Mindfulness-based interventions for patients with schizophrenia spectrum disorders: A systematic review of the literature.

BACKGROUND: Mindfulness-based interventions (MBIs) have emerged as secular practices, including elements of mindfulness-based stress reduction (MBSR) and mindfulness-based cognitive therapy (MBCT). While MBIs have been widely adopted for physical and mental illness, only a few available programs are explicitly adapted for psychosis. However, previous reviews have reported the vital heterogeneity regarding treatment program structure. Therefore, this review aims to compare the structure of different mindfulness protocols applied to patients with schizophrenia spectrum disorder (SSD). METHODS: A systematic search was conducted up to March 2023 in PubMed, Embase and PsycInfo. Following our protocol (CRD 42023253356), we followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) checklist. RESULTS: We included 22 randomized controlled trials (RCTs) involving 1500 patients SSD. All programs varied in structure, session components, duration, and instructor experience. While MBSR-like programs focused on stress reactivity, MBCT-like programs addressed primary symptoms of psychosis and relapse prevention. Despite the heterogeneity of programs, some common mechanisms emerged, including attention training, emotion and stress regulation, decentering, self-compassion, and cognitive restructuring. CONCLUSIONS: The critical heterogeneity found limits the interpretation of results. However, most recent trials present fewer risks of bias and more homogenous programs. Findings suggested potential benefits, such as reduced negative symptoms, increased well-being, and decreased hospitalization rates. For future studies, authors should align on more congruent MBIs programs for patients with SSD. Further research is needed to identify optimal mindfulness teaching approaches for patients with psychosis and investigate specific mechanisms of action, relevant processes, and optimal doses in varying settings.

Psilocybin-assisted therapy for depression: A systematic review and dose-response meta-analysis of human studies.

Psilocybin is increasingly studied for its antidepressant effect, but its optimal dosage for depression remains unclear. We conducted a systematic review and a dose-response meta-analysis to find the optimal dosage of psilocybin to reduce depression scores. Following our protocol (CRD 42022220190) multiple electronic databases were searched from their inception until February 2023, to identify double-blind randomized placebo-controlled (RCTs) fixed-dose trials evaluating the use of psilocybin for adult patients with primary or secondary depression. A one-stage dose-response meta-analysis with restricted cubic splines was used. Cochrane risk of bias was used to assess risk of bias. Our analysis included seven studies with a total of 489 participants. Among these, four studies focused on primary depression (N = 366), including one study with patients suffering from treatment-resistant depression. The remaining three studies examined secondary depression (N = 123). The determined 95% effective doses per day (ED95) were 8.92, 24.68, and 36.08 mg/70 kg for patients with secondary depression, primary depression, and both subgroups, respectively. We observed significant dose-response associations for all curves, each plateauing at different levels, except for the bell-shaped curve observed in the case of secondary depression. Additionally, we found significant dose-response associations for various side effects, including physical discomfort, blood pressure increase, nausea/vomiting, headache/migraine, and the risk of prolonged psychosis. In conclusion, we discovered specific ED95 values for different populations, indicating higher ED95 values for treatment-resistant depression, primary depression, and secondary depression groups. Further RCTs are necessary for each population to determine the optimal dosage, allowing for maximum efficacy while minimizing side effects.

Meditation-based mind-body therapies for negative symptoms of schizophrenia: Systematic review of randomized controlled trials and meta-analysis.

Meditation-based mind-body therapies (yoga, tai-chi, qi-gong, mindfulness) have been suggested to have a potential therapeutic effect on negative symptoms. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) examining effectiveness of yoga, tai-chi, qi-gong and mindfulness on negative symptoms of schizophrenia, using different databases and trial registries. The primary outcome was effect of mind-body therapies on negative symptoms and the secondary outcome was effect on positive symptoms. Fifteen RCTs were included in the meta-analysis (N = 1081 patients). Overall, we found a beneficial effect of mind-body interventions on negative symptoms at endpoint compared to treatment-as-usual or non-specific control interventions, but the effect was small and moderate to high heterogeneity was present. A subgroup analysis for different types of therapy revealed a significant effect of mindfulness-based and yoga interventions on negative symptoms, but heterogeneity within the yoga subgroup was high. Our results did not show an increase of positive symptoms (N = 1051). Our results suggest a potential for meditation-based mind-body therapies in the treatment of negative symptoms, in particular for mindfulness based approaches and to a lesser extent yoga. Limitations in the available comparisons do not allow concluding on a specific effect of these interventions. Overall, the currently available evidence remains limited and does not yet allow one to recommend mind-body therapies for the reduction of negative symptoms. However, the present findings justify further research on mind-body therapies for the treatment of negative symptoms.