Recently, a new infrequent response indicator, Frequency psychopathology, F(p), was developed for the Minnesota Multiphasic Personality Inventory - 2 (P. Arbisi B Y. Ben-Porath, 1995). F(p) has potential to provide users with a better understanding of elevations on Frequency (F) and F-back (FB) in settings where such elevations are commonly observed because it is less influenced by the confounding effects of distress and psychopathology. The study reports F, F(B), and F(p) scale characteristics from 308 male psychiatric inpatients by Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.) diagnosis. The mean F(p) scale score uniformly fell considerably below scores on F and F(B) and was independent of diagnosis. These findings provide further support for the use of F(p) as a sensitive index of profile invalidity in psychiatric populations.