Frank Tallis is a clinical psychologist working in London he thinks so .
Here is the link to his article in The Psychologist on this subject.
Apparently he is not the only one Ibn Seena the well known Muslim physician thought so too.
This is what wikipedia says:
Historically, lovesickness has been viewed as a mental illness brought on by the intense changes associated with love. Ibn Sena, a 10th century Muslim physician recognized as an early father of modern medicine, viewed obsession as the principal symptom and cause of love sickness. This diagnosis has been out of favor since the humoral model has been abandoned, and since the advent of modern scientific psychiatry.
It is a bad news for those of us who think that love marriage is the only way to go. If you are sick then how can you make a wise decision . On a personal level I made a wise decision and married love of my life and I am very happy.
When the darkness unfolds... you will find this love sickness always there. To hold your hand, guide you along, show you the world, and sometimes it doesn’t make the love strong.
And you feel that you are their EVERYTHING but NOTHING…….
You spend Hours arguing about who loves who more... ya make phone calls lasting all night long and your heart skip after every word they say... you have a desire to run into their arms and not leave...