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Blinded by Love: The Neuroscience of Crushes, Obsession and Rejection

Have you ever come down with a case of love sickness? Symptoms may include a constant pining after somebody, a bout of unrequited love and complete and utter takeover of all your thoughts. From a young age, many of us get a ‘crush’ on somebody - and the word itself only half illustrates the intense burden this state of mind can bring. While childhood crushes may come and go each playtime, with age (and lotsa hormones thrown in) these overwhelming sensations become much more intense. You could develop a crush for someone you've known for a while, hardly know at all or have never even met (kissing a celebrity's photo any one?). And if your crush reciprocates your affections, a full-blown state of love blindness can kick in. This transforms your rational perception of the individual you are directing your emotions towards from a normal human into a god/dess-like being. So, it comes as no surprise that if things don’t work out for this romantic relationship, you can be left inconsolable with a lingering obsession for your perceived ‘true love’. And no matter how many times people tell you there are ‘plenty more fish in the sea’, you feel like you caught the most perfect fish but it jumped overboard and got lost at sea. So how does the brain get hooked on one person? And why is it so hard to let go?

It’s just a little crush: Developing a devotion

A crush can hit you out of nowhere. Maybe you only just realised that your friend's cousin has the most beautiful laugh you’ve ever heard, or a complete stranger who made eye contact with you across the office at your new job is going to be your forever love. All of a sudden, this person takes over your day and night dreams and when you are around them, you are overly aware of everything you say and do; making you act totes awks. But how can one person be the fixation of your desires when you have never noticed them in that way before or hardly know them at all?

In neuropsychological terms, a crush is believed to be a person whom you project your own desires onto. Of the little pieces of information you know about this person, you fill in the blanks with all the traits you want from a lover. And neurological sensations support these evidence-devoid judgments. Initial attraction to an individual, normally mediated by looks, scent, a personality trait or general charisma, causes an increased release of dopamine and norepinephrine, while decreasing levels of serotonin. Dopamine is released from the ventral tegmental area into the reward circuitry of the frontal and limbic ('emotional') brain areas, causing feelings of euphoria and giddiness when you are around your crush. Norepinephrine (aka noradrenaline) is synthesised from dopamine and is responsible for keeping the brain and body alert during stressful situations. In terms of your love interest, norepinephrine release leads to increased focus and arousal, as well as a pounding heart, sweaty palms, loss of appetite and sleepless nights. Finally, serotonin, a mood stabilising hormone, decreases in the brain during attraction which promotes obsessive thinking; letting your crush occupy the majority of your thoughts. Together, these chemical shifts create the butterflies in your stomach, overexcitement and constant fantasies when you are crushing hard.

I just can’t get you out of my head: Obsession

So, what happens if your crush from afar becomes an intimate partner? Once you start seeing someone, the same sensations you felt from your initial attractions become even more intense. Any barriers you had up about potential rejection have been dropped and are replaced with trusting feelings, meaning you can really start to let yourself think that this individual will become a permeant fixture of your life. Serotonin levels reduce in initial stages of romantic love to a similar level found in people with obsessive compulsive disorder (OCD). In individuals with OCD, blocking uptake of serotonin is a somewhat affective treatment; suggesting having high levels of serotonin outside neurons prevents OCD-like tendencies. Therefore, low serotonin in early stage romance could promote fixation with your new lover.

As well as chemical changes and activation of brain regions associated with reward, there are specific brain areas which are deactivated in early-stage romantic affairs. This deactivation affects areas such as the amygdala in the temporal lobe and parts of the prefrontal cortex. The amygdala is responsible for fearful emotions and memory, as well as being a key player in the ‘fight or flight’ response whereas the prefrontal cortex plays a pivotal role in judging and critical assessment. Deactivation of these areas associated with ‘negative’ thoughts and feelings is thought to prevent critical judgment of your lover; allowing you to focus on the good and ignore the bad. In addition, the network of brain regions in the frontal, parietal and temporal lobe associated with mentalising, which also allows you to dissociate ‘yourself’ from ‘others’, is also deactivated as love drives the unity of yourself with another. Therefore, your ability to rationalise is somewhat impaired when you are lovestruck, potentially leading you to make some out of character and senseless decisions.

After the love has gone: Rejection

Unfortunately, many crushes do not turn into budding romances. You finally pluck up the courage to ask out your love, but they are just not on the same page as you. Or after initiating a romance, the other person decides to call it quits. And while you try to take the rejection in your stride, internally you have a really tough time dealing with the fact the person who has consumed your thoughts is not going to be your 'one'. Trying to come to terms with this can make you feel down, act irrationally and constantly run over events to try to understand why it didn’t work. These symptoms are similar to those experienced during withdrawal from addictive substances and this is thought to be reflected in brain mechanisms.

A study examined individuals who had been rejected by a partner who they were still in love with using fMRI technology. When these individuals were shown images of their previous partner, activated brain regions included the ventral tegmental area, associated with reward, alongside other areas such as ventral striatum, cingulate gyrus, the insular cortex and the medial and lateral orbitofrontal and prefrontal cortices. The activation of dopaminergic reward centres in these individuals reflect they still feel deep love for those who have rejected them. Some of the other activated areas are similar to those with cocaine addictions associated with ‘craving’ behaviours, thought to be augmented by dopamine release in the striatum, and ‘high’, caused by cingulate stimulation. In addition, activation of the insular cortex reflects the ‘hurtful’ side of rejection as this area is associated with the sensation of physical pain. Together, the brain appears to go through withdrawal symptoms when experiencing rejection from a long-term love and most probably also from a crush or new love. Cerebral activity in rejection mimics that of substance addiction, making you crave your ex-lovers affections, and your brain makes you physically hurt. The concoction of such strong sensations is worthy of a rehab check-in with other addictions, explaining why it is so tough to get through a breakup and to let the idea of your 'perfect relationship' go.




In summary, love is a hard game in which your brain is the true MVP. You quite literally lose your mind over someone by up-regulating 'high' sensations and suppressing those negative feels, making a specific individual your complete focus and seem like the only one for you. If you are currently being crushed by a crush, the best thing to do is to try to take back control of your mind. You can do this by trying to remove this lucky person off the pedestal you have put them on by making them 'human.' If you hardly know this person, the 'perfectness' you are filling into the blanks is more than likely completely wrong. And besides, no one is perfect so it is highly unlikely a single person holds every trait you've ever wanted in a partner. Try to look at this person through someone else's eyes and spot all their really annoying characteristics. This is helpful for you to move forward and also, it is rather therapeutic. You can defeat you crush. After all, love is all in your head.

Materials used to scribe this love letter

Reasons for Crushes

Role of Serotonin in OCD

The neurobiology of love

This is your brain on love

Reward, Addiction, and Emotion Regulation Systems Associated With Rejection in Love

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