The effects of growth hormone (GH) deficiency and GH replacement on cognitive performance in adults: A meta-analysis of the current literature

Supplementation of gamma-aminobutyric acid (GABA) affects temporal, but not spatial visual attention

“…In this context it should be acknowledged that cognitive effects of GABA intake might also be mediated by its ability to increase the secretion of growth hormone (GH) from the pituitary gland (Müller, Locatelli, & Cocchi, 1999), which is not protected by the blood-brain barrier. Although evidence of acute effects is limited, GH deficits in patients have been related to impairments in certain cognitive functions (Falleti, Maruff, Burman, & Harris, 2006), suggesting an indirect, alternate route by which orally ingested GABA might act. However, in view of the compatibility with earlier results (Steenbergen et al, 2015a(Steenbergen et al, , 2015b, the present findings do give further credence to the idea that oral ingestion does allow GABA to reach the brain and exert direct effects on cognition, which in the present case were specific to temporal attention.…”

Seeds of neuroendocrine doubt

“…GH is known to have various cognitive effects on the brain and isolated GHD in children can lead to lower IQ, impaired cognition, reduction brain volumes and white matter abnormalities 7,8 . If GHD continued into adulthood (as it usually does) and was untreated then significant cognitive impairments are likely to have persisted 9 .…”

Doping for Chess Performance

“…Furthermore, beneficial effects of the hormone on certain functions, including memory, mental alertness, motivation, and working capacity, have been reported [89]. Falleti [90] evaluated 13 selected studies concerned with the effects of GH deficiency and GH replacement on cognitive performance in adults. In conclusion, this meta-analysis clearly demonstrated that initially present poor cognitive performance can be ameliorated with GH treatment.…”