A dimensional approach in psychiatry strives to identify neurobiological signatures of core (dys)functions such as responses to emotional stimuli across nosological boundaries.

We compared responses to emotional stimuli between major psychiatric disorders and investigated whether there is a psychopathological correlate irrespective of diagnostic group.

We used functional magnetic resonance imaging (fMRI) to assess the functional correlates of responses to unexpected pleasant and aversive emotional pictures in n=175 subjects suffering from alcohol dependence (n=29), schizophrenia (n=37), major depressive disorder (MDD; n=25), bipolar disorder (acute manic episode; n=12), panic disorder (n=12) or attention deficit/hyperactivity disorder (ADHD; n=20) and in healthy controls (n=40). The level of anxiety was measured in all diagnostic groups with the State-Trait Anxiety Inventory, and severity of depressive mood was measured with Beck's depressions inventory in all diagnostic groups with the exception of bipolar patients.

Over all diagnostic groups, a significant activation of BA10 was observed during the presentation of unexpected pleasant pictures, whereas a significant activation of the left amygdala and left insula was found during the presentation of unexpected aversive pictures. We did not find significant effects of group, nor a correlation of neuronal activation with depressed mood or anxiety.

In spite of reported alterations in emotion processing in different psychiatric diseases, responses to emotional pictures did not differ across nosological boundaries in our study. However, a dimensional approach that targets e.g. personality traits or basic learning mechanisms and their neuropsychological correlates across traditional disease categories may be more promising.