Hi there, thank for asking. You are right in your observation, because many people with sleep apnea
may find change in the mood and energy level as well. A good strategy is to encourage him to lose weight. It can help for improvement in apnea. it should be at least 15 to 20 pounds to be effective. Honestly his BMI is very high and it makes the effectiveness of the CPAP lower than expected. He should also know that the CPAP pressure should also be adjusted during sleep assessment every one or two years to be effective. I wish him the best health.