Schizoid personality disorder
People who have SzPD do not want interpersonal relationships which require emotion and commitment. People with SzPD are introverts who feel the need to be independent or alone. Many schizoids are asexual or have little interest in sexual encounters. Any relationships they may have probably does not involve emotional attachment. SzPD is more common in men than women.  Some of the negative symptoms of the disorder (such as low energy) may be treated with some antipsychotic drugs.