Which disorder features persistent thoughts that cause significant anxiety?

The disorder that features persistent thoughts causing significant anxiety is indeed found within the category of Obsessive-Compulsive or Related Disorders. This group of disorders is characterized by the presence of obsessions, which are intrusive and unwanted thoughts that lead to marked anxiety or distress. Individuals with this condition often engage in compulsive behaviors or mental acts in an attempt to reduce the anxiety associated with these obsessions, even though these compulsions do not provide real pleasure or satisfaction and may even exacerbate the distress.

In contrast, the other options represent different forms of anxiety-related issues. For instance, Substance-Induced Anxiety Disorder is associated with anxiety symptoms that are directly related to substance use or withdrawal. Generalized Anxiety Disorder involves excessive worry about a variety of everyday issues, but it does not specifically revolve around intrusive obsessive thoughts. Other Specified Anxiety Disorder encompasses anxiety symptoms that don’t fit the full criteria of other specified anxiety disorders, but again, it lacks the defining feature of persistent, intrusive thoughts central to obsessive-compulsive disorders. Thus, the specific characteristics of obsessive thoughts leading to significant anxiety make the choice of Obsessive-Compulsive or Related Disorders the correct one.