THE DRUG-USING GROUP CONSISTED OF 27 BOYS, ALL RESIDENTS IN THE REHABILITATION UNIT OF A PSYCHIATRIC HOSPITAL DURING 1968 AND 1969. ALL HAD USED A WIDE VARIETY OF DRUGS, INCLUDING HEROIN, OVER A CONSIDERABLE PERIOD OF TIME, ALTHOUGH NONE WAS USING DRUGS AT THE TIME OF THIS STUDY. THE COMPARISON GROUP CONSISTED OF 20 YOUNG MEN, OF APPROXIMATELY THE SAME AGE AS THE DRUG-USING GROUP, WHO WERE RESIDENTS AT A DETENTION CENTER. ALL HAD AT LEAST FOUR COURT CONVICTIONS, AND NONE HAD ANY EXPERIENCE OF DRUG MISUSE. ALL SUBJECTS COMPLETED TWO PERSONALITY INVENTORIES, THE MINNESOTA MULTPHASIC PERSONALITY INVENTORY AND THE DYNAMIC PERSONALITY INVENTORY. THE SUBJECTS ALSO COMPLETED A SEMANTIC DIFFERENTIAL, IN WHICH THEY WERE ASKED TO DESCRIBE FOUR CONCEPTS ON SEVEN SCALES, FOUR FOR THE EVALUATIVE FACTOR, ONE EACH FOR THE POTENCY AND ACTIVITY FACTORS, AND A FURTHER ONE SUGGESTED BY MARKS (1965) AS A RISK FACTOR. THE FINDINGS REVEALED FOR SUBJECTS IN BOTH GROUPS THE CHARACTERISTIC PATTERN OF THE SOCIAL DELINQUENT ESTABLISHED THROUGH OTHER STUDIES -- A PERSON WHO HAS NOT DEVELOPED ADEQUATE SOCIAL ROLES. THE DIFFERENCE BETWEEN THE SUBJECTS IN THE TWO GROUPS WAS FOUND TO LIE IN THE GREATER VULNERABILITY TO ANXIETY AND DEPRESSION OF THE DRUG MISUSERS, WHO ARE MORE PASSIVE AND WISH FOR ACHIEVEMENT AT A FANTASY LEVEL. ON BOTH PERSONALITY MEASURES, DRUG USERS WERE SHOWN TO BE MORE DISTURBED EMOTIONALLY THAN THE MEMBERS OF THE DELINQUENT GROUP. DRUG MISUSERS WERE ALSO CHARACTERIZED BY GREATER VERBAL FACILITY AND A MORE MARKED INTEREST IN ARTISTIC AND INTELLECTUAL PURSUITS. IT IS NOTED, HOWEVER, THAT THE SIMILARITIES BETWEEN THE GROUPS TESTED ARE MORE MARKED THAN THE DIFFERENCES BETWEEN THEM. DATA FROM THE STUDY ARE PROVIDED, AND REFERENCES ARE GIVEN. (RCB)