Psychology Expert Witnesses: The Ultimate Guide

Psychologists are mental health professionals that use psychotherapy and behavioral interventions to treat patients with mental and emotional suffering. Because of the array of psychology subspecialties, psychology expert witnesses can opine on a wide variety of cases.

Psychology Expert Witnesses: The Ultimate Guide

ByDr. Tuan Nguyen

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Published on August 29, 2019

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Updated onFebruary 2, 2023

Psychology Expert Witnesses: The Ultimate Guide

Attorneys frequently retain psychologists as expert witnesses to opine on a plaintiff’s cognitive, emotional, or psychological damages suffered as a result of a personal injury, traumatic event, malpractice, or negligent care. Psychology expert witnesses can also evaluate a defendant’s competency to stand trial in criminal cases and opine on a variety of issues in civil, family, and employment cases.

Here, we cover how to decide if a psychology expert is right for your case, the range of possible expert subspecialties within psychology, and the types of cases for which these specialties are most effective.


  1. Determining Whether You Need an Expert in Psychology or Psychiatry
  2. Academic Credentials: Choosing Between a PhD and a PsyD
  3. Specialized Training: The Best Psychology Expert For Your Case
    1. Clinical Psychology Experts
    2. Forensic Psychology Experts
    3. Neuropsychology Experts
    4. Counseling Psychology Experts
    5. Child & Adolescent Psychology Experts
    6. Geropsychology Experts
    7. Industrial & Organizational Psychology Experts
  4. Where to Find Psychology Expert Witnesses
  5. The Psychology Expert Witness Report
  6. Psychology Expert Witness Fees


Determining Whether You Need an Expert in Psychology or Psychiatrist Expert Witness

Psychologists and psychiatrists are often thought of as interchangeable, as much of their purpose and training overlap. But there are critical differences between the two professions that attorneys should consider when deciding what type of expert witness to retain for their case.

The primary difference between psychiatrists and psychologists is that psychiatrist expert witnesses are trained medical doctors, meaning they can prescribe medication. If your case requires an expert witness to opine on a patient’s medication dosage or the side effects of antipsychotic drugs, etc., a psychology expert is probably not your best bet. As medical doctors, psychiatrists are also trained to recognize the psychological and behavioral effects of medical illnesses (e.g., cancer, chronic illnesses, neurologic disorders) and non-psychiatric medications (e.g., steroids, chemotherapy agents, antiparkinsonian agents, cardiac medications).

Psychologists are, however, qualified to conduct psychological testing that can be critical in a variety of cases. Only psychologists are trained to administer and interpret certain types of psychological tests, making them ideal for conducting independent medical examinations assessing a person’s mental state, their capacity to provide testimony, or the extent of their mental, emotional, or psychological damages.

When deciding whether or not you need a psychology expert witness, take into consideration the type of case you are working on and the professional training of the parties involved. Psychology experts provide different advantages in civil versus criminal cases. If you are working on a medical malpractice or negligence case, make sure to retain an expert with credentials that match the defendant in question as closely as possible.

Academic Credentials: Choosing Between a PhD and PsyD

Of course, when selecting an expert witness—whether for consulting or testifying purposes—it is imperative to select a well-credentialed professional. Only psychologists with either a PhD or a PsyD are eligible to become legally licensed and board-certified by the American Board of Professional Psychology (ABPP). But each of these psychology backgrounds is best suited for different types of expert witness support.

A PhD is a Doctor of Philosophy whereas a PsyD is a Doctor of Psychology. Psychologists with a PhD are trained with more emphasis on academic research. Psychologists with a PsyD are trained with more emphasis on clinical work. If your case requires an expert witness with more clinical experience, your best bet is to retain a PsyD.

However, if you are looking to wow the jury with an expert’s prestige, you may want to consider retaining a PhD in psychology. Psychology PhD programs are generally more competitive than PsyD programs. The number of students selected for a psychology PhD program is typically less than 10 compared to a PsyD program, which can reach as high as 100. Doctorate-level psychology programs at prestigious academic institutions typically award a PhD degree.

Ultimately, the right psychology expert for your case will be one with the most relevant subspecialty and professional experience to opine on the case material.

Specialized Training: The Best Psychology Expert For Your Case

According to the American Psychological Association (APA), there are 18 recognized psychology specialties and proficiencies: Clinical Neuropsychology, Clinical Health Psychology, Psychoanalysis in Psychology, School Psychology, Clinical Psychology, Clinical Child Psychology, Counseling Psychology, Industrial-Organizational Psychology, Behavioral and Cognitive Psychology, Forensic Psychology, Couple and Family Psychology, Geropsychology, Police & Public Safety Psychology, Sleep Psychology, Rehabilitation Psychology, and Group Psychology/Group Psychotherapy.

Many of these specialties and proficiencies overlap in their training requirements and treatment methods. For the purpose of this article, we have provided detailed explanations of the most common psychology legal expert specialties and what kinds of cases those psychologists are best suited to consult as expert witnesses.

Clinical Psychology Experts

Clinical psychologists are specialized in diagnosing and treating mental, behavioral, and emotional illnesses with behavioral and psychoanalytic therapy. Clinical psychologists work in a wide variety of settings, including private practice, clinics, hospitals, schools and universities, and rehabilitation facilities.

Clinical psychologists treat mental health problems including anxiety, depression, schizophrenia, obsessive-compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), post-traumatic stress disorder (PTSD), dissociative identity disorder, military mental health, and personality disorders.

Expert witnesses in clinical psychology are helpful for performing independent medical examinations for cases involving severe emotional distress secondary to traumatic experiences including sexual assault, domestic abuse, violence, human trafficking, loss and grief, trauma from burn injuries, etc. Clinical psychologists can also discuss the standards of care for inpatient mental health treatment, perform pain and suffering evaluations, and assess suicide-risk.

Browse experts in clinical psychology here

Forensic Psychology Experts

Forensic psychologists specialize in applying clinical psychology principles to legal matters. In addition to a background in clinical psychology, forensic psychologists are trained in forensic assessment instruments that investigate psycholegal questions.

Forensic psychology expert witnesses conduct forensic evaluations and write expert reports regarding criminal profiles, assessments of an individual’s future risk to himself or others, and treatment recommendations. They may also testify regarding a person’s competency to stand trial, a defendant’s criminal responsibility based on personality disorders or altered mental status, and malingering or feigned symptoms (e.g., factitious disorder).

Expert witnesses in forensic psychology are critical in criminal cases that require mental status/insanity assessments or personality disorders related to criminal accusations. They are also helpful in cases involving DSM-5 diagnostic criteria, intellectual and neuropsychological testing, inadequate informed consent, or incompetence in will disputes.

Browse experts in forensic psychology here

Browse experts in forensic psychiatry here

Neuropsychology Experts

Neuropsychologists assess, diagnose, and treat psychological disorders associated with brain-based conditions.

Neuropsychology experts are frequently brought on as damages experts in personal injury and medical malpractice matters—particularly traumatic brain injuries (TBI) or strokes. In personal injury or medical malpractice cases involving car accidents or concussions (including post-concussion syndrome), neuropsychology expert witnesses are qualified to assess a plaintiff’s memory, attention, learning, processing speed, and abstract reasoning. Based on the results of these tests, these experts can opine on the impact of the injury or malpractice on a person’s day to day functioning and propose on-going treatment plans.

Neuropsychologists may also diagnose learning disabilities including autism/autistic spectrum disorder, Down Syndrome, Alzheimer’s disease, dementia, and various other conditions. In cases involving child developmental delays secondary to injury or malpractice, a neuropsychology expert can opine on impairment to the child’s intellectual, academic, attention, language, visuospatial, memory, and fine motor skill capacities.

Browse experts in neuropsychology here

Counseling Psychology Experts

Counseling psychologists focus on how people function as individuals and in their relationships with others. In this capacity, counseling psychologists can work as expert witnesses in cases dealing with child trauma, marriage and family dynamics in divorce proceedings or custody battles, and opine on interpersonal relationships insofar as they help the judge or jury understand the case facts. They can also opine on how plaintiffs respond to bereavement including spousal grief, parental grief, infant or child death, traumatic loss, or cases of murder or suicide.

In addition, many counseling psychologists are vocational rehabilitation specialists who can conduct career assessments on plaintiffs who have suffered life-altering injuries. They can assess the plaintiff’s impairments and functional restrictions secondary to their injuries and opine on their post-injury working capacity.

Browse experts in counseling psychology here

Child & Adolescent Psychology Experts

Clinical child psychologists specialize in understanding the psychological needs of infants, toddlers, children, and adolescents within their social contexts. As expert witnesses, child and adolescent psychologists can discuss how the family and other social contexts influence the socio-emotional adjustment and behavioral adaptation and health status of children. They can also discuss the impact of aggression, bullying, addictions, sexual assault, and domestic abuse on the cognitive and behavioral development of children and adolescents.

Clinical child psychology expert witnesses are helpful for cases that require independent medical evaluations on children with mental health problems and recommendations for therapeutic interventions.

Browse experts in child & adolescent psychology here

Geropsychology Experts

Geropsychology or geriatric psychology experts focus on adult development and aging. Their specialized knowledge includes the evaluation of the behavioral and mental health of the elderly, the psychological effects of chronic illnesses, psychopathology, neuroscience, and functional changes. Geropsychologists practice in outpatient and inpatient medical, mental health, and long-term care settings such as nursing homes or assisted living facilities.

Geropsychology expert witnesses are consulted for cases involving elder abuse and will disputes. They can conduct cognitive and functional performance testing on elderly individuals, evaluate their decision-making and functional capacities (especially those with memory loss) and assess their future risks.

Browse geriatric psychology experts here

Industrial & Organizational Psychology

Psychologists who specialize in industrial and organizational psychology focus on human behavior in the workplace. They usually work in human resources departments in the business, industry, labor, public, and academic sectors.

Industrial psychology expert witnesses are generally consulted for cases involving workplace disputes, employment discrimination, and workers’ compensation evaluations.

Browse industrial & organizational psychology experts here

Where to Find Psychology Expert Witnesses

Many psychology experts have interdisciplinary training and work experience, making it challenging for attorneys to navigate their options for expert witness support and find an expert with the right background to opine on the specifics of their case. That being said, there are a few ways to go about finding and retaining a psychology expert witness for your case.

The most qualified psychology expert witnesses are those that not only have the appropriate academic credentials and licenses but are also affiliated with industry organizations. If you are searching for a psychology expert witness on your own, a good place to start is the American Psychological Association as well as other state, provincial, and territorial psychological associations.

There are also psychologists who advertise their consulting services in expert witness directories. These directories offer attorneys a quick way to search a volume of psychology experts in various subspecialties who are actively looking for legal consulting opportunities. However, directories come with a few strings attached.

Not every expert that appears in an expert witness directory is actively practicing. Many are retired or have chosen to make their full-time job serving as a psychology expert witness. This generally weighs against an expert’s credibility in court and has the potential to adversely affect the outcome of your case. In addition, experts listed in directories may not be fully background checked. Often times, because these experts frequently appear in court, they may have Daubert or Frye challenges against them which could come back to haunt any attorney who retains them. Before choosing to retain an expert through an expert witness directory, it is critical to perform a full background check to ensure the expert has no skeletons in the closet.

The simplest and most effective way to find a psychology expert witness is through an expert witness referral service. Expert witness referral services handle the entire expert search process, including background checks, freeing your time to work on your case. This is a particularly good choice if you’re looking for a psychology expert with experience in a narrow topic, or if you are in a time crunch and need a stellar expert fast. Referral services, like the Expert Institute, custom recruit psychology expert witnesses based on the fact pattern of the case and the attorney’s preferences for location, hourly rate, litigation experience, publications, licensures, and more.

Historically, a common contractual practice among referral services has been to charge attorney clients a marginal rate on top of the expert’s hourly rate. The major issue with this practice is that the costs the attorney pays in the long-term are significantly greater than if the expert was identified through other channels. While this billing structure still holds for many expert witness referral services, Expert Institute only charges a one-time fee to execute a custom expert search.

The Psychology Expert Witness Report

Psychology expert witness reports typically begin with the case facts and an explanation of the psychology expert witness’ function in the case. The expert should discuss their academic and/or clinical psychology background and experience. Psychology experts should take extra care to outline their qualifications to conduct the assessments they intend to perform so as not to raise a Daubert or Frye challenge in court.

The psychology expert report should include an in-depth background of the evaluee. The psychology expert witness should indicate what information they gathered and how they received it. This could include interviews with the evaluee, their family members, health and legal professionals, and pertinent records. The psychology expert should consult any relevant history from the evaluee that can help contextualize the case issues for the judge and jury.

A psychology expert report should also specify the limits of confidentiality. The psychology expert witness is required to inform the evaluee that they will be submitting a written report based on their evaluations. However, required reports will be submitted whether or not the evaluee consents to being evaluated.

Ultimately, the psychology expert witness should discuss their findings and provide a conclusive assessment of the evaluee. Depending on the facts of the case and the expert’s purpose, this could include a discussion of the evaluee’s mental functioning, behavior, cognitive functions, capacity to stand trial, decision-making capacity, pain and suffering evaluations, or treatment needs.

Psychology Expert Witness Fees

Psychology expert witness fees can vary based on several factors including the psychologist’s specialty, the number of licenses they have, their years of experience, their location, and how specialized or rare their experience is.

In terms of what you can expect to pay a psychology expert, the national average fee for an initial case review by a psychologist is $303.16 per hour. The average hourly deposition fee for a psychology expert is $368.76 and the average hourly fee for a psychology expert’s court appearance is $437.21. To view the average fees of psychology experts in each state, check out our Expert Witness Fee Calculator

About the author

Dr. Tuan Nguyen

Dr. Tuan Nguyen

Dr. Nguyen’s clinical experience spans the breadth of mental health and psychopharmacology as well as neurology and internal medicine. His research experience includes both cellular and cognitive neuroscience at Harvard Medical School, Tufts University, and the University of California.

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