Wouldn’t this be excuses RA’s defense should’ve been presenting to the court if they had any merit? As the D didn’t, neither disclosure nor medications were a suspected cause for his confessions. (Of note, only mention of anything significant preceding his confessions was he had found religion.) The D blamed the confessions on his incarceration and suggested it should be considered coercion by the state. The Judge disagreed and ruled the confessions are in.
“The statements given by the defendant were unsolicited by any of the individuals and were voluntarily given without coercion or interrogation," Special Judge Fran Gull wrote in the ruling. "The evidence shows he specifically sought out the Warden by written communication he initiated, and verbal statements he offered to the guards, inmates, mental health professionals, and medical personnel."Judge rules accused Delphi killer Richard Allen's alleged confessions can be used as trial evidence
A judge ruled multiple confessions that Richard Allen allegedly made in the murders of Abby Williams and Libby German in 2017 can be used as evidence at trial.abc7chicago.com
I think you've nailed the issue.
The factors like psychosis etc go to the weight the jury will ultimately give these confessions, but they don't make the confessions involuntary - and I guess that is why the D did not appear to make that argument.
Just as a question of common sense, I think you are going to struggle with the idea confessions to wife/mum/doctor are 'involuntary' - even in a context of incarceration.
MOO