Rolf Furili was a lecturer in Semtic languages, at Oslo University and is a Jehovah's Witness, so this entire study is highly questionable. His chief claim to fame prior to this was defending the Watchtower's questionable fall of Babylon chronology, he is not an expert in the field of mental illness and he has an obvious bias. This is a shameful attempt by the Watchtower to hide their problem with Mental illness and suicide, they have shown in the past that they will use dishonest methods like this to prop up their beliefs.
From / Wikipedia
Furuli has attempted to defend the religious views of Jehovah's Witnessesโof which Furuli is a member[3]โincluding their view that Jerusalem was destroyed by theBabylonians in 607 BC rather than the broadly recognised dating of its destruction in 587 BC.[4]
Also from Wikipedia
In a 2004 issue of Journal for the Study of the Old Testament, Lester L. Grabbe, professor of theology at the University of Hull, said of Furuli's study: "Once again we have an amateur who wants to rewrite scholarship. ... F. shows little evidence of having put his theories to the test with specialists in Mesopotamian astronomy and Persian history."[5]