Panic Disorder: Highlights From the Latest Research

An estimated 6 million adults in the United States have panic disorder (PD), which affects women at twice the rate of men. The condition can be severely debilitating and often co-occurs with  depression or substance abuse. Approximately one-third of individuals who experience PD eventually develop agoraphobia. Though early intervention can prevent this progression and effectively treat PD, “people with panic disorder may sometimes go from doctor to doctor for years and visit the emergency room repeatedly before someone correctly diagnoses their condition,” according to the National Institutes of Mental Health.¹ “This is unfortunate, because panic disorder is one of the most treatable of all the anxiety disorders, responding in most cases to certain kinds of medication or certain kinds of cognitive psychotherapy.”

A simple, recently developed tool that could facilitate more accurate diagnosis is the Panic Disorder Screener (PADIS). As reported in Psychiatry Research in July 2015, both the 4-item PADIS and the previously established Patient Health Questionnaire-panic scale (PHQ-panic) were administered to more than 12,000 Australian adults.² A subsample of participants were also interviewed to assess whether they met the criteria for PD according to the DSM-IV. Results show that the PADIS had higher sensitivity (77% vs 57%) than the PHQ-panic for identifying PD, though it had slightly lower specificity (84% vs 91%). “Each one-point increase in PADIS score was associated with 69% increased odds of meeting clinical criteria for panic disorder,” the authors wrote. While high scores on the screener, which is freely available for use by clinicians and researchers, do not constitute a diagnosis of PD, “clinicians could use the PADIS to inform whether an individual might need more thorough assessment of anxiety symptoms, and then whether they might benefit from treatment,” lead developer Philip Batterham, PhD, of the National Institute for Mental Health Research at the Australian National University, told Psychiatry Advisor. “We are also investigating whether the scale can directly inform the intensity of treatment that might be most beneficial to an individual experiencing panic symptoms, through the identification of whether symptoms are mild, moderate, or severe.”

Another study published in 2015, which was co-authored by the US National Institute of Mental Health and researchers in Belgium and the Netherlands, also explored a more tailored approach to PD that may soon inform treatment.³ Based on analysis of a range of anxiety symptoms assessed with the Beck Anxiety Inventory, researchers identified 3 distinct PD subtypes in a mixed-population sample of 658 individuals, each characterized by a different set of symptoms. “No less than 70% of panic disorder patients belonged to a subtype scoring surprisingly low on cognitive-anxious items,” co-author Thomas Pattyn, MD, a psychiatry researcher at the University of Antwerp in Belgium and the Free University of Amsterdam in the Netherlands, told Psychiatry Advisor. “The cognitive-autonomic subtype was the only subtype scoring high on cognitive items such as ‘being scared’ or ‘fear of worst happening.’” Approximately 30% of patients fell into this category, and another 30% could be classified as part of the autonomic subtype; this group had low scores on cognitive items but scored high on autonomous symptoms like “dizziness” and “trembling hands.” The third category, the aspecific subtype, accounted for the remaining 40% of patients. This group did not show specific symptomatology but rather demonstrated the highest scores on general items such as “feeling nervous” and “feeling hot.”

Additionally, the researchers found that severity of PD was correlated with the 3 subtypes. “The more symptoms, the more severe the panic disorder was perceived, and cognitive items were thus mostly found in the most severe subtype,” says Dr Pattyn. Suicide attempts and comorbidity with other disorders were equally common among the autonomic and cognitive-autonomic subtypes but were significantly different in the aspecific subtype. Further research is needed before concrete treatment implications can be advised, but “it seems logical that different symptoms, possibly originating from different neurobiological mechanisms, could benefit from different kinds of treatments.”