Well - I will say this: many folks with mental disturbances and chemical imbalances have found great relief from parasite cleansing. Most did not parasite cleanse for that specific purpose - but the relief came as a very welcomed surprise!
Now, it will not hurt your brother to parasite cleanse and it might just help relieve some of his symptoms - then again it might not.
Sometimes when a person is toxic - the toxins will travel in the blood and irritate the myelin sheath that covers the brain - this in turn irritates the Central Nervous System. When the CNS kicks in - all sorts of mental disturbances will occur including depression, brain fog, anxiety, panic attacks, chronic fatigue, etc.
If he decides to do the HUAMWORM I would also recommend that he do the Hu-Mana-Tea along with it so the tea can help bind to and remove toxins faster (it will help "coat" the toxins so they won't create more CNS problems).