"My Big Black Dog". Sounds like the title of an essay a primary school kid would write about his pet for his English homework.

I grew up in Uganda in the 90s, and we really didn't know what a pet was. Some friends and neighbors had dogs, cats, but I don't remember ever hearing anyone describe them as “a pet”.

My memories of dogs mostly consist of chained ones fiercely barking at me. I can still see some of those dogs' faces, looking at me through the kennel door like I was a juicy steak. You didn't want to be outdoors after dark, because most of those dogs would be unleashed from the chains and out of the kennels.

When I came to Japan, I got to know what a "pet" was. I saw people walking their dogs, people carrying cats in baskets/boxes, I saw clothed dogs, I saw pet barber shops. In the super markets I saw long aisles of pet food, saw fat dogs that I was thinking to myself, I could beat this one in a foot race.

Some of you might think of dogs the way I used to. Or, you know dogs as pets, and could even have one. To me though, dog = scary. Even now as an adult, though I say I don't fear them anymore, should it charge at me barking, I don't trust myself to stand my ground and not flee.

The dog I want to talk about today, my dog, it's not the fierce barking and growling kind like the ones that terrified me growing up. Neither is it a pet. This is another kind, arguably worse than any I'd ever seen.

This black dog, it doesn't bite your calf, it doesn't bark loud so the whole neighborhood can hear it. It doesn't mean it's harmless, though. It's quite capable of a lot of harm. It devours one silently, in places where no one else sees. The "black dog", depression.

It's 2017, most of you must have heard of it. Some of you might have it, or had it at some point. Perhaps you don't know what exactly it is. Many who have it suffer silently. Partly because of the fear that no one will understand. Also, there's a lot of misconceptions about what depression is, and a lot of stigma. Some have had it torment them, and they don't know what really is causing their misery.

For starters, depression is not sadness, as it's often misconceived. It's also not laziness.

For me, I've come to think of it as a life sucking darkness, like a black hole. It kills you a little every day, chipping away at the core of one's being. It's crippling and numbing at the same time.

Although one might feel some sadness, a lot of the time there's a lot of nothingness. Then the rest is a nasty cocktail of all the negative emotions you can think of. Anger, guilt, sadness, anxiety, hopelessness, self-loathing, loneliness…

Today, I don't want to focus on what it is. I'm yet to grasp that myself. How to fight it, beat it, what causes it… all that will be talk for another day. Today, I want to open the conversation, I want us to start talking about it. The black dog, commonly known as depression is real. We have to illuminate it, bring it out in the light and fight it together.

Hi, I'm Jonathan. I have a black dog, its name is depression.

If you too have the dog, don't be afraid, don't be ashamed. Raise your hand and let's get talking. If you know someone who does, be supportive. If you don't understand, ask. Remember, it's not sadness, we don't need cheering up.

In the video below, writer and illustrator Matthew Johnstone tells his story of overcoming the "black dog of depression".I had a black dog, his name was depression