Can one get better from schizoid personality disorder?

May be: By definition, schizoid personality is a disorder that is " idiosyntonic" which means the patient suffering from it is not distressed" and feels somewhat in harmony with the symptoms. One of the biggest motivations for treatment and successful outcome is "being distressed"'by the impact of the symptoms. So in this disorder , there is little motivation because of lack of distress.

Skills Therapy: Yes, improvement is possible - especially if the patient is interested in participating in skills training and has insight into their condition.

Therapy, at best: Schizoids don't believe they suffer from anything, and rarely show up in our consulting rooms because of it. Occasionally they will seek therapy because they are told by a parent, typically, that they need treatment, which is confusing to them for they are perfectly happy to be by themselves the overwhelming majority if the time. In such cases the therapy is more about the person who sent them.

Schizoid: With long-term Psychotherapy, yes.