According to DSM-5, which feature must be present for a diagnosis of panic disorder?

1. Panic attacks are sometimes expected, arising with a specific trigger such as being in a tunnel, and sometimes unexpected. 2. For panic disorder the person must experience unexpected attacks, which emerge without an obvious trigger. 3. Diagnosis also requires at least one month of concern about further attacks or self-defeating changes in behaviour. 4. Fear tied to a named object points to specific phobia, and six months of worry points to generalized anxiety disorder. 5. Childhood trauma is a risk factor for several disorders but is not a criterion for panic disorder. _Source: OpenStax Psychology (1st ed., CC BY 4.0), Ch 15 "Psychological Disorders", section 15.4 Anxiety Disorders_