The original authors of the MMPI were Starke R. Hathaway, PhD, and J. C. McKinley, MD. The MMPI is copyrighted by the University of Minnesota. The standardized answer sheets can be hand scored with templates that fit over the answer sheets, but most tests are computer scored. Computer scoring programs for the current standardized version, the MMPI-2, are licensed by the University of Minnesota Press to Pearson Assessments and other companies located in different countries. The computer scoring programs offer a range of scoring profile choices including the extended score report, which includes data on the newest and most psychometrically advanced scales—the Restructured Clinical Scales (RC scales). The extended score report also provides scores on the more traditionally used Clinical Scales as well as Content, Supplementary, and other subscales of potential interest to clinicians. Use of the MMPI is tightly controlled for ethical and financial reasons. The clinician using the MMPI has to pay for materials and for scoring and report services, as well as a charge to install the computerized program.

The original MMPI was developed in 1939 (Groth Marnat, Handbook of Psychological Assessment, 2009) using an [criterion] keying approach, which means that the clinical scales were derived by selecting items that were endorsed by patients known to have been diagnosed with certain pathologies. The difference between this approach and other test development strategies used around that time was that it was atheoretical (not based on any particular theory) and thus the initial test was not aligned with the prevailing psychodynamic theories of that time. The atheoretical approach to MMPI development ostensibly enabled the test to capture aspects of human psychopathology that were recognizable and meaningful despite changes in clinical theories.

The MMPI had flaws of validity that could not be overlooked forever. The control group for its original testing consisted of a very narrow portion of the population, mostly young, white, married people from rural areas. The MMPI also faced problems with its terminology not being relevant to the population it was supposed to measure. Furthermore, it became necessary for the MMPI to measure a more diverse number of potential mental problems, such as "suicidal tendencies, drug abuse, and treatment-related behaviors."

The first major revision of the MMPI was the MMPI-2, which was standardized on a new national sample of adults in the United States and released in 1989.The new standardization was based on 2,600 individuals from a more representative background than the MMPI. It is appropriate for use with adults 18 and over. Subsequent revisions of certain test elements have been published, and a wide variety of subscales was also introduced over many years to help clinicians interpret the results of the original clinical scales. The current MMPI-2 has 567 items, all true-or-false format, and usually takes between 1 and 2 hours to complete depending on reading level. It is designed to require a sixth-grade reading level. There is an infrequently used abbreviated form of the test that consists of the MMPI-2's first 370 items. The shorter version has been mainly used in circumstances that have not allowed the full version to be completed (e.g., illness or time pressure), but the scores available on the shorter version are not as extensive as those available in the 567-item version. The original form of the MMPI-2 is the 3rd most frequently utilized test in the field of psychology, behind the most used IQ and achievement tests.

A version of the test designed for adolescents, the MMPI-A, was released in 1992. The MMPI-A has 478 items, with a short form of 350 items.

A new and psychometrically improved version of the MMPI-2 has recently been developed employing rigorous statistical methods that were used to develop the RC Scales in 2003. The new MMPI-2 Restructured Form (MMPI-2-RF) has now been released by Pearson Assessments. The MMPI-2-RF produces scores on a theoretically grounded, hierarchically structured set of scales, including the RC Scales. The modern methods used to develop the MMPI-2-RF were not available at the time the MMPI was originally developed. The MMPI-2-RF builds on the foundation of the RC Scales, which are theoretically more stable and homogenous than the older clinical scales on which they are roughly based. Publications on the MMPI-2-RC Scales include book chapters, multiple published articles in peer-reviewed journals, and address the use of the scales in a wide range of settings. The MMPI-2-RF scales rest on an assumption that psychopathology is a homogenous condition that is additive.

Scales of the MMPI