The literature on the neurobiology of emotional processing in panic disorder (PD) remains inconsistent. Clinical heterogeneity could be causing this.

To investigate differences in brain activity between PD and healthy controls using the emotional faces fMRI paradigm.

To elucidate neurobiological mechanisms underlying emotional processing in PD and previously identified subtypes (Pattyn et al., 2015).

The main analysis compared the neural processing of different emotional facial expressions from a large group of PD patients (n = 73) versus healthy controls (n = 58) originating from the Netherlands Study of Depression and Anxiety (NESDA). A second analysis divided the PD group into the three previously identified subgroups: a cognitive-autonomic (n = 22), an autonomic (n = 16) and an aspecific subgroup (n = 35). The fusiform gyrus, the anterior cingulate cortex and the insula were used in a ROI approach.

Comparing PD patients with healthy controls, a decreased activity on angry faces was observed in the left fusiform gyrus. The subgroup analysis showed more activity in the anterior cingulate cortex on neutral faces in the cognitive-autonomic subgroup versus the autonomic subgroup and a decreased activity in the left fusiform gyrus on angry faces compared to the aspecific subgroup. Less activity was observed in the right insula on neutral faces in the autonomic subgroup versus the aspecific subgroup.

Reduced activity in the left fusiform gyrus was differentiating panic disorder patients from healthy controls. In accordance with clinical subtyping, between-subtype differences are an indication that a phenomenological approach could provide more insight in underlying neurobiological mechanisms in emotional processing in PD.

The authors have not supplied their declaration of competing interest.