drspouse there is a term "adjustment disorder" that covers these types of things:
"Adjustment Disorder
A recent and possibly even expected event has an excessively negative effect. Adjustment disorder is marked by anxiety, reckless behavior, and difficulty in "getting over it."
Definition
Adjustment disorder is an abnormal and excessive reaction to an identifiable life stressor. The reaction is more severe than would normally be expected and can result in significant impairment in social, occupational, or academic functioning. Symptoms must arise within three months of the onset of the stressor and last no longer than six months after the stressor has ended.
The response may be linked to a single event (a flood or fire, marriage, divorce, starting school, a new job) or multiple events (marital problems or severe business difficulties). Stressors may be recurrent events (a child witnessing parents constantly fighting, chemotherapy, financial difficulties) or continuous (living in a crime-ridden neighborhood).
Adjustment disorder often occurs with one or more of the following: depressed mood, anxiety, disturbance of conduct (in which the patient violates rights of others or major age-appropriate societal norms or rules), and maladaptive reactions (i.e. problems related to work or school, physical complaints, social isolation).
Adjustment disorders are associated with high risk of suicide and suicidal behavior, substance abuse, and the prolongation of other medical disorders or interference with their treatment. Adjustment disorder that persists may progress to become a more severe mental disorder, such as major depressive disorder.
Adjustment disorder is sometimes referred to as Situational Depression."
Clearly having a new baby in the family is a huge change, as is adoption. I wonder if others past the partner could be affected - a sibling, grandparent etc.
I don't think it will serve women well to take peri natal depression and say "it happens to men too" (which it does) - as in a society where men are taken more seriosuly than women, it will simply suck resource from the already scant maternity services, and take attention off something that hasn't been recognised for that long in the first place.
I found that ante natal depression has only been recognised in the last 20 years or so - before that it was assumed that women would glow and be marvellous in pregnancy (for reasons most of us on FWR will be able to think of quite easily!) - to generalise it across a much larger group before it's even recognised as a "thing" for women, will not do women any good I think.
In terms of research as well, if the pregnancy and birth / post birth related MHPs that women suffer, are deemded as the same as men, then any mechanisms related to the pregnancy, birth, post birth are automatically discounted. As, men can't be suffering them. Saying that they are the same as a starting point, rules out from the get go the possibility that they are not. And that for some women, there may be a physiological component. So we will never be able to address it.
Women are always deemed to be at the mercy of our hormones, and irraltional, weak minded etc. It seems odd to entirely rule it out any physiological causes / contributors (does anything else happen to the brain when pg? I am no expert) on the basis that men get it too so it must be the same.