Eating disorders, leading to pathological obesity can be related to affective and impulse control disorders. Outcomes of research provided in last years indicate the prefrontal cortex dysfunction to play a significant role in etiology of bipolar affective disorder, regulation of impulsive behaviour as well as regulation of the HPA axis function. The purpose of the research was to verify the hypothesis of co-occurrence of pathological obesity with impairment of working memory and executive function, the latter being a marker of prefrontal cortex dysfunction.

The research included 70 (53 females and 17 males) patients diagnosed with pathological obesity aged 39±11 years and 55 sex, age and education years matched healthy controls.

All subjects performed WCST test where following domains were measured:

1. - perseverative errors (%PE-inability to change the reaction due to ignorance of relevant stimuli)

2. - non-perseverative errors (%NPE-attentional inability to avoid distraction)

3. - completed categories (CC-ability to utilize new information and previous experiences)

4. - conceptual responses (%CONC-ability of conceptual thinking)

5. - set to complete 1st category (1stCAT-ability to formulate a logical conception).

Depression was measured using Hamilton Depression Scale (HAM-D) and Beck Depression Scale.

The study has demonstrated the significant difference between the groups in all domains of WCST. Patients obtained worse results in %PE, %NPE, CC, %CONC and 1stCAT. There was a significant correlation between results in HAM-D and performance on WCST in %PE and %CONC.