A qualified healthcare professional, such as a doctor or addiction specialist, can diagnose drug addiction. They may use diagnostic criteria from the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to make a diagnosis. These criteria include factors such as drug use that interferes with daily life, continued use despite negative consequences, and withdrawal symptoms when drug use is stopped. It is important to seek a professional opinion and not self-diagnose, as drug addiction is a complex condition that requires specialized care.