The CAT-MH™ not only provides a severity estimate, but also the uncertainty in that estimate so that the significance of change can be assessed for an individual patient.

Tests & Services

Adaptive Testing and CAT

Mental health measurement has been based primarily on subjective judgment and classical test theory. Typically, impairment level is determined by a total score, requiring that all respondents be administered the same items. An alternative to full scale administration is adaptive testing in which different individuals may receive different scale items that are targeted to their specific impairment level. Within adaptive testing, individuals’ initial item responses are used to determine a provisional estimate of their standing on the measured trait (e.g., depression, anxiety) to be used for subsequent item selection. This form of testing has recently emerged in mental health research (See Academic Press Tab).

Based on item response theory (IRT) procedures, estimates of items (e.g., difficulty, discrimination) and individuals (e.g., severity of depression) can be obtained to more efficiently identify suitable item subsets for each individual. This approach to testing is referred to as computerized adaptive testing (CAT) and is immediately applicable to mental health measurement problems. We have developed the first adaptive depression test based on multidimensional IRT, the CAT-DI, which can be administered adaptively, such that each individual responds only to those items that are most appropriate to assessing his/her level of depression.

The net result is that an individual is administered a small, optimal number of items without loss of measurement precision. The shift in paradigm is from small fixed length tests with questionable psychometric properties to large item banks from which an optimal small subset of items is adaptively drawn for each individual, targeted to their level of impairment. We therefore minimize patient burden, eliminate clinician burden, yet maximize precision of measurement. A special problem in mental health measurement is the inherent multidimensionality of the constructs of interest. To solve this problem we developed a new approach to CAT using a bi-factor multidimensional IRT model and derived a new item information function (IIF) that can be used in item selection. Results for the depression test reveal that the information in a 400 item depression bank can be efficiently extracted using an average of 12 items per patient (in 2 minutes) while maintaining a correlation of r=0.95 with the 400 item test results. In parallel, we have developed the first computerized adaptive diagnostic (CAD) screener for Major Depressive Disorder (MDD) which requires an average of 4 items, (in 40 seconds) yet maintains unprecedentedly high sensitivity of 0.95 and specificity of 0.87 for an hour-long clinician DSM-5 diagnosis of MDD. In essence, we can staff every primary care practice or emergency department with the equivalent of a trained clinician who can both screen and measure the severity of a wide variety of mental health disorders.

The combined CAD-MDD/CAT-DI requires approximately 2 minutes of time to administer on any internet connected device where patients can be screened and measured directly via the Internet in a secure and HIPAA compliant environment and interview results can be interfaced with an Electronic Medical Record system. CATs for depression, suicidality, anxiety and mania/hypomania have all been validated.

In two minutes each the severity of depression, anxiety, and mania can be measured with precision equal to what would have taken hours to achieve with traditional fixed length tests.

Precise Results

Results of a recent study conducted at a leading research hospital emergency department (ED) in 1000 patients not presenting for a psychiatric indication revealed a rate of 22% of MDD and 7% in the moderate to severe range in need of treatment for depression. 3% of patients generated a suicide warning based on suicidal ideation and intent, plan or behavior. At best, only a handful of these patients would have been identified based on routine ED practice. Furthermore, those with moderate to severe depression had a 300% increase in ED department visits in the prior year and a 400% increase in hospitalizations. These results have now also been replicated prospectively. Undiagnosed and untreated depression is clearly quite prevalent in our nation’s health care system and leads to dramatic increases in physical healthcare utilization and cost.

Culture and Language Adaptation

We have also carefully translated (forward, reverse and adjudicated) our entire 1008 item bank into Spanish and have all of our CATs available in both English and Spanish. In addition we have conducted a large-scale study of differential item functioning in Latino communities in Spain and the U.S. to identify items which may show cultural differences or bias. The net result is a more precise mental health measurement system which is capable of differentiating high and low levels of depression in both cultures and languages. Using the same technology we have determined how post-partum depression may differ from depression in general and whether or not somatic symptoms may not be good discriminators of high and low levels of depression in a perinatal population. We have conducted similar studies in Emergency Departments to further optimize our screeners and dimensional measures for patients with comorbid physical and behavioral health disorders.

Children and Parent CADs and CATs

Our most current 5-year study funded by the National Institute of Mental Health (now in its 4th year) will provide CADs and CATs for depression, anxiety, mania, suicidality, attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD) and conduct disorder (CD) in parallel for the child (ages 7-17) and their parent. These instruments will be specifically tailored to children and their parents based on a 2400 item bank with parallel items for children (1200) and their parents (1200) across these seven mental health domains.

Further CAD and CAT Testing and Translations

CATs and CADs for other mental health constructs such as Post Traumatic Stress Disorder (PTSD), Psychosis, Quality of Life, Functional Impairment and Substance Abuse are underway. Translations into Chinese, Portuguese, French and Italian have also been completed.


There are numerous applications of this new proven technology. Large-scale screening and monitoring of depression and anxiety in integrated primary care and behavioral health care settings is a natural application of this work and is already in practice in a number of major institutions. Insurers can now monitor the progress of patients through treatment without the patient needing to be in the clinic for testing. Frequent monitoring, even hourly in response to fast acting new pharmacologic treatments (e.g. ketamine) are possible because the same items are not repeatedly administered to the same patient. This also eliminates response set bias produced by repeated administration of traditional fixed-length tests. Patients seeking treatment can be screened by telephone so that waiting lists can be prioritized based on need rather than waiting time. Large- scale screening of adolescents in schools is now possible as a first step in prevention efforts using our existing tests, and soon our tests will be available for lower school students and their parents as well. In pharmaceutical studies, adaptive testing provides a method for easily identifying the most severely ill patients for enrollment as well as providing outcome measures with increased precision (i.e. signal to noise ratio) for identifying pharmacologic treatment effects. Large-scale molecular genetic studies (e.g. genome wide association studies) can use rapid adaptive testing to provide mental health phenotypes needed to better understand the genetic basis for psychiatric disorders and make advances in personalized medicine. CAT is also uniquely suited to detect falsification of responses that may be made to either give the impression of an illness (e.g. in a jail) or to mask the presence of an illness (e.g. in the military).