Common anaesthetic could treat diet-induced depression

Researchers have shown that the anaesthetic ketamine, also known as "Special K" and often abused as a recreational drug, could be used to treat depression arising out of chronic overeating and stress.

"The effects of a high-fat diet overlap with those of chronic stress and could also be a contributing factor in depression as well as metabolic disorders such as Type-2 diabetes," said one of the researchers Ronald Duman, professor at Yale University in New Haven, US.

Ketamine reverses depression-like symptoms in rats fed a high-fat diet in a similar way it combats depression and synaptic damage of chronic stress in people, the findings showed.

Ketamine activates the pathway, which regulates the synthesis of proteins involved in creation of connections in the brain that are damaged by stress and depression, the researchers explained.

The pathway is also involved in cellular responses to energy and metabolism, and people with metabolic disorders like Type-2 diabetes are also at higher risk of depression, the study said.

The researchers explored whether diet might influence behaviour of rats fed six times the normal amount of fat. 

They found that after four months of the diet, rats exhibited signs of depression and anxiety.

They also found that a single low dose of ketamine reversed those symptoms quickly, and reversed the disruption of signaling pathways in the brain that were disrupted.

Duman cautioned that the effects of ketamine on metabolism need more research and its proper dosage and use for depression are still a subject of clinical trials.

The study was published in the journal Neuropharmacology.