There are five major patterns which explain the associations between somatic symptoms and substance-related disorders (SRD) in patients without organic disorders. They are withdrawal somatic symptoms, somatic symptoms related to co-morbid mental disorders, those related to co-morbid infectious diseases, functional intractable somatic symptoms (including somatoform disorders), and symptoms associated with intoxication. Those somatic symptoms that occur according to those five patterns might overlap each other, making it difficult for physicians to precisely grasp the associations between somatic symptoms and SRD. This results in a very complicated formation of various kinds of symptoms (syndrome). Furthermore, the clinical and social features of those patterns of associations differ between legal and illicit substances users. It should also be noted that such somatic symptoms associated with SRD may be affected by social factors such as cultural backgrounds or legal restrictions on such substances. Those factors differ according to each country, area, or community whose cultural backgrounds are somewhat specific. In those areas, psychosocial factors such as stigmas, prejudices, or feeling ashamed of one’s mental disorder (including SRD) also differ. Thus, it is important to take into account the effects of social or psychosocial backgrounds when evaluating and studying the associations between somatic symptoms and SRD. When clinicians confront patients with somatic symptoms and suspected SRD, they should presume which association pattern is the most significant problem for the patients, based on those psychosocial and biological information obtained from the patients themselves and their surroundings. This procedure might give an opportunity to clinicians for elucidating complicated associations between somatic complaints and SRD.