THE FOUR INCREASINGLY SEVERE TYPES OF PERSONAL ILLNESS TESTED ARE (1) DYSTHYMIC STATES, INCLUDING STATES OF DEPRESSION, ANXIETY, AND ELATION; (2) NEUROTIC SYMPTOMS; (3) INTEGRATED DELUSIONS, INCLUDING DELUSIONS OF GRANDEUR, PERSECUTION, AND CONTRITION; AND (4) DELUSIONS OF DISINTEGRATION. A SELF-REPORT INSTRUMENT, THE DELUSIONS-SYMPTOMS-STATES INVENTORY (DSSI) WAS USED TO MEASURE PERSONAL ILLNESS IN 42 MEN SERVING LIFE-SENTENCES FOR MURDER AT 3 PRISONS IN SCOTLAND; THEIR AVERAGE AGE WAS 29.7 YEARS AND THE MEAN LENGTH OF IMPRISONMENT WAS 4.8 YEARS. THE SAMPLE WAS COMPOSED ENTIRELY OF VOLUNTEERS. OF THE 42 COMPLETED DSSI FORMS, 39 WERE WITHIN THE HIERARCHICAL MODEL OF PERSONAL ILLNESS: 56.4 PERCENT WERE CLASSIFIED AT THE LEVEL OF DYSTHYMIC STATES, 35.9 PERCENT AT LEAST AT THE LEVEL OF NEUROTIC SYMPTOMS, 20.5 PERCENT AT LEAST AT THE LEVEL OF INTEGRATED DELUSIONS, AND 10.3 PERCENT AT THE LEVEL OF DELUSIONS OF DISINTEGRATION. THESE FINDINGS REPRESENT A REMARKABLY HIGH INCIDENCE OF PERSONAL ILLNESS AMONG MEN SERVING LIFE SENTENCES, PARTICULARLY WHEN COMPARED TO DSSI RESULTS FOR NONPRISONERS AND PSYCHIATRIC PATIENTS. THERE IS ALSO GOOD EVIDENCE OF AN INVERSE RELATIONSHIP BETWEEN LENGTH OF IMPRISONMENT AND THE PRESENCE AND DEGREE OF PERSONAL ILLNESS. SUPPORTING DATA AND REFERENCES ARE PROVIDED.