In Assessing the Truth: How Forensic Psychiatrists and Psychologists Evaluate Litigants, Dr. Mark Levy, a Distinguished Life Fellow of the American Psychiatric Association and ADA expert witness writes:
The gold bullion standard of evidence based opinion for forensic psychiatric and psychological experts is the ballistics expert who can say with reasonable “ballistic certainty” that a particular shell was fired from a particular gun…or it wasn’t. Of course, arriving at such a definite conclusion is more difficult in the behavioral sciences. However, with careful assessment of all available evidence, doing so is not only possible – it is probable.
The evidence that a forensic psychiatrist sifts through consists of medical, psychiatric and psychological records from periods of time both prior to, during and after the period of time when the incident or circumstance that was alleged to have emotionally and/or neurocognitively damaged the plaintiff occurred. These records can be both difficult to obtain and extensive – but once obtained and reviewed they are usually highly revelatory. Sometimes it is also helpful to obtain childhood medical records, even when evaluating adult plaintiffs. These records may help answer the question of whether this particular plaintiff is a person, who as a result of earlier emotional trauma, was particularly fragile when the event in dispute purportedly caused him or her to be damaged; or in contrast, whether the plaintiff is a highly resilient individual? Alternatively, the plaintiff may have a chronic mental condition (like the neurological disorder, Multiple Sclerosis) with its own waxing and waning natural course that is relatively independent of external events. If so, it is likely that such a condition would have produced emotional symptoms following the disputed events, whether or not the incident was actually damaging or had even occurred?