headache, cognitive problems

HI
I am concerned about my 38 year old brother who has had a permanent headache for approximately 2 months. The headache is always there but fluctuates from moderate to very severe in terms of pain.
Associated with this is a general cognitive decline- very confused thinking, difficulties with formulating thoughts for writing, severe short term memory problems, poor organisation of acitvities and difficulties with attention and concentration. At times there is also confused behaviour but this is less common.
Sleep is also an big issue varying from being unable to sleep at all to sleeping maybe 18-20 hours per day.
Pertinent history would include:
Tested high for cholestorol about 4 months ago but recent dietary changes and statins have brought this down to a very low level. (he recently decided to stop the statins as he felt they made his cognitive symptoms worse) BP also high around this time but now testing in the normal range.
Weight within the normal range.
Physically fit- walks about 6 miles per day.
Recently left a very stressful and emotional job.
Past 3 years have been very emotional starting with short, sudden illness and death of our father, separation from his wife 2 months later with divorce ongoing, then met his 'soul mate'- bought a house together and moved in only to discover she was an a alcoholic- this relationship ended after about 11 months- they sold the house and my brother moved back in with our mother.

I suppose my question is could his symptoms be explained by stress/ grief?
He doesn't seem depressed particulalry but given the history I am sure  it is a distinct possibility.
Do you think his symptoms would warrant referral for full neurogical eaxamination?

If these symptoms are likely to be a psychological origin what can done to help him recover?

Many thanks