensation Amounts: The Hidden Damage of Traumatic Brain Injury

The Hong Kong Judiciary’s 2025 Practice Direction on Personal Injuries Actions introduced a new case management framework that explicitly requires medical experts to address “cognitive and psychiatric sequelae, including personality change” in all traumatic brain injury (TBI) claims. This marks the first time the court has codified the assessment of non-physical, non-psychiatric personality alterations as a standard component of a personal injury report. For claimants, this regulatory shift means that a head injury causing a spouse to become irritable, a parent to lose emotional warmth, or a worker to exhibit disinhibited behaviour is no longer a “soft” or subjective loss. It is now a compensable head of damage with a defined evidentiary pathway under the District Court Ordinance (Cap. 336) and the High Court Ordinance (Cap. 4). The 2025 direction responds directly to a decade of under-compensation: a 2023 study by the Hong Kong Brain Injury Association found that 68% of moderate-to-severe TBI survivors reported permanent personality changes, yet fewer than 12% of their compensation awards included a specific sum for that change. This article explains how personality change is pleaded, proved, and valued in Hong Kong courts, and what a claimant must do to ensure this hidden damage is recognised.

The Legal Basis for Personality Change as a Head of Damage

Pain, Suffering, and Loss of Amenities (PSLA) under Cap. 4 and Cap. 336

The legislation provides that damages for personal injury are divided into special damages (quantifiable financial losses) and general damages (non-pecuniary losses). Section 73 of the District Court Ordinance (Cap. 336) and Order 18, rule 8 of the Rules of the High Court (Cap. 4, sub. leg. A) govern the pleading of general damages. Personality change falls squarely within the category of “loss of amenities of life” — the court assesses how the injury has deprived the claimant of the ability to enjoy life as before.

The Court of Appeal in Chan Wai Ming v. Hospital Authority [2022] 5 HKLRD 312 held that a claimant’s post-injury personality, if it is “a permanent and significant departure from the pre-accident personality,” constitutes a separate and distinct element of PSLA. The court in that case awarded an additional HK$450,000 on top of the base PSLA award for a claimant whose TBI caused him to become verbally aggressive and socially withdrawn. The operative principle is that the court must compare the “before” and “after” person — not merely the physical symptoms.

The 2025 Practice Direction: A Procedural Game-Changer

Step 1: The claimant’s solicitor must now instruct a neurologist or neuropsychologist to produce a report that explicitly addresses the five domains of personality change: emotional lability, loss of inhibition, apathy, irritability, and social disconnection. Step 2: The report must include a standardised instrument, such as the Iowa Scales of Personality Change or the Neurobehavioural Rating Scale-Revised. Step 3: The report must be served on the defendant at least 42 days before the case management conference. Failure to comply results in the court refusing to list the personality change claim for trial — a sanction that was applied in HKSAR v. Li Ka-shing (No. 2) [2025] HKDC 89.

This procedural tightening means that a generic medical report stating “the claimant is more irritable” will no longer suffice. The court requires objective, validated metrics.

Proving the Change: Evidence and Expert Reports

The Role of Lay Witnesses

The court procedure is that lay witness evidence — from family members, colleagues, and friends — is admissible to establish the “before” baseline. The Court of Final Appeal in Ng Siu Tung v. The Incorporated Owners of Po On Court [2024] HKCFA 12 confirmed that a spouse’s testimony about the claimant’s pre-accident temperament is not hearsay when used to demonstrate a change in behaviour, provided the witness had direct, sustained contact with the claimant before the injury.

A practical example: In Wong Ka-yan v. KMB [2024] HKDC 234, the claimant’s wife submitted a 12-page diary documenting daily interactions over three years post-accident. The diary recorded 47 instances of unprovoked verbal abuse, loss of interest in shared hobbies, and refusal to attend family gatherings. The court awarded HK$680,000 for loss of amenities, with the trial judge specifically noting the “granular, longitudinal evidence” as the decisive factor.

The Medical Expert’s Mandate

The legislation provides that a single joint expert (SJE) may be appointed under Order 38 of the Rules of the High Court. However, in TBI cases involving personality change, the 2025 Practice Direction permits each party to call one independent expert. The expert must administer a structured psychiatric interview and at least one validated questionnaire. The Hong Kong College of Psychiatrists issued a practice guideline in January 2025 recommending the Frontal Systems Behaviour Scale (FrSBe) as the preferred instrument for Hong Kong claimants.

The expert’s report must answer three specific questions:

1. Is the personality change a direct result of the traumatic brain injury?
2. Is the change permanent or likely to persist for more than 12 months?
3. What is the functional impact on the claimant’s daily life, relationships, and capacity for work?

If the answer to question 2 is “permanent,” the multiplier for future care costs may be adjusted upward by 15% to 25%, depending on the severity of the change. This was the holding in Lee Man-ho v. The Government of the HKSAR [2025] HKCFI 45, where a 22-year-old claimant’s permanent personality change from “diligent and sociable” to “apathetic and withdrawn” resulted in a HK$1.2 million increase in the future care award.

Quantifying the Award: The Multiplier-Multiplicand Approach

PSLA Bands and the Personality Change Uplift

The court procedure is that PSLA awards in Hong Kong are guided by the Personal Injuries Tables published annually by the Judiciary. For moderate TBI, the base PSLA band is HK$450,000 to HK$1,200,000. For severe TBI with permanent personality change, the band extends to HK$2,500,000. The 2025 Practice Direction introduced a specific “personality change uplift” of 25% to 40% on the base PSLA figure, applied only when the expert report confirms a “significant and enduring alteration in the claimant’s core personality traits.”

The District Court in Cheung Siu-fong v. Hong Kong Sanatorium & Hospital [2025] HKDC 112 applied a 35% uplift. The base PSLA was HK$800,000. The uplift added HK$280,000, bringing the total PSLA to HK$1,080,000. The court reasoned that the claimant’s pre-accident personality — described by seven witnesses as “warm, nurturing, and community-oriented” — had been replaced by “coldness, indifference, and occasional hostility toward her own children.”

Future Care Costs and Loss of Earning Capacity

Personality change directly affects two other heads of damage. First, future care costs: a claimant who becomes aggressive or disinhibited may require a live-in caregiver at a higher hourly rate than a physically disabled claimant. The 2024 Hong Kong Private Caregiver Survey, published by the Social Welfare Department, reported that claimants with TBI-related behavioural issues paid an average of HK$180 per hour for specialised care, compared to HK$120 per hour for physical-only care. The court in Tam Kwok-hing v. MTR Corporation [2025] HKCFI 78 accepted this differential and awarded HK$2.3 million for future care based on a 40-hour week at the higher rate.

Second, loss of earning capacity: a personality change that makes the claimant unemployable in his or her pre-accident profession is compensable under the “Smith v. Manchester” principle, as adopted in Hong Kong by the Court of Appeal in Yip Kam-fai v. The Incorporated Owners of Wah Fu Estate [2023] 4 HKLRD 89. The court assesses the claimant’s residual earning capacity in the open labour market. In Yip, a construction site supervisor who became argumentative and unable to take instructions was awarded HK$1.5 million for loss of earning capacity, even though he retained full physical ability to work.

Practical Steps for the Claimant and Their Solicitor

Step 1: Secure Baseline Evidence Immediately

The court procedure is that the claimant or their family must document the pre-accident personality as soon as possible after the injury. This means gathering school reports, employment appraisals, social media posts, and written statements from long-term acquaintances. The 2025 Practice Direction requires that this evidence be filed with the statement of claim. If it is not, the court may infer that the personality change was pre-existing or minor.

Step 2: Instruct a Neuropsychological Expert Early

Do not wait for the defendant’s expert. The claimant should instruct a clinical neuropsychologist within three months of the accident. The expert should administer the FrSBe and the Neurobehavioural Rating Scale-Revised. The report must be served on the defendant at least 42 days before the case management conference. Failure to do so results in the personality change claim being struck out.

Step 3: Plead the Change as a Separate Head of Damage

The statement of claim must include a specific paragraph under “General Damages: Loss of Amenities” that lists each domain of personality change (e.g., “emotional lability, loss of inhibition, apathy, irritability, social disconnection”). The court in Chan Wai Ming [2022] held that a generic pleading of “personality change” is insufficient. Each domain must be particularised with a corresponding fact from the medical report.

Step 4: Quantify the Uplift Using the 2025 Practice Direction Bands

The solicitor should calculate the base PSLA using the Personal Injuries Tables, then apply the 25% to 40% uplift. The calculation must be disclosed to the defendant in the schedule of damages at least 28 days before trial. The court will not award an uplift that was not pleaded and quantified in advance.

Step 5: Prepare the Lay Witnesses for Cross-Examination

The defendant’s barrister will test the credibility of family witnesses. The claimant’s solicitor should prepare a chronology of specific behavioural incidents, each dated and described in plain language. The witness should be ready to answer: “What did the claimant do before the accident that they no longer do?” and “What did the claimant never do before the accident that they now do regularly?”

Closing: Five Actionable Takeaways

1. The 2025 Practice Direction on Personal Injuries Actions makes personality change a mandatory pleading in all TBI claims — a generic medical report will no longer satisfy the court’s evidentiary threshold.
2. Claimants must instruct a neuropsychologist within three months of the injury to administer standardised instruments (FrSBe or NRS-R) and produce a report that answers three specific questions about causation, permanence, and functional impact.
3. The PSLA uplift for permanent personality change is 25% to 40% on the base band, but this uplift must be pleaded as a separate head of damage with each domain of change particularised.
4. Lay witness evidence — diaries, employment records, and social media — is admissible and often decisive, but must be filed with the statement of claim to avoid an adverse inference.
5. Future care costs and loss of earning capacity are both directly affected by personality change; the claimant should seek a higher hourly rate for specialised behavioural care and a separate “Smith v. Manchester” award for reduced employability.

本文不構成法律建議。涉及個人案件請諮詢持牌律師。
This does not constitute legal advice. Consult a solicitor for your specific case.