Patients were admitted voluntarily for detoxification from drugs and for rehabilitation. Dependence on opiates and/or other drugs was confirmed for all patients before admission by clinical examination, self-reported history, and urine drug analysis and after admission by patient responses to methadone during the titration period. Interrogative suggestibility scales used with 43 subjects showed that suggestibility for the group as a whole was not significantly different when they were on opiates, withdrawing from opiates, or drug-free. Results indicated, however, that a subgroup of vulnerable individuals may have been more suggestible when under the influence of opiates. Further research is recommended to clarify the effects of drug intoxication and withdrawal on the reliability of confessions obtained from drug addicts interviewed in police custody. 23 references, 1 table, and 1 figure