Can a person have schizoid personality disorder and also be manic? He always has  high energy and  he had become interested in a developing a computer program that he believed would make him a millionaire, even though he did not know a lot about computer equipment and software programs. When asked about the computer program, David became very irritable. He accused everyone of not wanting him to be successful. David admitted to not having a girlfriend or any male friends. However, he felt that nothing was really wrong with his behavior.
Degree understand your concerns went through your details. I suggest you not to worry much. Schizoid personality disorder people could show manic behaviors. Preoccupation with fantasy and introspection and facing criticism could trigger mood swings and sometimes manic episodes, in very few cases. But, here, your friend may not be even having schizoid personality disorder. In every possibility, he could be bipolar. Consult a psychiatrist / clinical psychologist for correct diagnosis and start treatment. If you require more of my help in this aspect, Please post a direct question to me in this website. Make sure that you include every minute details possible. I shall prescribe some psychotherapy techniques which should help you cure your condition further. Hope this answers your query. Available for further clarifications. Good luck.