Psychological Testing versus Clinical Examination
Psychological testing is actuarial - that is, it compares an individual's responses with those of other persons who have taken the same test and either had no psychiatric condition or had psychiatric conditions defined by clinical examination and diagnosis.
Psychological testing may be most helpful in defining aspects of personality. In some cases the presence of disordered thinking may be only evident under conditions of extreme stress. Psychological testing may be of value in that circumstance. It may also be of value in assessing other problems with thinking, such as those which occur following traumatic brain injury.
Psychological testing may have applicability in judicial settings. It may be helpful in explaining certain behaviors, such as behaviors of victims following a crime, recanting of statements, and in some cases a predisposition to offer a false confession in the face of coercive interrogation. It must always be corellated with the findings of an experienced clinician who has reviewed the records. Whenever possible the consultant should perform an examination of the person of interest.
Psychological testing results can sometimes be manipulated by those taking the tests if they have a high degree of sophistication. Although many tests include "validity scales" these may not identify false results in a highly sophisticated person who quickly perceives the purpose of the test (testing for likely pedophilia is an example of where this can occur).
Because of these limitations, psychological testing results do not "prove" the presence or absence of a psychiatric condition. Their limitations should always be disclosed when results are brought into evidence.
Only doctoral level psychologists are licensed to report on the findings of most, but not all psychological tests. Psychiatrists are familiar with reports of psychological tests and are qualified to provide an explanation of their applicability and limitations in a judicial setting.
Clinical evaluations rely heavily on information provided by the person being interviewed. This is an area of weakness. To the maximum extent possible, efforts should be made to corroborate symptoms through information provided by others. In some circumstances living situation or the nature of the symptoms may limit this possiblility.
In the absence of corroborating testimony, experts will examine consistency of reported symptoms with the known character of psychiatric disorders, consistency of reports across time, and the manner in which information is provided by the interviewee. Experienced forensic psychiatrists use open ended questioning to assess whether reported symptoms appear to be "learned, practiced, or scripted." Psychiatrists must avoid any judgment of "truthfulness" of information they obtain, but they can comment on the nature of the information and whether it seems consistent or inconsistent with the alleged circumstances.