Landmark compilation of 43 studies reveal 25% of new fathers suffer post natal depression around the 3 to 6 month after birth.http://news.bbc.co.uk/2/hi/health/8687189.stm

How does a father suffer post-natal depression?

It is not biological in the sense of hormonal surges, but they think that lack of sleep, the stress of the newborn and possibly a wife with post-natal depression triggers a similar chemical response in men. I guess kinda like the phantom pregnancies that some men get...

It's "The Lacks" ... lack of sleep, lack of personal time, lack of sex.  Though I, myself, had these lacks, and do at present, I'm not depressed.  Merely annoyed as all get out...

It is a big change and likely most noticeable after the first pregnancy.  I would dispute this has any similarities to phantom pregnancies because this is more about a sudden change in lifestyle that affects the body and therefore has an affect on the psyche.  Phantom pregnancies occur before the birth and are because the father is f(#%ed up.