My friend has schizophrenia and he's tired all the time :/ (NEED YOUR HELP)

This might be a bit long but PLEASE bare with me..

So long story short, my friend was diagnosed with schizophrenia like 2 years ago and I've been with him ever since (on and off) on an insane healing journey.

Right now he's taking medication and his hallucinations are almost completely gone (thankfully)

However, he gets EXTREMELY burnt out from doing basic things. This can be as talking to people, doing some work on his laptop or even taking a simple walk.

This is obviously a HUGE problem because he's unable to work or develop any skills. The longest he can go without burning out is around 1 hour of focused work.

Now I know this is a common symptom of schizophrenia, but is there any way to alleviate this? Please share with me what worked for you!

Is this psychological? or does he possibly need his medication changed?

If you have any questions about him please let me know!

Quick description of his daily routine:
He goes to the cafe, smokes hookah and a cup of coffee. Takes a walk then spends the rest of the day home mostly sleeping.