Objectives:
The aim of this study was to examine whether obesity affects cognitive functions in people suffering from mental illness.

Methods:
91 persons suffering from mental illness, including 51 women and 40 men took part in the study. Mean age of patients was 46 years. These persons were under constant psychiatric care, they were the participants of the daily support centre. Overweight and obesity was measured by Body Mass Index (BMI). Abdominal obesity was measured according to IDF guidelines and waist-hip ratio (WHR). Cognitive functions were examined using STMS, Verbal Fluency Test and Rey Auditory Verbal Test.

Results:
Abdominal obesity was diagnosed in 70% of patients according to IDF guidelines and in 61% according to WHR, in women these results were respectively: 83% and 94%, while in men 62% and 32%. BMI distribution in the study group was respectively: obesity class II – 5 persons (5%), obesity class I – 26 persons (28%), overweight – 32 persons (35%), correct BMI – 27 persons (30%), underweight – 1 person (2%). There was a negative correlation between WHR, waist circumference and abstract reasoning, direct memory and delayed memory. BMI and body mass correlated negatively only with delayed memory. Number of medications taken by the studied persons showed a positive correlation with body mass and waist circumference. Negative correlations between cognitive functions and body mass, overweight and abdominal obesity was observed in women. In men these correlations were not observed, there were only correlations between cognitive functions and age.

Conclusions:
Obesity contributes to a decline in cognitive functions especially in direct memory and abstract reasoning.