The complicated interaction among nutrition, medical treatment, and psychological health, especially in the case of SUDs, emphasizes the need for an integrated treatment plan for recovery. SUDs are commonly associated with a variety of mental health conditions, further compounding the challenges during treatment and recovery. This chapter discusses dietary contributions to better mental health by delineating relationships between nutrients, pharmacological treatments, and behavioral interventions in addressing mental health problems and SUDs. It underlines, especially, the neurobiological mechanisms through which some dietary components—in the shape of amino acids and growth regulators—meet brain functioning and mood modulation. This approach addresses an integrative viewpoint where pharmacological, nutritional, and behavioral interventions become essential for a comprehensive treatment of SUDs aimed at long-lasting promotion of recovery. Through the examination of the latest research and therapeutic practices, this work undertakes an attempt to emphasize the potential of diet and nutrition to act as adjuncts to traditional treatment modalities with the ultimate goal of improving patient outcomes in the management of SUDs, mental health disorders, and related comorbidities.