This natural drug creates an euphoric high and helps obscure the failings and shortcomings of the potential mate. Such oblivion - perceiving only the spouse's good sides while discarding her bad ones - is a pathology akin to the primitive psychological defense mechanism known as "splitting". Narcissists - patients suffering from the Narcissistic Personality Disorder - also Idealize romantic or intimate partners. A similar cognitive-emotional impairment is common in many mental health conditions.
Pretty provocative stuff!!
The activity of a host of neurotransmitters - such as Dopamine, Adrenaline (Norepinephrine), and Serotonin - is heightened (or in the case of Serotonin, lowered) in both paramours. Yet, such irregularities are also associated with Obsessive-Compulsive Disorder (OCD) and depression.
It is telling that once attachment is formed and infatuation gives way to a more stable and less exuberant relationship, the levels of these substances return to normal. They are replaced by two hormones (endorphins) which usually play a part in social interactions (including bonding and sex): Oxytocin (the "cuddling chemical") and Vasopressin. Oxytocin facilitates bonding.