The second analysis in causation, particularly in negligence claims, is that of proximate cause. Proximate cause may appear to be a refinement on the question of causation itself, but in actuality it is a means of limiting the scope of a defendant's liability. In other words, while there may be some causal connection, the harm is too insignificant, remote, logically unrelated, or just beyond what a defendant should be held liable for. An example would be the claim that years of emotional distress were caused by an innocuous insult.
Typically, proximate cause centers on the question of whether the harm was foreseeable. This does not mean that the full extent of mental damage must be foreseeable, only the nature of the damage. This is tied closely to the principle of the thin skull or eggshell skull rule. Here the defendant may have no reason to know of a particular susceptibility of the plaintiff, but must take that plaintiff as he or she is found. This is typically applied where even dramatic or unusually persistent symptoms follow a relatively minor trauma. As a medical example, a patient with severe osteoporosis could suffer incapacitating injuries by a trauma that would not injure someone else; and, yet, the one who caused the trauma is responsible.
At the same time, the chain of causation can be broken by an intervening cause, and some jurisdictions are taking into account a plaintiff's unusual sensitivity to a particular stressor in order to limit liability.5 For example, did a minor car accident cause a psychotic breakdown in a person with borderline personality disorder, just because the psychosis followed the accident? What if a conversion disorder followed the accident? Or a disabling depression? A complete discussion on issuing opinions of causation is far beyond the scope of this article, but these examples illustrate how complex this undertaking can be.
Typically, opinions regarding mental damage are made by treating psychiatrists or other mental health providers about their patients who are injured or whose injury brought them to treatment. Attorneys will often refer a plaintiff to a psychiatrist both for treatment and expert opinion, under the assumption that the treating psychiatrist will be in the best position to give an opinion because he or she will have intimate knowledge of the patient and will have been in contact with him or her for some time.
A number of serious problems arise in this regard. First, the psychiatrist may not be trained in the evaluation of often complex legal cases. The initial treatment opinion and recommendations may have been given after a relatively brief interview, with a history that was almost exclusively based on the subjective reports of the patient. Rarely has the treating psychiatrist reviewed in advance recorded information, other opinions, past medical records, or statements from collateral sources.
Second, the treating psychiatrist inherently will tend to accept the patient's account and, in the absence of obvious inconsistencies, will become allied with the patient's interests. Indeed, it would be difficult for a treatment relationship to continue if the psychiatrist did not believe the patient or, even worse, expressed an opinion contrary to the patient's position in the claim.
Finally, the treating psychiatrist may suffer adverse financial consequences if he does not support the claim because, at times, payment of therapy bills may be contingent on such an opinion.
In contrast, independent forensic psychiatrists—while not without their own potential for bias—typically have access to a great deal of information from collateral sources and are not influenced by a doctor-patient treatment relationship. The forensic psychiatrist also may have a greater understanding of the law and how it may apply to a particular mental damage claim.
Even when an evaluation is conducted by an experienced forensic psychiatrist, the subjective nature of mental disorders and of mental damage claims must be emphasized. In this regard, 3 contaminating factors to the patient's history are commonly encountered, thereby distorting the account.
Psychiatric histories provided by a patient are in some sense a mythical narrative. Memories may decay over time and are influenced by a number of interfering factors, both biological and psychological. To some extent, all of us create personal myths or themes in which our story becomes part of how we want to see ourselves, or how we have learned to see ourselves over time. This may be an idealized, inflated self-view, or a self-deprecating one. A process of memory reconstruction takes place, with or without a theme, and this reconstruction is influenced by factors such as postevent information, suggestibility, biases, and environmental influences.
Social psychologists recognize the concept of attribution theory, which means that by identifying a cause for their distress, human beings can see themselves as less vulnerable even if that cause is erroneous. This can lead to finding reasons where no reasons exist, or ignoring the real reasons, or identifying reasons that are convenient.
Another commonly known process, secondary gain, can play a role in sustaining mental and physical symptoms. This refers to those, perhaps unexpected, environmental responses to symptoms or impairment that sustain a disorder by reinforcing it. Secondary gain may be triggered by financial reimbursement, attention from the family, or avoidance of less than satisfactory life conditions. Whatever the prompt, the history a patient provides is not necessarily consciously fabricated, but the effects of exaggeration and distortion from these factors can be powerful.