Psychiatrist vs. Psychologist: How to Decide the Best Choice As An Expert Witness
When a medical-legal question has medical aspects to emotional states or behavior, such as chronic pain, traumatic brain injury, permanent physical disability (partial disability or total disability), a psychiatrist by virtue of his or her training, will have expertise to understand the behavioral consequences of physical medical conditions. If drug reactions or medication side effects affect behavior, the psychiatrist’s training in pharmacology will better qualify him or her to understand the behavioral consequences of drug/medication effects. The psychologist has no training in pharmacology and is not licensed to prescribe medications; the psychiatrist is. The psychiatrist is able to understand medical records by virtue of his medical training. The psychologist’s training does not include medicine and so his ability to understand the medical records is no greater than a layperson’s.
Often times, psychiatric symptoms are caused by organic pathology such as endocrine disruptions, cancer, or brain tumors, which the psychiatrist is able to consider and identify by virtue of his medical training. Psychiatrists have training in neurology and must demonstrate competence in neurology in order to be Board Certified as a psychiatrist. Psychologists do not have this training, nor does their license require expertise in neurology. Psychiatrists are trained to perform physical-medical examinations of patients to assist in diagnosis. Psychologists are not permitted to conduct physical-medical examinations. I refer you to case study A Head Trauma with a Surprising Twist which makes the point that a medical condition may become confused with a psychiatric condition, which a psychiatrist is trained to identify.
I have seen situations in which an attorney is faced with a client/litigant expressing symptoms of what appear to be the emotional consequence of the cause of action(s) in the litigation. For example, the litigant says to his or her attorney “(the event) made me so depressed. I just haven’t been the same since.” The attorney may believe the client suffers depression, which the attorney believes a psychologist may diagnose and testify about. The attorney then hires an Expert Witness to evaluate the litigant, with emotional distress and the proper approach to damages in mind. However, it is not within the legal training of the attorney to know if the experience of his or her client is (a) depression, (b) clinical depression, (c) treatable depression, (d) something else entirely, (e) related to the incident(s) at issue, (f) related to other psychiatric history of his or her client, and the list could go on. If the experience of the litigant is not depression but, say, an anxiety disorder, it may be related to the litigation itself, or uncertainty about the outcome of medical treatment (surgery for example) stemming from the event underlying litigation. The condition of the client/litigant may or may not be relevant to the lawsuit, but perhaps not in the way the attorney has expected. To present at trial a conclusion which a jury finds both relevant and reliable, would require the medical training of a psychiatrist, and preferably a forensic psychiatrist to: understand and synthesize medical records, conduct an examination if appropriate, take a medical history, confer with other doctors who may have been treating this individual if that is appropriate, to name only a few tasks which can be undertaken by a psychiatrist Board-Certified as a Forensic Psychiatrist by the American Board of Psychiatry and Neurology (which I am), who has the medical training and skill to offer as an Expert Witness.
 Please read the FAQ “What is a Psychiatrist?”