On this page I found two definition of mental health.
http://www.medicalnewstoday.com/articles/154543.php
According to Medilexicon's medical dictionary, mental health is "emotional, behavioral, and social maturity or normality; the absence of a mental or behavioral disorder; a state of psychological well-being in which one has achieved a satisfactory integration of one's instinctual drives acceptable to both oneself and one's social milieu; an appropriate balance of love, work, and leisure pursuits".
According to WHO (World Health Organization), mental health is "a state of well-being in which the individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to his or her community".
There is a big difference between the two definitions. The first one can be well applied to hypoanimalistic individuals, who want the homeostasis of their personal needs to the limit of not taking advantage of others, based on a fair exchange of giving and receiving. (more in entry 93. Identity and Needs)
The second definition claims, that mental health means to be a particle. "is able to make a contribution to his or her community" is a clear description of having a purpose for others beyond a fair exchange.
I seriously doubt, that submitting to the urge of having a purpose is beneficial for the mental health, because it creates recurrent and permanent serious conflicts between different needs.
A simple analogy: An addict with a limited amount of money in his pocket and a brain capable of some foresight knows, that if he gives in to his need to eat, he will later suffer from withdrawal syndrome. So refraining from giving in to the hunger the stronger need of the addiction can be satisfied.
It is similar with breeders. The caretaker of a baby might feel a need to read a book, go for a hike or to a museum, or simply just sleep, but there is this screaming bundle of her genes with the stinking napkins to be changed. If she does not do it, then she gets punished for neglect, and since one major reason for sacrifices is the afterworld, she also feels failing her duties to her deity. So she sacrifices her real personal needs and changes the napkins.
Both are principally the same situation. The person got himself addicted by his own doing, the woman decided to become a breeder by her own doing.
Particles and especially breeders get themselves stuck in very unhealthy situations, without a way out. A woman, depending financially on a husband, who is absent most of the day, who cheats on her and mistreats her, has been coerced by her instincts and brainwashed by her religion to put her children above her own wellbeing. When such a situation destroys her mental health, the rational way for her to restore it would be to dump her brats on the husband, whose they are as much as hers, get her freedom and leave. But she does not do it, because she does not allow herself to see, how much her situation is unhealthy and her reaction of suffering is logical. Instead she takes pills, goes to therapy and does everything possible to get herself deformed until she functions with a kind of artificial pseudo-mental-health waiting for the reward after her death.
Being the slave of brats 24 hours a day and 7 days a week is a serious mental health risk for many people. If society and the government as the representatives of the species insist on the survival by having enough progeny, this should not be achieved by brainwashing particles into self-sacrifice. Parents should be given enough respite to preserve their mental health. Just as schools are free, so should be enough baby-sitting hours and there should be places like camps or homes, where people have a right to deposit their children for at least one weekend per month to recover from them.
Breeding is a risk to mental health not only for the mothers, but also for the men, who have to work hard under the condition of stress and sometimes unhealthy work conditions to earn enough money to provide for an entire family. When women work part-time to fulfill their need of being more than a cleaner and cook for their brats, this only adds to their stress.
To preserve the mental health of the breeding couple, they both need a reduction of stress. Society needs to supply them both with part-time jobs, so that they together with two part-time jobs have enough money to live on, and they can give each other enough respite to not being slaves to neither job nor brats 24 hours a day.
Breeding is an unacknowledged major risk to mental health.