He used to be afraid of actors but one day he had an experience with a skeleton and after that he was changed forever. Also in his famous castle there was remains of bodies in the basement with pure evidence of torture. It is evident that Dry. Holmes tortured these young women with no evidence of any remorse. (How Stuff Works). Dry. Holmes himself that he was slowly and slowly turning into the devil since he didn't feel any remorse or anything of such towards his victims (H. H. Holmes; Master of Illusion, chapter 17).
The treatment for antisocial personality disorder Is very tricky but usually most actors use operant conditioning-rewarding the good actions and punishing the Illegal ones-(Notational Library of Medicine). Of course such treatment was not present In the time of Dry. Holmes so he had no way of getting help. Another personality disorder Dry. Holmes had was narcissistic personality disorder. Narcissistic personality disorder is when a person has an inflated self image and inflated goals that he will stop at nothing to achieve them.
This was the case with Midget, as a matter of fact, Herman killed his con-partner in order to perfect a con on an insurance company to get some extra money. H. H. Holmes; Master of Illusion, chapter 3). Having shown that he doesn't really care about his friend or anyone he supposedly had an emotional attachment with, he proved that he has narcissistic personality disorder. This might be caused by his father's beating to him and his abuse. The only way to truly treat that Is through talk therapy so he can try to form deeper connections with people he should be familiar Walt(Notational Library of Medicine).
Again, this kind of treatment wasn't available in the time of Dry. H. H. Holmes so he had no opportunity to seek help. Some people might argue that Dry. Midget had a form of fetishism paraphernalia since he picked out his victims to be young blonde women. Thyrotrophic, or attraction you hair could have been the reason for his choice of victims (Right Diagnosis). The treatments of this include psychoanalysis, hypnosis, behavior therapy, cognitive therapy, drug therapy(Relight Diagnosis). It's very unclear whether he had this disorder or not. All In all Dry. H H Holmes had a lot of personality disorders that led him to become the monster he was.