Mental illnesses may be primarily caused by underlying inflammation and inappropriate immune system activation in the brain.

“so often mental illness whether it's depression anxiety bipolar schizophrenia psychotic disorders are thought of as purely derangements of neurotransmitters but there is a large body of evidence a very large body of evidence suggesting that these disorders are much more than neurotransmitter derangements or and that the neurotransmitter derangements in these illnesses are often secondary to an underlying inflammation an underlying inappropriate activation of the immune system in the brain”