A PhD is hard. Plenty of people have blogged about mental health problems while doing a PhD e.g.
In some ways I have an advantage as in addition to my Asperger Syndrome diagnosis I have a long history of anxiety and depression going right back to my early teens so am already equipped for dealing with mental health difficulties. Here is what I have found:
There is help available
Imperial College has a Student Counselling and Mental Health Advice Service which can provide counselling and maybe a course of Cognitive Behaviour Therapy (CBT) both of which I have used and found essential for getting through my PhD. CBT has been particularly useful for me as it challenges some of the negative and self-critical thoughts which inevitably creep in when you are working at your highest ability. It does not get rid of such thoughts (indeed, I think a little is needed to keep persevering a difficult academic questions) but does help me manage them. If you have a mental health diagnosis you may also be entitled to Disabled Student Allowance and a specialist mentor who can also help with things such as motivation, organisation and concentration.
Ask for help early
When I had a bout of depression as an undergraduate I waited way too long to let my tutor know I was having difficulties, by then I was so far behind I had to withdraw from university (it worked out ok in the end though as you can see). Now I make sure I let my supervisors know when I’m going through a bad patch and discuss how to manage that – such as which parts of work to prioritise.
Have a plan
Part of my secondary mental health care treatment involved making a Wellness Recovery Action Plan (WRAP). It’s a document that describes how you can keep well, what can trigger a bad patch and what the early warning signs are and ways to help you feel better. I don’t always refer to the paper document these days but just creating one helped me be more aware of how I’m feeling and how to stop myself becoming worse.
It is easy to feel you have to work all the time during a PhD but my supervisors all say that it should be considered as a job and that days off and actual holidays are important. Switch on your out-of-office notifications, take email of your phone and do something other than work for a while. I find this advice hard to take as even when I am not working I am usually thinking about my PhD work or other topics!
Here are some useful links:
Do share any ways you have found to keep mentally healthy at university.