Subtypes
Theodore Millon proposes two subtypes of schizotypal personality. Any individual with schizotypal personality disorder may exhibit either one of the following somewhat different subtypes (Note that Millon believes it is rare for a personality with one pure variant, but rather a mixture of one major variant with one or more secondary variants):

Treatment
Medication
STPD is rarely seen as the primary reason for treatment in a clinical setting, but it often occurs as a comorbid finding with other mental disorders. When patients with STPD are prescribed pharmaceuticals, they are usually prescribed neuroleptics of the sort used to treat schizophrenia; however, the use of neuroleptic drugs in the schizotypal population is in great doubt. While people with schizotypal personality disorder and other attenuated psychotic-spectrum disorders may have a good outcome with neuroleptics in the short term, long-term followup suggests significant impairment in daily functioning compared to schizotypal and even schizophrenic people without neuroleptic drug exposure. Antidepressants are also sometimes prescribed, whether for STPD proper or for comorbid anxiety and depression. Therapy
According to Theodore Millon, schizotypal personality disorder is one of the easiest personality disorders to identify but one of the most difficult to treat with psychotherapy. Persons with STPD usually consider themselves to be simply eccentric or nonconformist; the degree to which they consider their social nonconformity a problem differs from the degree to which it is considered a problem in psychiatry.
Technically speaking, schizotypal personality disorder may also be considered an "extended phenotype" that helps geneticists track the familial or genetic transmission of the genes that are implicated in schizophrenia pathogenesis. But there is also a genetic connection of STPD to mood disorders and depression in particular. Prediction of schizophrenia based on schizotypal traits has a higher accuracy for individuals with high genetic risk for STPD. Social and environmental
Unique environmental factors, which differ from shared sibling experiences, have been found to play a role in the development of STPD and its dimensions. There is now evidence to suggest that parenting styles, early separation, trauma/maltreatment history (especially early childhood neglect) can lead to the development of schizotypal traits. Neglect or abuse, trauma, or family dysfunction during childhood may increase the risk of developing schizotypal personality disorder. There is also evidence indicating insults in the prenatal environment could have an effect on development of STPD. Over time, children learn to interpret social cues and respond appropriately but for unknown reasons this process does not work well for people with this disorder.Schizotypal personality disorders are characterized by a common attentional impairment in various degrees that could serve as a marker of biological susceptibility to STPD. The reason is that an individual who has difficulties taking in information may find it difficult in complicated social situations where interpersonal cues and attentive communications are essential for quality interaction. This might eventually cause the individual to withdraw from most social interactions, thus leading to asociality.