Evaluating the effect of black myrobalan on cognitive, positive, and negative symptoms in patients with chronic schizophrenia: A randomized, double-blind, placebo-controlled trial.

2021-11-23
Phytotherapy research : PTR 36(1)
- Mohammad Banazadeh
- Mitra Mehrabani
- Nabi Banazadeh
- Fatemeh Dabaghzadeh
- Farzad Shahabi

PubMed: 34814232
DOI: 10.1002/ptr.7340

Study Design

Type: Randomized Controlled Trial (RCT)
Population: patients with chronic schizophrenia
Methods: randomized, double-blind, placebo-controlled clinical trial; participants received six 500 mg capsules of black myrobalan or placebo in two divided doses for 4 weeks
Blinding: Double-blind
Duration: 4 weeks
Funding: Unclear

Schizophrenia, as a chronic and disabling mental disorder, causes a wide range of symptoms, including cognitive impairments, positive, negative, and mood symptoms. There are no effective treatments for cognitive symptoms. Black myrobalan (Terminalia chebula Retz.), a medicinal plant of the Combretaceae family, exerts antioxidant, antiacetylcholinesterase, and anti-inflammatory effects. These effects can lessen the symptoms of schizophrenia. So, this study was conducted to evaluate black myrobalan's impact on cognitive impairments and negative/positive symptoms in patients with chronic schizophrenia. This was a randomized, double-blind, placebo-controlled clinical trial in which participants were divided into treatment and placebo groups. They received six 500 mg capsules of black myrobalan or placebo in two divided doses for 4 weeks. Patients' cognitive impairments, positive, negative, depression/anxiety, and excitement/activity symptoms were assessed using the Screen for Cognitive Impairments in Psychiatry (SCIP) and the relevant subscales of the Positive and Negative Syndrome Scale (PANSS) pretreatment and 4 weeks after treatment. Cognitive impairments (SCIP) (p value .004), negative symptoms (PANSS subscale) (p value .017), and excitement/activity (PANSS subscale) (p value .003) were significantly improved in the black myrobalan group compared with the control group after 4 weeks. No serious adverse effects were reported. Black myrobalan could improve cognitive impairments, negative and excitement/activity symptoms in chronic schizophrenic patients.

Research Insights

Chebulic Myrobalan→Reduced Cognitive Impairment
Cognitive impairments (SCIP) (p value .004), negative symptoms (PANSS subscale) (p value .017), and excitement/activity (PANSS subscale) (p value .003) were significantly improved in the black myrobalan group compared with the control group after 4 weeks.
Effect
Beneficial
Effect size
Small
Dose
3000 mg/day (six 500 mg capsules in two divided doses)
Chebulic Myrobalan→Reduced Depressive Symptom
Patients' cognitive impairments, positive, negative, depression/anxiety, and excitement/activity symptoms were assessed ... Cognitive impairments (SCIP) ... negative symptoms ... and excitement/activity ... were significantly improved ... (no significant effect reported for depression/anxiety symptoms)
Effect
Neutral
Effect size
Small
Dose
3000 mg/day (six 500 mg capsules in two divided doses)
Chebulic Myrobalan→Reduced Hyperactivity
Cognitive impairments (SCIP) (p value .004), negative symptoms (PANSS subscale) (p value .017), and excitement/activity (PANSS subscale) (p value .003) were significantly improved in the black myrobalan group compared with the control group after 4 weeks.
Effect
Beneficial
Effect size
Small
Dose
3000 mg/day (six 500 mg capsules in two divided doses)
Chebulic Myrobalan→Reduced Negative Symptoms
Cognitive impairments (SCIP) (p value .004), negative symptoms (PANSS subscale) (p value .017), and excitement/activity (PANSS subscale) (p value .003) were significantly improved in the black myrobalan group compared with the control group after 4 weeks.
Effect
Beneficial
Effect size
Small
Dose
3000 mg/day (six 500 mg capsules in two divided doses)
Chebulic Myrobalan→Reduced Positive Symptom
Patients' cognitive impairments, positive, negative, depression/anxiety, and excitement/activity symptoms were assessed ... Cognitive impairments (SCIP) ... negative symptoms ... and excitement/activity ... were significantly improved ... (no significant effect reported for positive symptoms)
Effect
Neutral
Effect size
Small
Dose
3000 mg/day (six 500 mg capsules in two divided doses)

Adverse Events Reported

Chebulic Myrobalan→Overall tolerability
No serious adverse effects were reported.
Finding
Reported