Over a half of chronic pain (CP) patients present with cognitive complaints, which increase their disability and impact quality of life. The paper reviews objective impairments in memory, attention, processing speed and executive function demonstrated in the CP population. The paper also reviews common pathology underlying cognitive impairment and CP: neuroplasticity in the shared brain areas, neurotransmitter and other molecular mechanisms. Common mechanisms in CP and depression precipitating cognitive impairment are also discussed. The paper also compares the potential of different antidepressants to improve cognitive functions in depression and CP.