We have all treated a patient for whom you know you had the diagnosis correct, the medication regimen was working, and the patient adhered to treatment, but something was still “off.” There was something cognitively that wasn’t right, and you had identified subtle (and some overt) errors in the standard psychiatric cognitive assessment that didn’t seem amenable to psychotropic medications. Perhaps what was needed was neuropsychological testing, one of the most useful but underutilized resources available to help fine-tune diagnosis and treatment. Finding a neuropsychologist who is sensitive to the unique needs of patients with psychiatric disorders, and knowing what and how to communicate the clinical picture and need for the referral, can be challenging due to the limited availability, time, and cost of a full battery of standardized tests.
This article describes the purpose of neuropsychological testing, why it is an important part of psychiatry, and how to make the best use of it.
What is neuropsychological testing?
Neuropsychological testing is a comprehensive evaluation designed to assess cognitive functioning, such as attention, language, learning, memory, and visuospatial and executive functioning. Neuropsychology has its own vocabulary and lexicon that are important for psychiatric clinicians to understand. Some terms, such as aphasia, working memory, and dementia, are familiar to many clinicians. However, others, such as information processing speed, performance validity testing, and semantic memory, might not be. Common neuropsychological terms are defined in Table 1.
The neuropsychologist’s role
A neuropsychologist is a psychologist with advanced training in brain-behavior relationships who can help determine if cognitive problems are related to neurologic, medical, or psychiatric factors. A neuropsychological evaluation can identify the etiology of a patient’s cognitive difficulties, such as stroke, poorly controlled diabetes, or mental health symptoms, to help guide treatment. It can be difficult to determine if a patient who is experiencing significant cognitive, functional, or behavioral changes has an underlying cognitive disorder (eg, dementia or major neurocognitive disorder) or something else, such as a psychiatric condition. Indeed, many psychiatric conditions, including schizophrenia, bipolar disorder, posttraumatic stress disorder (PTSD), and major depressive disorder (MDD), can present with significant cognitive difficulties. Thus, when patients report an increase in forgetfulness or changes in their ability to care for themselves, neuropsychological testing can help determine the cause.
How to refer to a neuropsychologist
Developing a referral network with a neuropsychologist should be a component of establishing a psychiatric practice. A neuropsychologist can help identify deficits that may interfere with the patient’s ability to adhere to a treatment plan, monitor medications, or actively participate in treatment and therapy. When making a referral for neuropsychological testing, it is important to be clear about the specific concerns so the neuropsychologist knows how to best evaluate the patient. A psychiatric clinician does not order specific neuropsychological tests, but thoroughly describes the problem so the neuropsychologist can determine the appropriate tests after interviewing the patient. For example, if a patient reports memory problems, it is essential to give the neuropsychologist specific clinical data so he/she can determine if the symptoms are due to a neurodegenerative or psychiatric condition. Then, after interviewing the patient (and, possibly, a family member), the neuropsychologist can construct a battery of tests to best answer the question.
Which neuropsychological tests are available?
There is a large battery of neuropsychological tests that require a licensed psychologist to administer and interpret.1 Those commonly used in research and practice to differentiate neurologically-based cognitive deficits associated with psychiatric disorders include the Wechsler Adult Intelligence Scale-4th edition (WAIS-IV) for assessing intelligence, the California Verbal Learning Test-Third Edition (CVLT-3) for verbal memory and learning, the Brief Visuospatial Memory Test-Revised for visual memory, the Wisconsin Card Sorting Test (WCST) for executive functions, and the Ruff 2&7 Selective Attention Test for sustained attention.2 These and other commonly used tests are described in Table 2.1
Neuropsychological testing vs psychological testing
The neuropsychologist will use psychometric properties (such as the validity and reliability of the test) and available normative data to pick the most appropriate tests. To date, there are no specific tests that clearly delineate psychiatric from nonpsychiatric etiologies, although the Screen for Cognitive Impairment in Psychiatry (SCIP)3 was developed in 2013 to explore cognitive abilities in the functional psychoses; it is beginning to be used in other studies.4,5 The neuropsychologist will consider the patient’s current concerns, the onset and progression of these concerns, and the pattern in testing behavior to help determine if psychiatric conditions are the most likely etiology.
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