To distinguish between compensable, psychogenic injury and malingering, juries (in court cases) and administrative judges (in workers’ compensation and Social Security cases) must rely upon information and opinion provided in the testimony of expert witnesses. Accordingly, the standards for admissibility of expert opinion play an important role in the outcome of jury claims. In 1923, the federal courts concluded the Frye Rule (1) that specifically dealt with the admissibility of an expert’s opinion based on data from a predecessor of the modern polygraph or lie detector test. It concluded that the underlying “principle or discovery … from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.” Thus, the Frye General Acceptance Standards defined admissibility as “reliability”
and then deferred to an undefined “scientific community” for its “general acceptance.” This was essentially the law of the land until 1973.

On June 28, 1973, the Supreme Court held that sections, Federal Rules of Evidence (FRE) 702 (2), superseded the Frye Test because it found scientific admissibility too restrictive. Thus, the FRE ruling authorizes judges to admit medical or scientific testing if it will assist the judge or jury. Helpfulness is the touchstone of admissibility. A witness can be qualified as an expert “by knowledge, skill, experience, training, or education.” This rule did not expressly address the reliability of expert testimony and the trial judge was afforded great latitude (3). The trial judge, a layperson, had to decide if potentially controversial or perhaps ambiguous scientific evidence should be admitted to assist in clarifying a scientific issue for the jury. In view of many of the trial judges’ limitations of lack of scientific background, and so on, it is not surprising that many creative theories developed, leading critics of the legal system to claim that judges permitted “junk science” and thus “junk justice” (4).

Not unexpectedly, this came under the purview of the Supreme Court and led to the Daubert decision (5), in which it attempted to formulate standards for trial courts to apply in determining whether scientific testimony is sufficiently reliable to be allowed into evidence. According to Daubert, general acceptance of any technical or scientific method is linked to the peer-review literature and is based on scientific language, principles, and explicit scientific standards. Moreover, it also discussed statistical standards. Thus, speculation is unacceptable. Moreover, it mandated that the trial judge must be more vigilant and serve as “gatekeeper,” assuring that “scientific tests or evidence admitted is not only relevant but reliable.” It also encouraged FRE 706 permitting judges to appoint their own independent witnesses, especially resolving issues of scientific complexity (6). Rule 403 allows judges to exclude testimony if relevant expert opinions “will prejudice, confuse, or mislead the jury” (7). On December 1, 2000, Rule 706 of FRE was amended to include that testimony is the product of reliable principles and methods, based on specific facts or data, and has been applied reliably to the facts of the case (8).

While most state courts and laws conform with the Federal Rules of Procedure and Evidence, some do not, and therefore, the same testimony from a given expert witness might be admissible in some state courts but not in federal courts and vice versa. Over 40 states, however, have adopted these guidelines.

The workers’ compensation system, and Social Security disability system use their own set of rules which are usually decided by a judge or a panel of judges. Eligibility claims require that an injury has occurred so as to safeguard against fraud, yet workers’ compensation and Social Security disability systems have come to realize that physical trauma (alleged or perceived) may have an emotional consequence and, therefore, are more willing to permit recovery. In fact, the following cases (9, 10, 11, 12) provide awards for psychological trauma in the absence of physical injury.

The four most common psychogenic complaints seen in both state and federal litigation as well as the worker’s compensation system are (i) chronic pain, (ii) traumatic brain injury/cognitive encephalopathy, (iii) reflex sympathetic dystrophy (complex regional pain syndrome 1 and 2), and (iv) fibromyalgia.

Despite the fact that these symptoms are subjective and intangible and cannot be quantified, they may be responsible for a significant amount of the award (13).