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Clinical Psychology Review Feb 2017Recent decades have seen a surge of research interest in the phenomenon of healthy individuals who experience auditory verbal hallucinations, yet do not exhibit distress... (Review)
Review
Recent decades have seen a surge of research interest in the phenomenon of healthy individuals who experience auditory verbal hallucinations, yet do not exhibit distress or need for care. The aims of the present systematic review are to provide a comprehensive overview of this research and examine how healthy voice-hearers may best be conceptualised in relation to the diagnostic versus 'quasi-' and 'fully-dimensional' continuum models of psychosis. A systematic literature search was conducted, resulting in a total of 398 article titles and abstracts that were scrutinised for appropriateness to the present objective. Seventy articles were identified for full-text analysis, of which 36 met criteria for inclusion. Subjective perceptual experience of voices, such as loudness or location (i.e., inside/outside head), is similar in clinical and non-clinical groups, although clinical voice-hearers have more frequent voices, more negative voice content, and an older age of onset. Groups differ significantly in beliefs about voices, control over voices, voice-related distress, and affective difficulties. Cognitive biases, reduced global functioning, and psychiatric symptoms such as delusions, appear more prevalent in healthy voice-hearers than in healthy controls, yet less than in clinical samples. Transition to mental health difficulties is increased in HVHs, yet only occurs in a minority and is predicted by previous mood problems and voice distress. Whilst healthy voice-hearers show similar brain activity during hallucinatory experiences to clinical voice-hearers, other neuroimaging measures, such as mismatch negativity, have been inconclusive. Risk factors such as familial and childhood trauma appear similar between clinical and non-clinical voice-hearers. Overall the results of the present systematic review support a continuum view rather than a diagnostic model, but cannot distinguish between 'quasi' and 'fully' dimensional models. Healthy voice-hearers may be a key resource in informing transdiagnostic approaches to research of auditory hallucinations.
Topics: Delusions; Hallucinations; Humans; Models, Psychological; Psychotic Disorders
PubMed: 27866082
DOI: 10.1016/j.cpr.2016.10.010 -
Psychiatria Polska 2016The aim of this paper is to review results of studies on the effectiveness of metacognitive training (MCT) for patients with schizophrenia in reduction of psychotic... (Review)
Review
OBJECTIVES
The aim of this paper is to review results of studies on the effectiveness of metacognitive training (MCT) for patients with schizophrenia in reduction of psychotic symptoms and cognitive biases. Furthermore, other variables, like social functioning, insight and neurocognitive functions, are analyzed.
METHODS
Systematic search in databases PubMed, EBSCO, Google Scholar, EMBASE, Cochrane Central Register of Controlled Trials and PsycINFO regarding studies on the effectiveness of the MCT was made. The review included 14 studies published in years 2009-2015, in which design of the study made comparison between MCT group and control group possible.
RESULTS
Combined number of patients in MCT group was 354 and 355 in control group. The largest effect size was obtained for severity of delusions (d < 0.23; 1 >), especially reduction of conviction and distress of delusional beliefs. An effect size regarding negative symptoms reduction was small. Large effect size was observed for insight improvement (d < 0.45; 1.32 >). Positive impact of MCT on cognitive biases severity (d < 0.21; 0.83 >, especially jumping to conclusions) and improvement in some aspects of neurocognitive functions was observed (d < 0.2; 0.63 >). There was no improvement in social functioning of patients in MCT group. Follow-up studies show sustainability in symptoms improvement lasting at least 6 months.
CONCLUSIONS
MCT is an effective form of therapy in reduction of delusions, cognitive biases related to schizophrenia and improvement of insight. Relatively easy accessibility and sustainability of therapeutic effects indicates that MCT can by effectively used in therapy of schizophrenia. To enhance training efficacy, especially in patients' general functioning, combining it with others forms of therapy is to be considered.
Topics: Cognitive Behavioral Therapy; Delusions; Female; Humans; Male; Psychiatric Status Rating Scales; Psychotherapy, Group; Schizophrenia; Schizophrenic Psychology; Severity of Illness Index; Treatment Outcome
PubMed: 27847929
DOI: 10.12740/PP/59113 -
Schizophrenia Bulletin May 2016We did a systematic review and meta-analysis to investigate the magnitude and specificity of the "jumping to conclusions" (JTC) bias in psychosis and delusions. We... (Meta-Analysis)
Meta-Analysis Review
We did a systematic review and meta-analysis to investigate the magnitude and specificity of the "jumping to conclusions" (JTC) bias in psychosis and delusions. We examined the extent to which people with psychosis, and people with delusions specifically, required less information before making decisions. We examined (1) the average amount of information required to make a decision and (2) numbers who demonstrated an extreme JTC bias, as assessed by the "beads task." We compared people with psychosis to people with and without nonpsychotic mental health problems, and people with psychosis with and without delusions. We examined whether reduced data-gathering was associated with increased delusion severity. We identified 55 relevant studies, and acquired previously unpublished data from 16 authors. People with psychosis required significantly less information to make decisions than healthy individuals (k= 33,N= 1935,g= -0.53, 95% CI -0.69, -0.36) and those with nonpsychotic mental health problems (k= 13,N= 667,g= -0.58, 95% CI -0.80, -0.35). The odds of extreme responding in psychosis were between 4 and 6 times higher than the odds of extreme responding by healthy participants and participants with nonpsychotic mental health problems. The JTC bias was linked to a greater probability of delusion occurrence in psychosis (k= 14,N= 770, OR 1.52, 95% CI 1.12, 2.05). There was a trend-level inverse association between data-gathering and delusion severity (k= 18;N= 794;r= -.09, 95% CI -0.21, 0.03). Hence, nonaffective psychosis is characterized by a hasty decision-making style, which is linked to an increased probability of delusions.
Topics: Decision Making; Delusions; Humans; Psychotic Disorders
PubMed: 26519952
DOI: 10.1093/schbul/sbv150 -
Clinical Psychology Review Dec 2015Sleep dysfunction is extremely common in patients with schizophrenia. Recent research indicates that sleep dysfunction may contribute to psychotic experiences such as... (Review)
Review
BACKGROUND
Sleep dysfunction is extremely common in patients with schizophrenia. Recent research indicates that sleep dysfunction may contribute to psychotic experiences such as delusions and hallucinations.
OBJECTIVES
The review aims to evaluate the evidence for a relationship between sleep dysfunction and individual psychotic experiences, make links between the theoretical understanding of each, and highlight areas for future research.
METHOD
A systematic search was conducted to identify studies investigating sleep and psychotic experiences across clinical and non-clinical populations.
RESULTS
66 papers were identified. This literature robustly supports the co-occurrence of sleep dysfunction and psychotic experiences, particularly insomnia with paranoia. Sleep dysfunction predicting subsequent psychotic experiences receives support from epidemiological surveys, research on the transition to psychosis, and relapse studies. There is also evidence that reducing sleep elicits psychotic experiences in non-clinical individuals, and that improving sleep in individuals with psychosis may lessen psychotic experiences. Anxiety and depression consistently arise as (partial) mediators of the sleep and psychosis relationship.
CONCLUSION
Studies are needed that: determine the types of sleep dysfunction linked to individual psychotic experiences; establish a causal connection between sleep and psychotic experiences; and assess treatments for sleep dysfunction in patients with non-affective psychotic disorders such as schizophrenia.
Topics: Delusions; Hallucinations; Humans; Psychotic Disorders; Schizophrenia; Sleep Wake Disorders
PubMed: 26407540
DOI: 10.1016/j.cpr.2015.09.001 -
Schizophrenia Bulletin Nov 2015People with schizophrenia typically experience auditory hallucinations or delusions during acute episodes. Although effective drug treatments are available, many have... (Review)
Review
People with schizophrenia typically experience auditory hallucinations or delusions during acute episodes. Although effective drug treatments are available, many have intractable symptoms that do not recover between acute episodes. One proposed alternative to drug treatments is transcranial magnetic stimulation (TMS). To date, many research trials to assess effectiveness of TMS for people with symptoms of schizophrenia have been conducted worldwide. However, there is a lack of consensus on whether TMS should be recommended to be adopted in routine clinical practice. We conducted a systematic review of the literature for all relevant randomized controlled trials (RCTs) comparing TMS with sham or standard treatment. Forty-one trials (1473 participants) survived eligibility criteria and had extractable data. We found significant differences in favor of temporoparietal TMS compared with sham TMS for global state (7 RCTs, n = 224, MD: -0.5, 95% CI: -0.76 to -0.23) and for positive symptoms measured on the Positive and Negative Syndrome Scale (5 RCTs, n = 127, MD: -6.09, 95% CI: -10.95 to -1.22). However, we also found that the quality of trial reporting was frequently suboptimal and the risks of bias were strong or unascertainable for many trial aspects; this led to many results being graded as very low-quality evidence. On that basis, we were unable to definitively support or refute the routine use of TMS in clinical practice. Future definitive trials of TMS with rigorous processes and high-quality reporting are needed.
Topics: Humans; Randomized Controlled Trials as Topic; Schizophrenia; Transcranial Magnetic Stimulation
PubMed: 26392626
DOI: 10.1093/schbul/sbv121 -
Shanghai Archives of Psychiatry Jun 2015Metacognitive training (MCT) is a novel group psychotherapy method for schizophrenia, but there is, as yet, no conclusive evidence of its efficacy. (Review)
Review
BACKGROUND
Metacognitive training (MCT) is a novel group psychotherapy method for schizophrenia, but there is, as yet, no conclusive evidence of its efficacy.
AIMS
Conduct a meta-analysis to assess the effectiveness of MCT in schizophrenia.
METHODS
Electronic and hand searches were conducted to identify randomized controlled trials about the effects of MCT in schizophrenia that met pre-defined inclusion criteria. The Cochrane Risk of Bias tool was employed to assess of risk of biases, and Cochrane Review Manager version 5.3 and R version 3.1.1 were used to conduct the data synthesis.
RESULTS
Ten trials from 54 unduplicated reports were included in the review, but differences in the methods of assessing outcomes limited the number of studies that could be included in the meta-analysis. Pooling four studies that assessed the positive symptom subscale of the Positive and Negative Syndrome Scale (PANSS) at the end of the trial identified a small but statistically significant greater reduction in the MCT group than in the control group. But pooling four studies that assessed the delusion subscale of the Psychotic Symptom Rating Scales (PSYRATS) at the end of the trial found no significant difference between the groups. Results from the qualitative assessment of the other results that could not be pooled across studies were mixed, some showed a trend in favor of MCT but many found no difference between the groups.
CONCLUSIONS
The limited number of RCT trials, the variability of the method and time of the outcome evaluation, and methodological problems in the trials make it impossible to come to a conclusion about the effectiveness of MCT for schizophrenia. More randomized trials that use standardized outcome measures, that use intention-to-treat (ITT) analyses, and that follow-up participants at regular intervals after the intervention are needed to determine whether or not MCT should become a recommended adjunctive treatment for schizophrenia.
PubMed: 26300597
DOI: 10.11919/j.issn.1002-0829.215065 -
Indian Journal of Psychological Medicine 2015Case reports of delusion of pregnancy have emanated from all over the world, yet the rarity of this phenomenology has precluded systematic large scale descriptive or... (Review)
Review
Case reports of delusion of pregnancy have emanated from all over the world, yet the rarity of this phenomenology has precluded systematic large scale descriptive or cohort studies. This systematic review was conducted to assess the demographic characteristics, clinical profile, treatment outcome and aetiological factors from the published case reports of delusion of pregnancy. Electronic databases including PubMed, PsychInfo and Google Scholar were used to identify case reports relating to delusion of pregnancy published in peer-reviewed English language journals. All such cases were systematically evaluated by investigators, and information was extracted using a structured proforma. A total 40 articles were reviewed which included 84 cases. Demographic characteristics revealed that about half of the patients were aged 20-40 years. The most common diagnoses were schizophrenia (35.7%), bipolar disorders (16.7%) and depression (9.5%). Single foetus was reported by 79.8% of the patients, and 45.2% perceived foetal movements. Good treatment response was noted in 64.3 % of the cases. The prominent aetiological factors that were implicated included psychosocial factors, coenaesthopathological processes, socio-cultural factors and hyperprolactinaemia. Delusion of pregnancy is a heterogeneous symptom which emerges during the course of various neuropsychiatric disorders. A range of aetiopathological mechanisms have been implicated in the causation of this disorder.
PubMed: 25969595
DOI: 10.4103/0253-7176.155609