Efficacy of Lycium barbarum polysaccharide in adolescents with subthreshold depression: interim analysis of a randomized controlled study

Abstract

Subthreshold depression is a highly prevalent condition in adolescents who are at high risk for developing major depressive disorder. In preclinical models of neurological and psychiatric diseases, Lycium barbarum polysaccharide (LBP) extracted from Goji berries had anti-depressant effects including but not limited to anti-oxidative and anti-inflammatory properties. However, the effect of LBP on subthreshold depression is unclear. To investigate the clinical efficacy and safety of LBP for treating subthreshold depression in adolescents, we conducted a randomized, double-blind, placebo-controlled trial (RCT) with 29 adolescents with subthreshold depression recruited at The Fifth Affiliated Hospital of Guangzhou Medical University. The participants were randomly assigned to groups where they received either 300 mg LBP (LBP group, n = 15, 3 boys and 12 girls aged 15.13 ± 2.17 years) or a placebo (placebo group, n = 14, 2 boys and 12 girls aged 15 ± 1.71 years) for 6 successive weeks. Interim analyses revealed that the LBP group exhibited a greater change in Hamilton Depression Scale (HAMD-24) scores relative to the baseline and a higher remission rate (HAMD-24 total score ≤ 7) at 6 weeks compared with the placebo group. Scores on the Beck Depression Inventory-II (BDI-II), Pittsburgh Sleep Quality Index (PSQI), Kessler Psychological Distress Scale (Kessler), and Screen for Child Anxiety-Related Emotional Disorders (SCARED) were similar between the LBP and placebo groups. No side effects related to the intervention were reported in either group. These results indicate that LBP administration reduced depressive symptoms in adolescents with subthreshold depression. Furthermore, LBP was well tolerated with no treatment-limiting adverse events. Clinical trials involving a larger sample size are needed to further confirm the anti-depressive effects of LBP in adolescents with subthreshold depression. This study was approved by the Medical Ethics Committee of the Fifth Affiliated Hospital of Guangzhou Medical University (Guangzhou, China; approval No. L2019-08) on April 4, 2019 and was registered on ClinicalTrials.gov (identifier: NCT04032795) on July 25, 2019.

Keywords: Goji berry; Lycium barbarum; adolescents; efficacy; polysaccharide; randomized clinical trial; safety; subthreshold depression; tolerance.

Conflict of interest statement

None

Figures

Figure 1

Scheme for group assignment. LBP: Lycium barbarum polysaccharide.

Figure 2

Change in HAMD-24 scores at 0, 4, and 6 weeks in the LBP and placebo groups. The mean HAMD-24 scores in the intervention groups from the baseline assessment to that at 6 weeks. The reduction in HAMD-24 score was greater in the LBP group than in the placebo group at week 6 (P < 0.05). Error bars represent the 95% CI of the mean. CI: Confidence interval; HAMD-24: Hamilton Depression Rating Scale; LBP: Lycium barbarum polysaccharide.

Figure 3

Change in assessment scores from baseline to 6 weeks in the LBP and placebo groups. (A) Factors measured by the HAMD-24. (B) Secondary outcomes. Results are presented as the change (95% CI) in measurement scores based on the estimated marginal mean from the baseline assessment to that at 6 weeks (baseline score minus that at 6 weeks). Error bars represent the 95% CI of the mean. BDI-II: Beck Depression Inventory-II; CI: confidence interval; HAMD-24: Hamilton Depression Rating Scale; Kessler: The Kessler Psychological Distress Scale; PSQI: The Pittsburgh Sleep Quality Index; SCARED: Screen for Child Anxiety-Related Emotional Disorders.