Forensic Psychiatry

Comprehensive Analysis

Psychiatric Medical-Legal Assessment

Complex Medical Questions

Thorough Reports

Insightful Testimony

Leonard Weiss, M.D.   (512) 646-0880  Austin, Texas  Forensic Psychiatry  Contact Us About Your Case

Medical Body and Mind

At the Interface of Law, Psychiatry, and Medicine

Leonard J. Weiss, M.D. is Board-Certified in Medical Specialties of the Body, Brain, and Behavior Applied to Legal Questions


Board-Certified, ABPN

Forensic Psychiatry

Board-Certified, ABPN

Addiction Psychiatry

Board-Certified, ABPN

Internal Medicine

Board-Certified, ABIM

Brain Injury Medicine

Board-Certified, ABPN

Clinical Nutrition Fellowship

Memorial Sloan-Kettering

Learn More about Dr. Weiss

Forensic Evaluation and Medical Specialization

Overlap and Distinctions: 4 Areas of Medicine

Dr. Weiss draws on specialization in distinct psychiatric concerns as well as the overlap between emotional, mental health, and other diseases of the body.

When he is asked to evaluate the complex questions of psychiatry and the health of a litigant, he draws on the depth and breadth of his areas of expertise in Psychiatry, Forensic Psychiatry, Addiction Psychiatry, Brain Injury Medicine and Internal Medicine. He is also trained in Clinical Nutrition and is an expert about medical considerations in the use or misuse of vitamins and other supplements.

His forensic practice focuses on one or more of these specialties.

Dr. Weiss has been in medical practice as an internist for more than 40 years and Board-Certified in Forensic Psychiatry and Addiction Psychiatry for more than 25 years.

He has conducted thousands of psychiatric and medical assessments at some of the most respected institutions in medicine.

Objective Medical-Legal Findings Grounded in Rigorous Assessment and Medical Science

Proper diagnosis and treatment can be effective. However, if medical malpractice or negligence occurs, the results can be serious and damaging. Dr. Weiss makes no assumptions. He considers all possibilities and renders an objective opinion.

He is retained by both plaintiff and defense.

Medically Complex Cases: Psychiatry and Internal Medicine

Dr. Weiss is uniquely qualified to render knowledgeable and thoughtful medical-legal opinions by report and testimony.

He daws on multiple areas of medicine about complex cases that involve psychiatric conditions or allegations of disabling conditions, both mental and physical. 

Examples include co-morbid conditions such as Diabetes and Bipolar Disorder, Organ Failure and Drug Addiction, traumatic stress and conditions worsened by stress that is not diagnostically traumatic, prescribed pain medication, alcoholism, untreated and undertreated depression, COVID recovery, and/or mental illness.  Malingering is always a consideration.

The background of an individual’s medical condition can be disregarded or missed by psychiatrists unfamiliar or insufficiently trained in physical and organic disciplines.

Assessment – Independent Medical Examination

Review of Records

Report of Findings

Consultant as an Undisclosed Expert

Disclosed Expert Witness


Forensic Psychiatry and Addiction

Dr. Weiss’ forensic practice includes cases with factors involving substance abuse and/or addictive behavior. He is Board-Certified in Addiction Psychiatry and has been treating substance abuse disorders for more than 3 decades.

Practitioner Impairment

Dr. Weiss has also assessed addiction at the request of Licensing Boards in Texas where practitioner impairment is at issue. He is a HIMS AME assessing pilots in the context of possible addiction or substance abuse.

Addiction and Behavior

Some litigated events with a behavioral component reflect a person who alleges they have a Substance Abuse Disorder (e.g. drugs, alcohol, prescription medication) or Process/Behavioral Addictions (e.g., gambling, overeating, sexual addiction, or compulsivity.)

An addiction can impact judgment and behavior, which may be a factor in a lawsuit or criminal case.

Nutrition, Physical Health, Psychiatry and Behavior

Dr. Weiss has a career-long interest in nutrition and completed a Fellowship in Clinical Nutrition at Memorial Sloan-Kettering/Cornell some decades ago while a practicing internist. Before that, he minored in Nutrition at MIT and did bench nutritional research there as well as in medical school. After his Fellowship he sat for and passed the written and oral Boards for the American Board of Nutrition.

Diet can impact the efficacy of medications, mood, and overall health. Diseases (both psychiatric and physical) can be tied to nutrition, or malnourishment (inadequate nourishment), sugar/carbohydrate intake, and even the use and misuse of vitamins, dietary supplements, and “food faddism.”

In that regard, there are fallacies and misconceptions surrounding so-called “alternative medicine,” “integrative” or “functional” medicine which may or may not be practiced by a licensed physician or employ the scientific method.


Judicial System, Forensic Psychiatry, Consultation, and Expert Witness Testimony

As a psychiatrist and internist, Dr. Weiss is sought to opine in legal matters, which has been the case for more than 2 decades.

He has always been interested in the application of psychiatry/medicine to adjudicated matters. A portion of his time is now applied to Forensic Psychiatric cases, though his clinical practice remains his primary commitment.

Dr. Weiss was one of the first Psychiatrists to qualify for and achieve the American Board of Psychiatry and Neurology’s Board-Certification in Forensic Psychiatry in 1999.

Experience in the Interactions of Physical Health, the Body,
Brain and Behavior

Psychiatry and Internal Medicine Experience

Dr. Weiss began his medical career as an internist in Michigan, treating diseases of the body and mind in clinical practice. He turned his focus to a long-standing interest in psychiatry more than 20 years ago.

The relationship between elements of Psychiatry and Internal Medicine are a powerful and compelling focus of his medical practice.

In 1993, Dr. Weiss pursued his interest in Psychiatry and became Board-Certified by the American Board of Psychiatry and Neurology, with complementary Board-Certification in Addiction Psychiatry the following year.


In addition to patient care, Dr. Weiss has served on the faculties of renowned medical schools and Fellowships. At Rush University Hospital/Rush Medical College he was an instructor in Clinical Psychiatry, and to Fellows in Geriatric Medicine. He taught senior Psychiatric Residents about Addictionology (now referred to as Addiction Psychiatry) at Michael Reese Hospital in Chicago and Chicago Osteopathic Hospital. He has served on the faculty at Texas A&M Health & Science University.

Clinical Background

Dr. Weiss has treated patients in private practice in Chicago, Detroit, and Atlanta. In 2013 he opened Psychiatry Austin in Austin, Texas, where he has an active clinical practice.

MIT to Medicine

Dr. Weiss received his medical training after achieving a degree in Mathematics at MIT. It became apparent to him that he found medicine to be the more interesting field, though his mathematics background underscores Dr. Weiss’ interests in evaluating research and statistical medical findings of other experts in medicine.

Dr. Weiss’ Medical Specialties Explained

Internal Medicine
Internal Medicine is the treatment of medical conditions, including
diseases affecting the heart, blood, kidneys, joints, digestive systems, respiratory symptoms, vascular systems, substance abuse, and mental health.

American Board of Internal Medicine, ABIM (adaptation)

Psychiatry“Psychiatry is the branch of medicine focused on the diagnosis, treatment and prevention of mental, emotional and behavioral disorders…A psychiatrist is a medical doctor (an M.D. or D.O.) who specializes in mental health, including substance use disorders. Psychiatrists are qualified to assess both the mental and physical aspects of psychological problems. American Psychiatric Association (APA)
What is Addiction Psychiatry?
“Addiction Psychiatry is a subspecialty that involves focusing on evaluation and treatment of individuals with alcohol, drug, or other substance-related disorders, and of individuals with dual diagnosis of substance-related and other psychiatric disorders.”  American Board of Psychiatry and Neurology ABPN

We won on key aspects of the case. Your work was invaluable. Thank you.

David J. Tuckfield, Esq.

Attorney at Law, The AL Law Group

Sample Clients

  • Private attorneys (please ask for references)
  • Texas Physician Health Program
  • Professional Recovery Network
  • Texas State Board of Pharmacy (TSBP)
  • Texas State Board of Dental Examiners (TSBDE)
  • Texas Board of Veterinary Medical Examiners (TBVME), and the
  • Texas Optometry Board (TOB)


Medical-Legal Assessment

Consulting to attorneys about psychiatric and medical factors relevant to a case; conducting evaluations as a disclosed Expert Witness or undisclosed medical-legal consultant.

Independent Medical Examination (IME) of a party to the action, face to face, or by video. Collateral Interviews of relevant informants such as family members, medical staff, co-workers, depending on the case.

Reporting Medical-Legal Findings

  • Affidavits and Declarations
  • Written or verbal reports
  • Testimony

Reviewing Medical and Legal Records

Reviewing records sounds mundane but it is not. Records can contain valuable information and clues about a person’s health and mental state. Legal records reveal still more about the “story” painted by the examinee and others. 

Records Dr. Weiss routinely reviews:

  • Psychiatric
  • Treatment and diagnostic notes
  • Hospital, physician, specialists
  • Labs, radiology (MRI, CT), toxicology. As a Board-Certified Internist and Addiction Psychiatry specialist, Dr. Weiss is uniquely qualified to interpret these records
  • Depositions
  • Reports by other Expert Witnesses

Areas of Concentration

Psychiatric Disorders | Brain Injuries | Complex Medical Interactions | Addiction | Internal Medicine

Civil Litigation

  • Medical Malpractice | Standard of Care | Hospitals and Rehab
  • Traumatic Brain Injuries (TBI) | Brain Diseases (Dementia, Alzheimer’s)
  • Addiction
  • Psychiatric Disability
  • Testamentary Capacity | Competency to Enter into a Contract
  • Competency and Incompetency
  • Geriatric Psychiatry | Dementia | Diseases of the Elderly

Dr. Weiss is uniquely qualified to opine about the not-uncommon relationship of PTSD (Posttraumatic Stress Disorder) and TBI in individual cases.

Criminal Cases

  • Criminal Responsibility
  • Fraud: elder abuse, undue influence
  • Psychiatric factors in behavior
  • Malingering
  • Competency to stand trial

Figure, top of page: Inspired by Da Vinci’s “Vitruvian Man” ca. 1490. Licensed adaptation, Adobe Stock Images and Beryl Vaughan.