Differential performance on tasks of affective processing and decision-making in patients with Panic Disorder and Panic Disorder with comorbid Major Depressive Disorder

BACKGROUND: Neuropsychological studies have provided evidence for deficits in psychiatric disorders, such as schizophrenia and mood disorders. However, neuropsychological function in Panic Disorder (PD) or PD with a comorbid diagnosis of Major Depressive Disorder (MDD) has not been comprehensively studied. The present study investigated neuropsychological functioning in patients with PD and PD + MDD by focusing on tasks that assess attention, psychomotor speed, executive function, decision-making, and affective processing. METHODS: Twenty-two unmedicated patients with PD, eleven of whom had a secondary diagnosis of MDD, were compared to twenty-two healthy controls, matched for gender, age, and intelligence on tasks of attention, memory, psychomotor speed, executive function, decision-making, and affective processing from the Cambridge Neuropsychological Test Automated Battery (CANTAB), Cambridge Gamble Task, and Affective Go/No-go Task. RESULTS: Relative to matched healthy controls, patients with PD + MDD displayed an attentional bias toward negatively-valenced verbal stimuli (Affective Go/No-go Task) and longer decision-making latencies (Cambridge Gamble Task). Furthermore, the PD + MDD group committed more errors on a task of memory and visual discrimination compared to their controls. In contrast, no group differences were found for PD patients relative to matched control subjects. LIMITATIONS: The sample size was limited, however, all patients were drug-free at the time of testing. CONCLUSIONS: The PD + MDD patients demonstrated deficits on a task involving visual discrimination and working memory, and an attentional bias towards negatively-valenced stimuli. In addition, patients with comorbid depression provided qualitatively different responses in the areas of affective and decision-making processes.