How is psychohistory theory of deMause viewed in academia? I've recently came across the psychohistory theory of deMause. To best of my understanding,
it roughly tries to capture the common psychology of an era by analyzing the childbearing practices of that era. See the summary below.

I'd like to know how credible this theory is. Briefly, how is it viewed by academicians, what is the summary of some different opinions surrounding it etc.
The wiki is rather silent on such discussions.
On the subject of criticism and how psychohistory is viewed by academicians, you stated that

The wiki is rather silent on such discussions.

Yet, the Wikipedia article outlines the criticism with plenty of citations.  The criticism in the article is laid out below, although I was not able to find url links for some of the journal articles referenced.

Psychohistory remains a controversial field of study, facing criticism in the academic community (DeMause, 1988; Stannard, 1982; Pomper, 1973; Paul, 1982), with critics referring to it as a pseudoscience (Hunt, 2002). Psychohistory uses a plurality of methodologies, and it is difficult to determine which is appropriate to use in each circumstance.
In 1973, historian Hugh A. Trevor-Roper dismissed the field of psychohistory entirely in response to the publication of Walter Langer’s The Mind of Adolf Hitler. He contended that psychohistory’s methodology rested “on a defective philosophy” and was “vitiated by a defective method.” He also contended that

Instead of proceeding from demonstrable steps, from fact to interpretation, from evidence to conclusion, psycho-historians move in the opposite direction. They deduce their facts from their theories; and this means, in effect, that facts are at the mercy of theory, selected and valued according to their consistence with theory, even invented to support theory (Shepherd, 1978).

DeMause has received criticism on several levels. His formulations have been criticized for being insufficiently supported by credible research (Demos, 1986). He has also received criticism for being a strong proponent of the &quot;black legend&quot; view of childhood history (i.e. that the history of childhood was above all a history of progress, with children being far more often badly mistreated in the past) (Aries, 1975). Similarly, his work has been called a history of child abuse, not childhood (Heywood, 2001). The grim perspective of childhood history is known from other sources, e.g. Edward Shorter's The Making of the Modern Family and Lawrence Stone's The Family, Sex and Marriage in England 1500-1800. However, deMause received criticism for his repeated, detailed descriptions on childhood atrocities:

The reader is doubtless already familiar with examples of these psychohistorical &quot;abuses.&quot; There is a significant difference, however, between the well-meaning and serious, if perhaps simplistic and reductionistic, attempt to understand the psychological in history and the psychohistorical expose that can at times verge on historical pornography. For examples of the more frivolous and distasteful sort of psychohistory, see Journal of Psychohistory. For more serious and scholarly attempts to understand the psychological dimension of the past, see The Psychohistory Review (Kohut, 1986).

Recent psychohistory has also been criticized for being overly-entangled with DeMause, whose theories are not representative of the entire field (Comtois,  2005).
References
Aries, P. (1975). De l'enfant roi a l'enfant martyr. Revue Psychologie. 68, 6.
Comtois, M. (2005) Introduction to Historical Method https://web.archive.org/web/20071130222935/http://cliopolitical.blogspot.com/2005/08/introduction-to-historical_112482482753969170.html
Updated 2010 at http://cliopolitical.blogspot.com/2005/08/introduction-to-historical_112482482753969170.html?m=1
DeMause, L. (1988). On writing childhood history. The Journal of Psychohistory, 16(2), 135. https://search.proquest.com/docview/1305588616
Demos, J. P. (1986). Child Abuse in Context: An Historian's Perspective. In Past, Present and Personal: The Family and The Life Course in American History. NY: Oxford University Press. pp. 68–91.
Heywood, Colin (2001). A History of Childhood. Cambridge: Polity Press. p. 41.
Hunt, L. (2002). Psychology, Pschoanalysis and Historical Thought -The Misfortunes of Psychohistory. In Kramer Lloyd S. and Maza, Sarah C. (ed.). A Companion to Western Historical Thought. Hoboken, NJ: Wiley-Blackwell Publishing. pp. 337–357.
Kohut, Thomas A. (1986). &quot;Psychohistory as History&quot;. The American Historical Review. 91 (2): 336–354. https://doi.org/10.2307/1858137
Paul, R. A. (1982). Review of Lloyd deMause's Foundations of Psychohistory. Journal of Psychoanalytic Anthropology, 5, 469.
Pomper, P. (1973). Problems of a Naturalistic Psychohistory. History and Theory. 12(4): 367–388. https://doi.org/10.2307/2504699
Shepherd, Michael (1978). Clio and Psyche: the lessons of psychohistory. Journal of the Royal Society of Medicine. 71(6): 406–412. https://doi.org/10.1177/014107687807100604
Stannard, D. E. (1982). Shrinking History: On Freud and the Failure of Psychohistory. Oxford University Press, USA.