Why do I feel so blue after socialising?

I used to love to leave. I’d scuttle down the street feeling like an escape artist, a mastermind who’d had her fill of fun and was getting closer and closer to bed. But these days, I wonder why I ever have to go. I know that when I stand up and abandon the empty glasses and buttered breadcrumbs on the tablecloth behind me, when I figure out whether the foggy door is push or pull, a horrible sensation is waiting. The chatter will be replaced by silence, the warmth with cold and I’ll feel a ripping up from my belly and through my chest.

It’s not in my nature to sound this dramatic and yet, I’m not lying or exaggerating, I swear. For about a year, maybe more, I’ve been experiencing what I can only call the “post-socialising blues”. I leave an event and a black hole opens within my insides; my blood roars with emptiness and I feel really, really sad. I hate it and I don’t actually understand what’s going on. Especially when up until then, I’d been having fun.

At first, I thought it only happened with friends I don’t see often: those who’ve had babies or moved away, who I love most in the whole world but only get to see once every six months. My sadness made sense then, it was the answer to the question, “When will we be together like this again?”. But then I started experiencing the sensation after meeting up with people I see regularly. If anything, people I see too much.

I wondered, at one point, whether the empty feeling was just a symptom of a bad night. Maybe I didn’t get the intimacy I craved. We spoke at a normal pace, not volleying the conversation back-and-forth breathlessly to say “and-this-and-this-and-this”. We spent way too long talking about that person we both worked with seven years ago, we didn’t crack our chests open, I didn’t get to press my fleshy heart against your fleshy heart; no wonder I felt sad. I’d just spent 2,000 bucks on roasted aubergines and you didn’t even tell me your deepest, darkest fears.

But of course, the sensation arrived even after good nights, the best nights. I considered then if it was anxiety: “Why did I say that stupid thing? Katie was definitely fake laughing! Did Sarah have as much of a good time as I did, or was she counting down the minutes until she could go home to Ben? But.” Another ‘but’, that also wasn’t it. I still experience the sadness after nights where I feel secure, loved and comfortable, when I’m among people who forgive and even love my gaffes. In fact, if anything, I experience it even more.

I’ve finally realised the feeling I feel has nothing to do with the night before it. Whether the party, restaurant meal or dinner party is good or bad, rare or common, I still feel empty afterwards. And the answer, I’m told, may lie in the “hypothalamic circuit underlying the dynamic control of social homeostasis.” In mice.