Minnesota Multiphasic Personality Inventory (MMPI)
MMPI-2 Scoring & Interpretation
After the MMPI-2 is taken and scored, an interpretive report is constructed by the psychologist. Scores are converted to what are called normalized “T scores” on a scale ranging from 30 to 120. The “normal” range of T scores is from 50 to 65. Anything above 65 and anything below 50 is considered clinically significant and open for interpretation by the psychologist.
Throughout the years and over numerous research studies, a set of standard clinical profiles have emerged on the MMPI-2 which professionals call “codetypes.” A codetype is simply when two scales demonstrate significantly high T scores, with one being higher than the other. For instance, a 2-3 codetype (meaning that both Scale 2 and Scale 3 are significantly elevated) suggests significant depression, lowered activity levels and helplesness; furthermore the person may have become accustomed to their chronic problems and often have physical complaints.
Dozens of clinical codetypes are well-known and understood, as well as T scores that “spike” on a single Scale (such as a “Spike 4”, which would be a sign of a person who shows impulsive behavior, rebelliousness and poor relationships with authority figures). People with little or no psychopathology or personality concerns will not reach significance for any particular codetype. Most people with personality or mental health issues will usually have only one codetype, or a single codetype with a spike on a third scale.
Like all psychological interpretation, scores are analyzed in context of the individual being tested — not in a vacuum. For instance, we might expect a higher score in Hypomania (a measure of energy levels) in a teen, but it might be more unusual to see such a score in a senior citizen. Ideally, the MMPI-2 is being administered as a part of a battery of psychological tests, so that other testing can either confirm or deny the hypotheses the MMPI-2 may suggest.
Development of the MMPI
A lot of people comment on the fact that the questions on the MMPI don’t seem to make a lot of sense. On their own, they don’t. That’s because the questions don’t directly measure mental health problems or psychopathology. The items were derived from an original set of over 1,000 items the researchers collected in the 1930s from psychiatric textbooks of the time, personality inventories and clinical experience.
For an item to appear on a specific scale, it had to be answered significantly differently by a group of patients who were independently determined to have the problem of the scale’s focus. For instance, for the hypochondriasis scale, the researchers looked at a group of 50 hypochondriacs. They then had to compare this group with a group of people who had no psychiatric problems — a normal population that served as a reference group. The original MMPI was normed on 724 individuals who were friends or relatives of patients in the University Hospitals in Minneapolis, and who were not currently receiving treatment from a doctor.
The MMPI-2 is the result of an effort to update the MMPI, including rewording of many of the items (to reflect language changes), removing items that no longer were good scale predictors, and adding new items. It was then standardized on a new sample of 2,600 individuals from seven geographically diverse states and reflective of the U.S. Census. The MMPI-2 does not differ significantly from the MMPI in terms of how the test is administered, its clinical or validity scales.
The MMPI-2-RF (MMPI-2 Restructured Form) was published in 2008 and is an update to the MMPI-2; however it is not a replacement to the MMPI-2 because it was designed to better address current models of psychopathology and personality. The Restructured Clinical (RC) scales — which bear no connection to the MMPI-2’s original clinical scales (above) are: