Decreased glial cell line-derived neurotrophic factor levels in patients with depression: a meta-analytic study.
Glial cell-line derived neurotrophic factor (GDNF) has been shown to promote development, differentiation, and protection of CNS neurons and was thought to play an important role in various neuropsychiatric disorders. Several studies have examined the GDNF levels in patients with depression but shown inconsistent results. In this study, we compared blood GDNF levels between depressive patients and control subjects through meta-analytic method. The effect sizes (ESs) from all eligible studies were synthesized by using a random effect model. In this meta-analysis, we included 526 patients and 502 control subjects from 12 original articles. Compared to control subjects, blood GDNF levels are significantly decreased in patients with depression (ES = -0.62, p = 0.0011). However, significant heterogeneity was found among included studies. Through subgroup analysis, we found that GDNF was still decreased in studies with major depressive disorder (ES = -0.73, p = 0.0001); in studies with non-old-age depression (ES = -1.25, p = 0.0001), but not with old-age depression; and in studies using serum samples (ES = -0.86, p < 0.0001), but not in studies using plasma sample. Meta-regression did not show moderating effects of mean age of subjects, gender distribution, and age of onset of depression. Our findings support blood GDNF levels as a biomarker of depression as a whole, but the results were modulated by psychiatric diagnosis, age of included subjects, and sampling sources. With these results, future studies are required to examine whether effective antidepressant treatment is associated with an increase in serum GDNF levels.
Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital and, Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan. Electronic address: py1029@adm.cgmh.org.tw.
Pao-Yen
PY
Lin
Department of Psychiatry, Tsyr-Huey Mental Hospital, Kaohsiung Jen-Ai's Home, Taiwan.
Ping-Tao
PT
Tseng
D000367:Age Factors; D003865:Major Depressive Disorder / Q000097:blood*; D005260:Female; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000097:blood*; D006801:Humans; D008297:Male; D039781:PubMed / Q000706:statistics & numerical data
D051100:Glial Cell Line-Derived Neurotrophic Factor
Depression; GDNF; Major depression; Meta-analysis