To the skeptics out there, I too say b******s!
As the captain of a regional jet variant (not the 146) which is prone to cabin air quality incidents, I feel well qualified to report first hand to the armchair critics that I have experienced the effects several times. On the most recent occasion I smelt the familiar 'sock' odour just after takeoff and within seconds developed a moderate headache and the sensations of the 'leans' and being out of touch with my surroundings. The smell stopped once we selected climb thrust and my symptoms cleared soon afterwards although the headache remained for an hour or so. The other pilot smelt the odour but did not notice any effect. Interestingly, no sooner had we released the cabin crew and the No1 (who sits close to the flightdeck) called through to say that she felt ill and dizzy.
There is definately a reluctance to report these incidents. There is always the self doubt aspect - am I being overly sensitive, why is it just me that feels ill?, etc. The effects are so difficult to prove after the event that you feel like a fool when you have to answer to the company and the engineers if you Tech the aircraft with nothing solid to back you up. The smell may not reappear for days afterwards - in my experience these faults are not consistent.
You are also faced with a quandry - on the occasion in question it seemed safer to continue to destination once the problem and symptoms had cleared than to immediately return and attempt a landing whilst feeling the full effects. On the turnaround, the fault did not go 'in the book' because (a) no-one wanted an unscheduled nightstop, (b) there would have been hell to pay and (c) we were convinced by the engineers to do some diagnostics and operate back with the 'suspect' a/c pack off. Sure enough, the problem did not reoccur and the aircraft operated single pack for several days.
Foolishly, I did not tech myself. I felt fine by that stage and as I have a medical to protect there was no way I want any history whatsoever logged against me. The No.1 filled in the requisite forms and was required to have a mandatory period off work and a visit to the doctor. Again, people are reluctant to report because of the rigmarole.