Substance Use Disorder (SUD) occupies a contested and richly theorized position within the depth-psychology corpus, where it functions simultaneously as a diagnostic category, a symptomatic expression of inner suffering, and a site of co-occurring psychopathology. The literature reveals three broad orientational stances. First, the psychodynamic self-medication tradition, represented most forcefully by Edward Khantzian, understands SUD not as a primary disease of willpower or pharmacological hijacking alone, but as a purposive—if ultimately self-defeating—attempt to regulate painful affects, manage ego deficits, and ameliorate psychiatric symptoms that otherwise render life intolerable. Second, the integrated-treatment tradition, exemplified by Lisa Najavits’s Seeking Safety framework, insists that SUD cannot be adequately treated in isolation from co-occurring trauma disorders; the intertwining of PTSD and substance use demands simultaneous clinical attention rather than sequential hierarchy. Third, a growing body of comorbidity research examines SUD in relation to neurodevelopmental conditions—ADHD and Autism Spectrum Disorder in particular—challenging any single-axis etiological model. Across all positions, the corpus foregrounds ambivalence, denial, the compulsion to repeat, nutritional depletion, and the long-term costs disguised by short-term relief as central clinical and theoretical concerns. The diagnostic taxonomy itself—abuse versus dependence, DSM-IV versus DSM-5—surfaces as a recurring methodological tension.