Pre-existing anxiety, depression, PTSD and sleep disturbance

Pre-existing conditions need to be analyzed carefully.

The Plaintiff has the onus of proving his/her claim.  When dealing with liability and fault, all the Plaintiff needs to prove is that on a balance of probabilities the defendants’ negligence caused or materially contributed to an injury.  Athey v. Leonati1996 CanLII 183 (SCC), [1996] 3 S.C.R. 458 at paras. 13-17.

This article will focus on anxiety, depression, PTSD and sleep disturbance, which were being claimed by the Plaintiff in Lewis v. Gibson, 2018 BCSC 1713 (CanLII).

Pre-existing injury – Defence approach:

  1. There is a longstanding pre-existing condition;
  2. All references to pre-collision symptoms will be highlighted;
  3. The said injury is more likely attributable to a pre-existing cause or event;
  4. All pre-existing life challenges of the Plaintiff will typically be highlighted (eg: drug use and opiod use);
  5. Regardless of the collision, the pre-existing injury would be ongoing;
  6. Regardless of the collision, the pre-existing injuries would have worsened in any event.
  7. Is there expert evidence that supports this theory?

If there is no medical evidence to suggest that the pre-existing injury would have, absent the MVA, deteriorated than the arguments and/or points above will likely not stand.

The Court in Lewis v. Gibson states the following:

No expert testified that absent the MVA the deterioration of the plaintiff’s pre-existing bouts of depression or anxiety issues were inevitable, much less to the degree they were post-MVA. This is fatal. An aggravation of a pre-existing injury is compensable, no matter how serious that pre-existing injury may have already been: Gordon v. Ahn at paras. 34.

It is important to note the test when assessing pre-existing injuries:

… Even though there may be several tortious and non-tortious causes of injury, so long as the defendant’s act is a cause of the plaintiff’s damage, the defendant is fully liable for that damage.  Blackwater v. Plint2005 SCC 58 (CanLII) at para. 78:

The evidence raised/presented in this case are noted:

  • Plaintiff had an anxiety disorder prior to the collision;
  • Suffered with ADHD and sleep disorder;
  • Experienced low mood and depressive symptoms
  • Pre-existing chronic right knee condition was present
  • Ongoing use of opiods and cocaine

If an aggravation of any pre-existing injury occurs as a result of the Defendant’s negligence, the Court states, the Defendant is liable.  The focus must be on the “aggravation” that has occurred post collision and if this can be successfully established, the injury is compensable.

Further facts:

Evidence of the Plaintiff prior to the collision:

  • Social
  • cheerful

Post collision the Plaintiff had become:

  • recluse
  • moody
  • withdrawn
  • avoidance behaviour
  • PTSD symptoms
  • Sleep pattern changes
  • Irritability
  • Hypervigilance
  • Poor subjective attention
  • Poor concentration

The Court in this case did not accept a PTSD diagnosis, which the Plaintiff’s experts had diagnosed.  One of the main reason for this is that the symptoms of PTSD were not debilitating to the degree of impairment, nor did they cause significant distress.  However, the Court was of the view that the symptoms were serious and did alter the Plaintiff’s life post collision.  The Court preferred the argument that the symptoms were more consistent with a diagnosis of depression and chronic anxiety.

The Court states:

While it has not been established the plaintiff had PTSD, he is nonetheless still compensable for the injuries caused by the MVA associated with this diagnosis consistent with Saadati, which holds that a medical label or diagnosis is not required to compensate for the effects of injuries sustained by a defendant’s negligence: see para. 31.

The Court further states:

Saadati is clear it is the effects of the injuries that are the basis of the Court’s causation analysis. In this regard, the aggravation of the plaintiff’s chronic anxiety and depression is clearly established.


[300]     In summary, the plaintiff is entitled to judgment as follows:

1. Non-pecuniary damages $120,000.00
2. Loss of past income earning capacity $45,000.00
3. Loss of future income earning capacity $300,000.00
4. Loss of housekeeping capacity $20,000.00
5. Cost of future care $26,703.50
6. Special damages $3,284.52
TOTAL $514,988.02


I would like to highlight the law that was quoted in this case because a careful review of it is very useful.  Don’t ever get too comfortable – reviewing the law over and over again is a process that will sharpen your skills when it comes to assessment and identifying risk on any claim.

[126]     The plaintiff does not need to establish that the defendant was the sole cause of the injury, as long as he establishes the defendant was a cause of the injury beyond the de minimus range. As summarized in Dhillon v. Song, 2016 BCSC 486 (CanLII):

[140]   The plaintiff must prove on a balance of probabilities that the defendants’ negligence caused or materially contributed to an injury. The defendants’ negligence need not be the sole cause of the injury so long as it is part of the cause beyond the range of de minimus. Causation need not be determined by scientific precision: Athey v. Leonati, 1996 CanLII 183 (SCC), [1996] 3 S.C.R. 458 at paras. 13-17.

[141]   The primary test for causation is the “but for” test. But for the defendant’s negligence, would the plaintiff have suffered the injury? This test recognizes that compensation for negligent conduct should only occur where a substantial connection between the injury and the defendant’s conduct is present: Resurfice Corp. v. Hanke, 2007 SCC 7 (CanLII) at paras. 21-23. Causation must be established on a balance of probabilities before damages are assessed. As McLachlin C.J.C. stated in Blackwater v. Plint, 2005 SCC 58 (CanLII) at para. 78:

… Even though there may be several tortious and non-tortious causes of injury, so long as the defendant’s act is a cause of the plaintiff’s damage, the defendant is fully liable for that damage. The rules of damages then consider what the original position of the plaintiff would have been. The governing principle is that the defendant need not put the plaintiff in a better position than his original position and should not compensate the plaintiff for any damages he would have suffered anyway:Athey.

[127]      As T.W.N.A. v. Canada (Ministry of Indian Affairs), 2003 BCCA 670 (CanLII) notes at para. 28, “[A] pre-existing condition, whether it is quiescent or active, is part of the plaintiff’s original position”. The court adds a further useful comment at para. 48:

… Whether manifest or not, a weakness inherent in a plaintiff that might realistically cause or contribute to the loss claimed regardless of the tort is relevant to the assessment of damages. It is a contingency that should be accounted for in the award. Moreover, such a contingency does not have to be proven to a certainty. Rather, it should be given weight according to its relative likelihood.

[128]     On this point, it is also helpful to set out the thin skull and crumbling skull doctrines as defined by the Supreme Court of Canada in Athey v. Leonati, 1996 CanLII 183 (SCC), [1996] 3 S.C.R. 458:

(5) The Thin Skull and “Crumbling Skull” Doctrines

[34]      The respondents argued that the plaintiff was predisposed to disc herniation and that this is therefore a case where the “crumbling skull” rule applies. The “crumbling skull” doctrine is an awkward label for a fairly simple idea. It is named after the well-known “thin skull” rule, which makes the tortfeasor liable for the plaintiff’s injuries even if the injuries are unexpectedly severe owing to a pre-existing condition. The tortfeasor must take his or her victim as the tortfeasor finds the victim, and is therefore liable even though the plaintiff’s losses are more dramatic than they would be for the average person.

[35]      The so-called “crumbling skull” rule simply recognizes that the pre-existing condition was inherent in the plaintiff’s “original position”. The defendant need not put the plaintiff in a position better than his or her original position. The defendant is liable for the injuries caused, even if they are extreme, but need not compensate the plaintiff for any debilitating effects of the pre-existing condition which the plaintiff would have experienced anyway. The defendant is liable for the additional damage but not the pre-existing damage: Cooper-Stephenson, supra, at pp. 779-780 and John Munkman, Damages for Personal Injuries and Death (9th ed. 1993), at pp. 39-40. Likewise, if there is a measurable risk that the pre-existing condition would have detrimentally affected the plaintiff in the future, regardless of the defendant’s negligence, then this can be taken into account in reducing the overall award: Graham v. Rourke, supra; Malec v. J. C. Hutton Proprietary Ltd., supra; Cooper-Stephenson, supra, at pp. 851-852. This is consistent with the general rule that the plaintiff must be returned to the position he would have been in, with all of its attendant risks and shortcomings, and not a better position.

[Underline in original.]

See also McKelvie v. Ng, 2001 BCCA 384 (CanLII); Heska v. Little, 2000 BCCA 255 (CanLII).

[129]     Gordon v. Ahn, 2017 BCCA 221 (CanLII), recently discussed the crumbling skull doctrine:

[33]      The use of the phrase “crumbling skull” to describe a plaintiff’s condition is, in any event, rarely helpful. As Major J. explained in Athey v. Leonati, there are no special rules or analyses that apply to claims made by plaintiffs who, before becoming victims of a tort, are affected by conditions that may deteriorate in the future. Damages are always to be assessed by reference to the situation that the plaintiff would be in but for the wrongdoing. Describing a plaintiff as coming within the “crumbling skull doctrine” does not eliminate the need for a complete analysis of the pain and suffering caused by the accident.

[34]      The judge found that there was “an inter-relationship between the pain that the plaintiff experienced from her physical injuries and her emotional or psychological problems”. He also found that her psychological problems “worsened because of the accident”. Even in cases where a plaintiff is suffering from serious chronic depression, an aggravation of the symptoms attributable to a tort is compensable: Sangha v. Chen, 2013 BCCA 267 (CanLII). In the present case, where the plaintiff’s symptoms were fairly minor before the accident, but developed into major depression as a result of the accident, it is clear that damages ought to have been awarded.

[36]      A proper analysis of the issue would have required the judge to consider the degree to which Ms. Gordon’s psychological and emotional health was damaged by the accident. Such an analysis would have required a detailed consideration of her pre-accident and post-accident mental health, as well as an assessment of the likelihood that a deterioration would have occurred even in the absence of an accident (see Laidlaw v. Couturier, 2010 BCCA 59 (CanLII)).

[130]     The crumbling skull doctrine dictates in part that if there is a measurable risk that a pre-existing condition would have detrimentally affected the plaintiff in the future, regardless of the defendant’s negligence, then this can be taken into account in reducing the overall award. Yoshikawa v. Yu (1996), 1996 CanLII 3104 (BC CA), 21 B.C.L.R. (3d) 318 (C.A.), clarifies that psychological injuries are to be analyzed in same manner as physical injuries:

[19]      One of the most important principles, for the purposes of this case, is the principle that, for the purposes of assessing damages, a tortfeasor must take the person injured by the tort in the actual condition of that person at that time. This has been called the “thin skull” principle. In its application to psychological problems it has been called the “egg shell personality” application of the principle. In my opinion there is no basis for giving a more restrictive application to this principle in cases where psychological injuries are suffered than would be given in cases where only physical injuries are suffered. A predisposition to suffer psychological injury in circumstances such as those brought about in a particular case by a defendant’s wrongful act does not relieve the defendant of the liability to compensate the plaintiff for the injuries represented by those psychological symptoms. Such relief could only occur, as I have said, if the psychological symptoms would have occurred in any event, even without the defendant’s wrongful act, through an application of the cause-in-fact test. …

[32]      … psychological injury will be compensable on the basis of a pre-existing thin skull, except only in cases where the psychological problem is so dominant as a pre-existing condition and the injuries sustained in the accident are so trivial that the accident can no longer be said to be a sufficient cause in law to support an award of damages on the basis of proximate cause.

[131]     This statement accords with the recent decision in Saadati v. Morehead, 2017 SCC 28 (CanLII), where Brown J. for the unanimous Court held that physical and psychological injuries should be subject to the same standard of proof: paras. 35–36.

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