Background: Lifetime panic attacks (PAs) have been associated with a range of mental disorders and increased disorder severity. In DSM-5, PAs can be used as a descriptive specifier across disorders. This study investigates frequency and clinical implications of PAs and Fearfull Spells (FS) occurring simultaneously with mental disorders in community youth. Methods: Symptoms and diagnoses of DSM-5 mental disorders including time-related and clinical severity information were assessed from 11/2015–12/2016 in a random sample of 14–21 year olds from Dresden, Germany (N = 1,180). Results: Lifetime prevalence estimates for PAs were highest among participants with lifetime agoraphobia (60.2 %) and separation anxiety disorder (sepAD, 46.0 %). Only 4.8 % of participants with any mental disorder fulfilled the criteria of the DSM-5 PA specifier (simultaneous PAs without a co-occurring panic disorder (PD)), mostly participants with sepAD (12.8 %) and posttraumatic stress disorder (10.7 %). Averaged across all disorders, simultaneous PAs/FSs were associated with lower mental health, higher mental health impairment and more service utilization compared to no PAs/FSs and partly also to lifetime PAs/FSs. Limitations: Retrospective self-report data could be affected by recall bias. Low case numbers limit statistical power. Conclusions: The present findings support the use of PAs/FSs as transdiagnostic DSM-5 specifier, as PAs/FSs occurring simultaneously with mental disorders are descriptively associated with severity indicators. However, the exclusion of PD cases results in a limited proportion of general population youth for which the specifier applies. Larger prospective epidemiological studies could clarify the time course of PAs/FSs, PD and other mental disorders and their effects on severity and course.