Can my symptoms erase my memories?

I am the woman you want on your trivia team. I have an obsessive memory for facts. I thrive at work because I can draw on obscure documents I read four years ago.

I remember the birthdays and phone numbers of people I went to primary school with. I learn things quickly. I rarely get lost because I can look at a map and it imprints on my mind.

But about ten years ago I noticed something.

While my brain is excellent at remembering single facts, numbers or places, I have almost no long term 'memories'. My brain works like an etch-a-sketch, constantly erasing memories from more than a few years ago.

At secondary school, I realised I could barely remember my primary years. At university, I struggled to recall my school days. Now, as an adult I struggle to remember my move to Australia and my first years working here.

For a long time, it's been hard to know if that's odd or not. Memories are one of those intangible things, it's impossible to genuinely know how other people experience them. TV and films portray memories as crystal clear videos replaying in your mind. I don't get that, but I don't even get vague suggestions of moments, people, or experiences. I look back and all I see is fog. Photos or others' anecdotes leave me blank.

So yes, I thought I was weird.

In April, when I was on holiday in the UK, my friend invited me to a psychology seminar (yes, I am that kind of person who goes to psychology seminars on holiday).

The presentation was by Professor Anke Ehlers, Co-Director at the Oxford Centre for Anxiety Disorders and Trauma. She specialises in psychological treatments for post-traumatic stress disorder (PTSD), and has done some fascinating work to uncover the mechanisms that cause distress and traumatic memories.

One of the central mechanisms she discussed was a lack of memory, specificity, that people with PTSD generalise their non-traumatic memories. Hearing this made me jump.

This was me. My fog.

I can tell people what I was doing at a point in time – which year I went on holiday to the USA – but I would struggle to tell you what I saw and most importantly, how it made me feel. Despite this, I will be jolted back into vivid memories (positive, but mainly negative – anxiety or anger) by something I can't explain, usually a sound or a smell. But, when the trigger passes, the memory vanishes.

As I rushed to tell my friend about my exciting discovery, she (who holds a psychology qualification) informed me that this phenomenon was well-established for people with depression. Indeed, recent evidence suggests that depression damages the part of the brain responsible for memories.

'I look at you, and I… and I'm home. Please… I don't want that to go away. I don't want to forget.'

– Dory, from Finding Nemo.

Memories are not just past events, they're my past experiences. They influence how I feel and they shape my future interactions with the world. My memories shape who I am and who I will be. Not holding them can make me feel lost.

Honestly, my lack of memory has always frightened me a little. Learning that I am not alone has provided me with an immense sense of reassurance.

When you experience mental ill-health, you need a solid ground and memories can contribute to that. It's one of the reasons I very intentionally take and share photos. I want to remember where I've been and the experiences that make me, me. I'm not worried about tomorrow, but I am worried about the future, years down the track when I realise the etch-a-sketch has been reset.

Joanna lives with depression and anxiety, and works in the mental health sector. This piece was originally published in Joanna's blog.