How can you tell if someone is exhibiting signs of Substance Use Disorder (SUD)? Many people aren’t aware that addiction and substance use is a clinically diagnosable disease. However, the criteria may not fit perfectly into an individual’s unique and personal experience. Symptoms vary on a case-by-case basis, and an individual need not experience all symptoms to receive a diagnosis. In fact, the severity of Substance Use Disorder is scaled based on the number of symptoms an individual experiences. Let’s discuss this scale, symptoms, and the contributing factors of this serious disorder.