Which disorder is characterized by strong false beliefs despite evidence to the contrary?

The disorder characterized by strong false beliefs despite evidence to the contrary is delusional disorder. This condition specifically features the presence of one or more delusions, which are fixed false beliefs that are resistant to reason or confrontation with actual facts. Individuals with delusional disorder firmly hold onto their beliefs even when convincingly challenged with evidence that contradicts them, which distinguishes it from other mental health issues where reality testing may still be somewhat intact.

In contrast, paranoid schizophrenia involves not only delusions but also encompasses a broader range of symptoms, including hallucinations and disorganized thinking. Generalized anxiety disorder is characterized by excessive anxiety and worry about various aspects of life but does not typically include delusions. Post-traumatic stress disorder is primarily associated with the experience of trauma, leading to symptoms such as flashbacks or severe anxiety, rather than the persistent delusions seen in delusional disorder. Thus, delusional disorder uniquely identifies the central symptom of firmly held false beliefs.