Introduction

The Court of Session’s decision in F against Gordon Chalmers and others ([2025] CSOH 23) marks a significant development in addressing complex cases involving multiple periods and sources of abuse, resulting in severe psychological harm. At the heart of the matter is the claim brought by an individual—hereafter the “pursuer”—who suffered extensive physical and sexual abuse in his early childhood at St Mark’s primary school by a priest, and later abuse during his secondary education at Fort Augustus Abbey. The case, involving multiple defendants initially, ultimately proceeds against the Roman Catholic Diocese of Galloway (the second defender), which accepted vicarious liability for the abuse perpetrated at St Mark’s. This judgment tackles not only the determination and division of liability but also establishes a nuanced method for apportioning damages where injuries, such as Complex Post Traumatic Stress Disorder (CPTSD), stem from multifactorial causes.

The pursuer, whose sustained abuse has resulted in lifelong vocational, educational, and personal impairments, faces challenges in substantiating precise causation in the presence of multiple adverse life events. In dealing with unreliable or fluctuating evidence—owing partly to the inherent difficulties in recollection and the psychological sequelae of abuse—the court has had to carefully weigh expert testimony amidst significant discrepancies. This judgment lays down new procedural and evidentiary principles for apportioning damages in cases where abuse at different times and settings contribute to a singular, indivisible psychiatric injury.

Summary of the Judgment

In his opinion, Lord Clark concluded that while both periods of abuse—the early childhood abuse at St Mark’s and the subsequent abuse at Fort Augustus Abbey—played contributory roles in the development of the pursuer’s CPTSD, the abuse at St Mark's was deemed the most grievous due to its repeated, penetrative nature and occurrence at a time when the pursuer was most vulnerable.

Given the multifactorial causation of the psychological injury, the court adopted an approach that diverges from the traditional multiplier/multiplicand method. Relying on precedents and the Blamire approach established in previous cases, the court instead opted for a lump sum calculation method to account for imponderable factors such as fluctuating employment prospects and unreliable personal testimony. Key components of the award include:

• A solatium award of £135,000 allocated to both past and future losses.
• A compensatory award for consequential losses amounting to £492,000, that together with solatium led to an overall award of £627,000 before accounting for previous payments.
• An intricate and discretionary approach to assessing interest on the damages, reflecting the complexities of calculating time periods in historical abuse cases.

In essence, the judgment finds that the abuse at St Mark’s contributed approximately 55% of the total causative impact, with the abuse at Fort Augustus and other adverse experiences contributing the balance. This division of causation was critical in determining the limits of liability and the quantum of compensatory damages.

Analysis

Precedents Cited

The judgment makes reference to several important cases and legal principles:

• Holtby v Brigham & Cowan (Hull) Ltd [2000] ICR 1086: This case introduced the notion of a “divisible” injury—wherein different exposures contribute cumulatively to a single adverse outcome. Lord Clark uses this principle to justify the apportionment of causation in a multifactorial injury claim.
• Hatton v Sutherland [2002] ICLR 613: The precedent further supports attacking the complexity of injuries when more than one exposure is responsible for the impairment sustained. This strengthens the court’s position that the delayed and multifaceted nature of abuse requires a nuanced apportionment strategy.
• JM v Fife Council: Widely referenced for its treatment of solatium awards and interest calculation, the case provided a framework for awarding damages in sexual abuse cases which were subsequently extended to account for the emotional and psychological harm described in this matter.
• Blamire v South Cumbria Health Authority [1993] PIQR Q1: This case was instrumental in acknowledging that if the evidential imponderables “cloud” the precise estimation of loss over time, a broad-brush or lump sum approach may be more appropriate.

Together, these precedents provided the legal backbone for the court’s decision to assess both the causation and the corresponding quantum of damages in a case where the injury is clearly divisible among several contributing factors.

Legal Reasoning

The court’s reasoning rested on several key points:

• Divisible Injury Principle: Recognizing that CPTSD in this case is multifactorial, the court established that liability for damages could be divided according to the relative contributions of various abusive events. The evidence suggested that while the abuse at both St Mark’s and Fort Augustus Abbey had serious impacts, the early and penetrative nature of the St Mark’s abuse carried more severe implications.
• Application of the Blamire Approach: Due to the inherent uncertainties regarding the duration and continuity of the pursuer’s employment history, the court rejected the conventional multiplication method as unsuitable. Instead, it favoured a lump sum method that adjusted for other contributing factors in determining past and future wage loss.
• Assessment of Expert Evidence: The judgment placed considerable weight on the testimony of expert witnesses, particularly those whose opinions aligned with the view that early childhood abuse (especially repeated penetrative abuse) has a disproportionate impact. When discrepancies arose in the expert opinions, the court chose to favor the evidence suggesting that abuse at St Mark’s was the predominant cause.
• Interest Calculation Discretion: The court meticulously examined competing theories regarding post-judgment interest. It ultimately endorsed a pragmatic approach modeled on JM v Fife Council, ensuring that the award takes account of historical inflation without “double counting” gains from potential investments.

Impact

This judgment is expected to have significant implications:

• Clarification on Divisible Causation: It cements a judicial method where courts can apportion liability between multiple sources of abuse. Future cases with similar multifactorial causation are likely to follow this precedent.
• Damages Calculation Methodology: By rejecting a strict multiplier/multiplicand approach in favour of a more flexible "Blamire" lump sum calculation, this judgment may influence future awards in cases where imponderable factors render traditional calculations inadequate.
• Enhanced Sensitivity in Abuse Cases: The decision underlines the necessity of treating historical abuse claims with considerable deference to the psychological complexities involved, encouraging a judicial environment that accommodates cognitive lapses and inconsistent evidence resulting from trauma.

Complex Concepts Simplified

Some of the technical legal concepts in the judgment are explained in plain language below:

• Divisible Injury: This concept means that an injury (here, the development of CPTSD) can be the result of several different causes. The court can assign a percentage to each cause to determine how much damage each period of abuse contributed.
• Blamire Approach: Refers to a method of calculating damages when it is not possible to pinpoint the exact loss due to various uncertainties. Instead of adding up specific earnings lost over time (as in the conventional method), the court awards a single lump sum that reasonably compensates for the inability to work.
• Solatium: This is compensation for non-economic loss, such as emotional suffering and pain, rather than direct financial loss. In this case, part of the award is meant to redress the enduring psychological harm.
• Interest on Damages: The court’s approach involves compensating the pursuer not just for the amount of damage recognized, but also for the “time value” of money lost because payments were delayed. The decision discusses applying varying rates to different components of the award.

Conclusion

In concluding, the Court of Session’s decision in F against Gordon Chalmers and others not only resolves a particularly painful abuse claim but also establishes clear precedents for handling multi-causal and complex psychiatric injuries. By embracing the divisible injury principle and endorsing the lump sum (Blamire) approach for calculating damages, the court has provided guidance for future cases where multiple abuse events contribute to a single enduring injury.

Key takeaways include the enhanced emphasis on precise apportionment of causation, a pragmatic method for losses where traditional calculations fail, and a detailed examination of interest accrual on compensatory damages. As such, this judgment is set to influence subsequent abuse litigation by ensuring that survivors are more adequately compensated in recognition of both their emotional suffering and the economic losses incurred.

Ultimately, this decision underscores the judiciary’s commitment to balancing the inherent uncertainties of traumatic abuse cases while ensuring that the most significant harm—especially that suffered at a time of greatest vulnerability—is recognized and appropriately remedied.