Chronic pain is a common global problem. 1 It is also a complex problem, as its development is still not fully understood. The literature suggests that several sensory and cognitive factors are involved in the perception of pain. When pain signals persist for a longer period, a peripheral and central sensitization of nociceptive circuits can occur. 2 Consequently, alterations in anatomical brain structure and functioning are observed in patients suffering from chronic pain. 3 This may explain why chronic pain is often associated with various adverse psychological effects like anxiety and depression. 4 Treatment is initially based on non-opioid analgesics like