A psychoactive substance use disorder (ICD-10) was diagnosed in 28% of 1222 psychiatric referrals in six general hospitals in Finland. In the age group 35 o 50 years, 53% of men and 29% of women had a substance use disorder. In the age group 35 to 50 years, sociodemographic characteristics differentiated men diagnosed with substance use disorders from other male consultation patients, but women with substance use disorders were similar to other female consultation patients. Urgency (i.e., consultation required within the same day) was accentuated in referrals associated with substance use disorders. Of attempted suicides, 65% were related to substance use disorders. Use of sedatives or hypnotics had more frequently induced disorders in women with substance use diagnosis compared to men with diagnosis (30% vs. 13%; p < 0.01). Female consultation patients with substance use disorders more often than respective male patients were current mental health outpatients. In conclusion, the proportion of substance use disorders among psychiatric consultation patients was remarkably higher in the present study (28%) compared with the average provided by the earlier literature (12%), and therefore, at least in Finland, psychiatric assessment of general hospital patients should always include assessment for the presence of substance use disorders. If substance use is only looked for in patients who have social problems typical of advanced misuse, detecting female substance use might be impeded. Relation of attempted suicides to substance use disorders was confirmed. To prevent misuse of prescribed drugs detected particularly in female consultation patients, and to prevent attempted suicides, doctors' attention is called to prescriptions of sedatives and hypnotics.