Schizophrenia, Mice, and Procreation – A Halachic Analysis


(By Rabbi Yair Hoffman for

There is a fascinating question raised in Chasuchei Chemed of Rav Yitzchok Zilberstein in Brachos (10a).  A husband found out that the genetic predisposition toward schizophrenia in his future children was five times higher than that of the general populace.  This was on account of his wife’s family history of that illness.  He decided that he did not have the tools to deal with such an issue and refused to have children.  Rav Zilberstein posed the question to his father-in-law, Rav ELyashiv zt”l.


From a halachic perspective, there are two obligations in having children.  There is the Mitzvah of pru ur’vu, being fruitful and multiplying.  One fulfills this basic obligation by having a son and a daughter.  There is, however, yet another – second obligation in having children.  This second obligation is called, “uba’erev lo sanach yadecha” (Koheles 11:6) and it is discussed in tractate Yevamos (62b.)  This obligation is to continue having children beyond the basic Mitzvah of just two children – a boy and a girl.

The idea is best expressed in the words of Yishayahu (45:18) : “He did not create [the world] for a waste, He formed it to be inhabited.”

In the words of Rabbi Yehoshua in that Gemorah, “If one had children when he was young, he should continue to have children when he is old. As the verse (Koheles 11:6) states: ‘In the morning, sow your seed, and in the evening, do not withhold your hand, for you know not which will succeed, this one or that one, or whether both of them will be equally good.’”


As far as obligation number one, most authorities state that one should still have children even with the risk of a mental illness.  As far as obligation number two goes, a number of years ago, this author posed the question to the author of the Tzitz Eliezer, Rav Eliezer Yehudah Waldenberg zt”l.  He ruled that there is no second obligation when it involves bringing sick children into the world.  Presumably, this may be a controversial ruling.


Schizophrenia affects about 1% of the world’s population.  If we think about it, that means that in the United States alone, there are some 3.7 million Americans walking around with this disorder.   So it is not just that peculiar great uncle or great aunt that some families have that are never really discussed by parents.  There are a number of other people too.  In a typical Yeshiva of 300 kids or more, three of them will statistically suffer from the illness, rachmana litzlan.

Schizophrenia, of course, is a mental disorder that is characterized by disorganized thoughts, false beliefs, difficult social relationships, and paranoid delusional thoughts among others.  There is also a tendency to not care about social relationships, and to send away all friends and relatives.   Schizophrenics can often have complex delusional theories, often talk to themselves, stop working, and can seriously affect the well-being of others around them.  It is, thus, quite understandable that the husband, discussed in Rav Zilbershtein’s Sefer above, did not wish to bring others into the world who suffer from the disease.


It is known that, generally speaking, schizophrenia breaks out at young adulthood, although there are pre-dispositional processes that occur beforehand.

It is a sad reality that many of the people who suffer from this devastating psychiatric disorder do not seek treatment for it.


Recently, there has seeningly been a breakthrough in how schizophrenia can be prevented, which can possibly affect how halachic authorities view this condition.  The research is a possible game-changer for those who can suffer from this illness.  In this author’s opinion, the research is almost at the level of insulin for Type One diabetics – which was once a veritable death sentence.

Using schizophrenic mice, researchers from the Caroni group at the Friedrich Miescher Institute for Biomedical Research (FMI) have demonstrated that, like humans, the characteristic network and cognitive deficits of schizophrenia only emerge in adult mice. They, have also demonstrated that these deficits could possibly be permanently prevented by specific treatments during a specific late adolescence time window. Their study has been published in Cell in an article entitled “Long-Lasting Rescue of Network and Cognitive Dysfunction in a Genetic Schizophrenia Model.”

Generally speaking, treatment for schizophrenia has focused more on the symptoms than the causes and pretty much various cpcktails of antipsychotic medications.


There are a multiplicity of contributing factors toward schizophrenia including problems during birth, stress, psycho-social factors, familial pre-disposition toward it, and the use of marijuana during adolescence.   There are also people with something called “22Q11DS syndrome” characterized by deletions within a segment of chromosome 22.  These people have a 20 to 30 times increased risk of developing schizophrenia. The schizophrenic mice used in the study were breeded with a deletion in their corresponding chromosome 22.

The researchers tried suppressing the network dysfunctions of the mice during the most critical time window. They applied repeated treatments targeting the hippocampal PV network with common antipsychotic drugs or with more specific genetic activators of PV neurons, during the 6-10 days, that characterize the transitional period between late adolescence and adulthood in mice.

“Our findings in a genetic mouse model support the hypothesis that a critical developmental time window influences the emergence of schizophrenia at the transition between late adolescence and adulthood – and that it is possible to prevent the progression of schizophrenia by treatment during that time window,” remarked Pico Caroni. “It might be possible to build on our study to develop therapeutic strategies to prevent the outbreak of schizophrenia in at risk individuals.”


This author would like to suggest that this research, if it proves to be correct, can directly affect Rav Waldenberg’s ruling here.  There is a very good chance that the research discussed here can effectively sop schizophrenia by the time any child reaches adolescence.  Indeed, since the drugs are already legal, doctors could feasibly prescribe them to during the period of adolescence.

And while the breakthrough does not help those who already suffer from the disease, it can truly help for those who are at grave risk of developing it.  May Hashem provide a refuah shleimah for all those that are suffering illness. Amain.

The author can be reached at [email protected]


  1. That is indeed on Berachos 10a, as mentioned in the article. I believe that the point of the Tzitz Eliezer is exactly this – that one may not make such calculations for “obligation number one:.

  2. requiring to take medication is itself a risk that must be considered. all such sheailot require an individual pesak given unique circumstances likely involved. a blog post can raise issues, not pasken sheailot.

  3. 1. Correlation is not causation. The goyim’s science in this area should be “taken with a grain of salt”. It should be noted that much of the discussion of behavior in the area of mental illness is cultural in nature and research done by and for goyim may be inapplicable to yidden (e.g. goyim assum it is normal for a man to want to work at a job, we consdier it normal for a man to be a scholar.

    2. Don’t marry a crazy rodent.