My virus by the way was likely coxsackievirus B4 (based on my blood tests and its acute symptoms). Although in the medical literature elevated titers to cytomegalovirus are linked to anxiety, I could not find any known link between coxsackievirus B and anxiety.
However, recently I came across a possible mechanism of
how coxsackievirus B4 may produce anxiety symptoms. This is my own theory of how coxsackievirus B may cause generalized anxiety disorder:
This paper says that:
It has been also proposed that molecular mimicry between protein 2C of coxsackievirus B4 and the autoantigen glutamic acid decarboxylase (GAD65) are playing role in the pathogenesis of insulin-dependent diabetes, which is an autoimmune disease.
So coxsackievirus B4 may trigger an autoimmune attack on the GAD65 enzyme. Now it just so happens that in the brain, GAD65 converts the stimulatory neurotransmitter glutamate into the calming and relaxing neurotransmitter GABA.
Thus if GAD65 is being deactivated because of an autoimmune attack, you will get a build up of glutamate and a shortage of GABA.
Excess glutamate in the amygdala (one of the "anxiety circuits" of the brain) is known to cause anxiety symptoms, and lack of GABA (which is the counterbalancing neurotransmitter to glutamate) will likely further exacerbate these anxiety symptoms.
So this is how a coxsackievirus B4-induced autoimmune attack on GAD65 may lead to generalized anxiety disorder, in my own theory.
Interestingly enough, in diabetes, where autoantibodies to GAD65 may be found, 14% of diabetic patients meet the criteria for generalized anxiety disorder, and 40% of diabetic patients have elevated symptoms of anxiety. Ref:
1
Thus the above GAD65 mechanism might explain why my Coxsackie B4 virus triggered major anxiety symptoms in myself and a few others who caught it. I also think GAD65 autoimmunity may be one of the mechanism by which ME/CFS patients experience anxiety, as coxsackievirus B is a virus frequently found active in ME/CFS patients, and thought to be a major cause of ME/CFS.
My other theory on how viruses may cause generalized anxiety disorder is detailed in
this post (the theory is that chronic microglial activation in the brain is known to release lots of glutamate, and I think in the amygdala this excess glutamate may induce anxiety symptoms).