Is there such a thing like "18-months/half-time syndrome"? I am about 1, 5-2 years in my Ph.D. studies in the no-man's-land between bioinformatics, systems biology and proteomics. (If you are not sure what those terms are, read: "biomedical research")

Coming from a more mathematical/technical background I was thrilled to work in this field, and my M.Sc thesis was pretty successful. Now diving deeper and deeper into the field I feel much less motivated to go on. What frustrates me most, is how little we really understand of complex biological systems, and all our efforts in the field are essentially just waddling in the darkness, trying to find the "holy grail" that may or may not exist. I personally feel that there is an undeniable lack of rigor even amongst the most respectable of scientists out there: 


most biologist really have no clue beyond pipetting liquids left and right, as soon as it comes to data analysis they expect something along the lines of: "computer says yes/no" (see: little Britain's famous sketch)
computer scientists/mathematicians can't really cope with the uncertainties in the data
statisticians are essentially the con-artists of the field, rambling on undecipherable monologues. Sorry if I offend someone but it feels like one can prove/disprove anything with some creative use/interpretation of statistics.  


Putting my rants aside, I went up and talked to one of the younger group leaders in our dept. I feel close enough to the person to give my honest opinion and respect his thoughts on the matter. The first thing he asked me after I was done rambling on, however, was how long it has been since I started. When I told him it's been about a year and a half, he smiled and said: "well, it was about time". According to him, it's common for a Ph.D. candidate to become jaded with his/her work somewhere between 18-months to 2 years in. He claimed that one simply gets deep enough into the field to see all the potential problems/pitfalls in research, and feel negative about it all.

Which brings me to my question(s); is there such a thing as 18-months syndrome, in your experience? Could it be a discipline-dependent phenomenon or applicable to other disciplines? How can one avoid getting stuck in a tailspin (negative spiral)? 

PS: I wanted to tag this question as "research-psychology" but don't have the rep to create a new tag. If someone with more rep agrees with me on the tag, I would appreciate the help :)
Everything is possible: I'm pretty sure, from a large enough population of former PhD students, most will tell you that they felt demotivated at some point, but the timing will depend on the individual and the particular circumstances.

It is true, however, that mid-PhD corresponds to a particularly large number of negative factors, and it is common to feel bad about your thesis around that time. Heck, it's common even that there is a PHD Comics that highlights it:

      

(Don't mind the exaggerated x-axis scale. The area highlighted corresponds to mid-PhD.)

Now, why is that? Well, among your rants, most of the factors are actually listed in your question: Now, you know the field well enough to see not only the good, but also the bad in it. The initial elation has left, and you are left with the doubts. This is sometimes accompanied by deep questioning about your progress: Have I done enough? Have I taken the right course of action? etc.



But the most important point is: how to get out of it? Well, part of the problem is a natural “oscillation”, which means this is probably actually just a low point, a bad moment, and it will actually get better. Don't have too much fear of “spiraling down”: you've made it thus far, and you're aware of the issue!

As for more actionable advice, I would say:


Now that you are more knowledgeable of the field, you can actually start to make better choices: if you don't like a given approach, just steer away from it. You still have some time to do so, and it is part of your PhD to learn making strategic decisions (if you haven't already).
You may not see it, but you will be much more efficient during the second half of your PhD than the first, mostly because you have learnt a lot already and can make better decisions.
Pick a few challenges (one or two) that you would like to meet, and focus on those: you'll feel much better if, instead of chasing some holy grail, you can help solve these specific issues that you care about.
And remember: completing a PhD means becoming an expert in your field, and that actually means being able to critique its practices, recognize the good and the bad. It sounds like you have actually achieved this goal!


I hope this helps…