en Clinical Psychology Clinical Psychology Original Research Original Research <p> <strong> Abstract </strong></p><p> <strong> Background: </strong>Patients with addictions have many acute and chronic medical illnesses, both related and unrelated to their addictions. In spite of high incidence of </p><p>  substance-related disabilities, substance abuse is usually underdiagnosed in general </p><p>  hospitals. The objective of the present study was to investigate the frequency and pattern of substance use in patients with different medical complaints. </p><p> <strong> Methods: </strong>In this descriptive cross-sectional study , 1000 outpatients, aged 17 and </p><p>  older with various medical complaints were participated. The patients were attending </p><p>  neurology, ENT, nephrology, ophthalmology, cardiology, orthopedic, gastroenterology, surgical and dermatology clinics of four selected general hospitals. A 93 item clinicians-made scale, Rapid Situation Assessment of Drug Abuse in Iran, was used in this survey, and 30 items which focused on drug use were selected. </p><p> <strong> Results: </strong>8.7% of the patients reported lifelong or recent substance use and Opium </p><p>  was the most used substance, reported by 65.5% of the patients. Patients of neurology </p><p>  ,ophthalmology and orthopedic clinics showed the highest consumption . Smoking </p><p>  and injestion were the most frequent routes of substance used and the most reported </p><p>  pattern of use were 2 or 4 times a day and once a week. </p><p> <strong> Conclusions: </strong>The current cohort of substance users were relatively young, and </p><p>  many had reported detectable nervous system and orthopedic complications. Further </p><p>  research must investigate -their outcomes in the long term. </p> substance use, general hospitals, outpatients, opium, pattern of substance use 140 145 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-117&slc_lang=en&sid=1 Mehdi Nasr Esfahani mehdinassr@yahoo.com 2003194753284600778 2003194753284600778 No Department of Psychiatry. Rasoul Akram Hospital, Tehran, Iran Azizeh Afkham Ebrahimi afkhami@iums.ac.ir 2003194753284600779 2003194753284600779 Yes Department of Clinical Psychology. Tehran Psychiatric Institute, Satarkhan Niayesh. Shahid Mansouri St, Tehran.Iran Behrouz Birashk behrouz.birashk@gmail.com 2003194753284600780 2003194753284600780 No Iran University of Medical Sciences, Tehran-Iran Serveh Faraji Serveh_faraji@yahoo.com 2003194753284600781 2003194753284600781 No Oil Industry Counseling Center. Bandar Abbas- Iran Asma Aghebati asma_aghebati@yahoo.com 2003194753284600782 2003194753284600782 No Tehran Psychiatric Institute. Tehran-Iran