Antipsychotic treatment of schizotypy and schizotypal personality disorder: a systematic review

Abstract

Schizotypal personality disorder (SPD) is characterised by thought disorders, experiences of illusions, obsessive ruminations, bizarre or eccentric behaviour, cognitive problems and deficits in social functioning - symptoms that SPD shares with schizophrenia. Efforts have been undertaken to investigate the relationship between these conditions regarding genetics, pathophysiology, and phenomenology. However, treatment of SPD with antipsychotics has received less scientific attention. Embase and PubMed databases were searched using all known generic names of antipsychotics as search terms in combination with the following diagnostic terms: latent schizophrenia, schizotypal disorder, latent type schizophrenia, or SPD. Studies were categorised according to evidence level on the basis of their methodology from A, being the best, to E, being the worst. Five hundred and nine studies were retrieved and scrutinised. Sixteen studies, from the period 1972 to 2012, on antipsychotic treatment of SPD were extracted. Four studies were categorised as evidence level A, two as level B, six as level C and three as level D, with one study level E. Only four randomised, double-blind, placebo-controlled trials, on subjects with well-defined diagnoses, exists. Only amisulpride, risperidone and thiothixene have been studied according to evidence level A. This result warrants further high quality studies of the effects of antipsychotic treatment of SPD.

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): I. Psychosis superspectrum

“…Antipsychotics also treat manic episodes 280 . Moreover, emerging evidence suggests that antipsychotics can reduce psychoticism in patients who do not have frank psychosis 281 . However, antipsychotics are much less efficacious for the detachment spectrum, such as for negative symptoms, and observed benefits may be limited to secondary negative symptoms 282 .…”

Metacognitively oriented psychotherapy for schizotypal personality disorder: A two‐case series

“…A recent systematic review has reported very few eligible studies (randomized control trials, cohort studies, retrospective non‐analytical studies and case studies) on treatment evaluation: 22 studies of the effects of pharmacological treatment and only three on psychotherapy . The studies examining pharmaceutical interventions found low to moderate evidences of the benefit of second‐generation antipsychotics, with most work focusing on risperidone . Among the studies of psychotherapy for SPD, one was a randomized clinical trial (RCT) comparing a form of integrated multifamily psychotherapy (psychoeducation, assertive and social skills training) with treatment as usual; in this study, the integrated therapy arm was less likely to transition to psychosis when compared with treatment as usual.…”

“…Higher degrees of both positive and negative schizotypy have also been correlated with difficulties forming complex and integrated ideas of the self and other and the ability to use that knowledge to respond to psychosocial stressors in a community sample . Schizotypy has been suggested as representing a latent organized set of personality traits, which may be present in a variety of schizophrenia‐related phenotypes, as well as a set of maladaptive traits found among persons in general, which may collapse into a full‐blown PD at the pathological end along the continuum of schizotypy …”

“…8 The studies examining pharmaceutical interventions found low to moderate evidences of the benefit of second-generation antipsychotics, with most work focusing on risperidone. 9 Among the studies of psychotherapy for SPD, one was a randomized clinical trial (RCT) comparing a form of integrated multifamily psychotherapy (psychoeducation, assertive and social skills training) with treatment as usual 10 ; in this study, the integrated therapy arm was less likely to transition to psychosis when compared with treatment as usual. The second study was an uncontrolled clinical trial of psychoeducation and psychodynamic therapy 11 offered to 13 patients with SPD; here, a dropout rate of 38% was noted with no statistically significant improvements in symptoms.…”

“…34 Schizotypy 4 has been suggested as representing a latent organized set of personality traits, which may be present in a variety of schizophrenia-related phenotypes, as well as a set of maladaptive traits found among persons in general, which may collapse into a full-blown PD at the pathological end along the continuum of schizotypy. [2][3][4][5][6][7][8][9][10] In tandem with these studies, research has also suggested that metacognitive-oriented psychotherapies can be useful for persons with schizophrenia as well as several forms of PD including borderline, narcissistic, avoidant and obsessive-compulsive PD. 35,36 These psychotherapies prominently include at least two related variants: metacognitive interpersonal therapy 35,37 (MIT) and metacognitive reflection and insight therapy 18,38 (MERIT).…”