Department of Psychiatry, Bezmialem Vakif University, Istanbul, Turkey.
Department of Biochemistry, Bezmialem Vakif University, Istanbul, Turkey.
Metab Brain Dis. 2019 Jun;34(3):865-874. doi: 10.1007/s11011-019-00395-3. Epub 2019 Feb 13.
Melatonin, a neuro-differentiation factor, may play a role in the neurodevelopmental origins of schizophrenia. Cognitive impairment and decreased melatonin are reported in schizophrenia; however, the relationship between them remains unclear. We hypothesised that patients with schizophrenia would have lower concentrations of circulating melatonin than healthy controls and that melatonin levels would be associated with cognitive impairment. This study included 47 patients with schizophrenia and 40 healthy controls (HC). Serum melatonin concentrations were measured using the enzyme-linked immunosorbent assay. Positive and Negative Syndrome Scales (PANSS), The Morningness-Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality Index (PSQI), the Stroop and Oktem verbal memory processes (VMPT) tests were applied. Patients with schizophrenia had lower levels of melatonin compared to the HC group (p = 0.016), also after controlling for age, sex, and body mass index (BMI) (p = 0.024). In patients with schizophrenia, melatonin concentrations were associated with higher BMI (rho = 0.34, p = 0.01) and lower MEQ score (rho = -0.29, p = 0.035). The patient sample was split into low and high melatonin categories by using the median melatonin concentration in HC as the cut-off. Patients in the low melatonin group had poorer performance in VMPT-Recognition (p = 0.026) and Stroop-Colour Error (p = 0.032). Notwithstanding its limitations, the findings of this exploratory study suggest that decreased serum melatonin concentrations observed in schizophrenia might also be associated with cognitive impairment and circadian preferences. Future studies are required to investigate the role of melatonergic pathways in patients with schizophrenia.
褪黑素是一种神经分化因子，可能在精神分裂症的神经发育起源中发挥作用。有研究报道精神分裂症患者存在认知损伤和褪黑素水平降低，但两者之间的关系尚不清楚。我们假设精神分裂症患者的循环褪黑素浓度低于健康对照组，且褪黑素水平与认知损伤有关。本研究纳入了 47 名精神分裂症患者和 40 名健康对照者（HC）。采用酶联免疫吸附试验检测血清褪黑素浓度。应用阳性和阴性综合征量表（PANSS）、早晨-晚间问卷（MEQ）、匹兹堡睡眠质量指数（PSQI）、Stroop 和 Oktem 言语记忆过程（VMPT）测试。与 HC 组相比，精神分裂症患者的褪黑素水平较低（p=0.016），即使在校正了年龄、性别和体重指数（BMI）后（p=0.024）。在精神分裂症患者中，褪黑素浓度与更高的 BMI（rho=0.34，p=0.01）和更低的 MEQ 评分（rho=-0.29，p=0.035）相关。通过以 HC 组中的中位数褪黑素浓度作为截止值，将患者样本分为低和高褪黑素组。低褪黑素组患者在 VMPT-识别（p=0.026）和 Stroop-颜色错误（p=0.032）方面的表现更差。尽管本研究存在局限性，但这些发现提示，在精神分裂症中观察到的血清褪黑素浓度降低可能也与认知损伤和昼夜节律偏好有关。需要进一步的研究来探讨精神分裂症患者中褪黑素能通路的作用。
