It must be love, love, love

In the brain, romantic love shows similarities to going mildly insane or suffering from obsessive compulsive disorder. Studies show that when you first fall in love, serotonin levels plummet and the brain's reward centres are flooded with dopamine. This gives a high similar to an addictive drug, creating powerful links in our minds between pleasure and the object of our affection, and meaning we crave the hit of our beloved again and again.

The four stages of love

• Lust -  driven by the sex hormones testosterone and oestrogen.
• Attraction - In the attraction stage, a group of neuro-transmitters called 'monoamines' play an important role:
• Dopamine - the same chemical activated by cocaine and nicotine
• Norepinephrine (adrenaline) - Starts us sweating and gets the heart racing.
• Serotonin
• Attachment - 
• Oxytocin - released by the hypothalamus gland during child birth and also helps the breast express milk. It helps cement the strong bond between mother and child. It is also released by both sexes during intimate activities.
• Vasopressin

Happy valentines