Whether to quit PhD in psychology: overbearing post-doc, lack of passion for topic, not wanting to enter academia, lack of statistical support I'm over half way into my PhD in psychology and neuroscience in the UK. I think that leaving the programme is the best decision but I'm unsure whether my reasons are good enough. I have gained some valuable experience: computer programming, applying basic mathematics, addressing software and hardware issues etc. 

I approached my supervisor and the director of research 4 months ago about quitting and I was encouraged to continue, but these 4 big issues with the project have persisted, which are sufficient to make me think quitting the programme is the right decision:

1) Before starting, I was not aware how involved the post-doc would be in my project, who is overbearing and has been very difficult to work with from the very beginning. The post-doc is more concerned about being right and getting his own way than being helpful. This hinders my progress because I have to wrestle with what their idea of what my PhD should be. If I had known this, I would not have applied for this PhD. However, I think it's too late to point out this problem and my supervisor would probably think I'm using it as a scapegoat for my own problems.  For now, I'm treating it as a 'training exercise' because you can never choose your colleagues in the real world - but this is a bad reason for staying on with a PhD.

2) My passion for the subject is gone and I have no intention of carrying on in academia afterwards. I don't think my PhD has a use in the real world, so I will definitely be applying for jobs in in the real world. However, if I quit prospective employers will think I'm 'a quitter' and will be put off employing me, but carrying on comes at the expense of experience in the real world, which I think is more valuable.

3) I have found the PhD experience very alienating and I find what I do for a living embarrassing. I'm reluctant to talk to new people because what you do for a living inevitably comes up and I like to avoid talking about it.

4) There is a some mathematics that I have to teach myself (I'm ok with this in principle), with no support from the department, leading to uncertainty as to whether I'm doing it right or whether I'm qualified enough for my position. This combined with reason 1 is slowing down my progress and I'm afraid I won't get enough done and fail the programme.

Do these reasons seem sufficient or should I bite the bullet and carry on?

Thanks.
I agree with you that, regarding 1) - difficult co-workers - you very well might quit and have just as overbearing a boss outside academia.  Although it is difficult, that shouldn't be a key driver in your decision. 
(Note that pride is strongest within academia, so working with people who always think they're right is pretty normal!)

However, reasons #2) &amp; 3) - having no passion because you don't think your work is useful to anyone, and being embarrassed about what you do - are very good reasons to seriously consider changing jobs.  This would probably be true in or out of the academic world.

Reason 4) - the fact that you have to learn something difficult all by yourself - may be pretty normal for many different research fields.  However, the thing that often propels people through these difficulties is a passion for what they're doing, either because it's enjoyable or because it feels like it'll be really useful later (to yourself or others).  If you don't feel either of those, then learning the new topics might be quite painful.

Depending on your situation, another option may exist - assuming you, at some point, were really excited about starting research in this field, perhaps  changing projects (or changing the particular aspect of your project that you pursue) could reinvigorate you?

It should be noted that just about every PhD goes through a time similar to what you're experiencing - the end not in sight, too many hurdles, just want it over, along with the constant fear that you're underperforming.  For me, I realized that at least I could say I loved my daily work, and thought it was really cool.  If I hadn't had that passion for what I was doing I wouldn't have been able to make it through the slump(s).