When sleepiness is excessive, undesirable, inappropriate or unexplained, it 
often indicates a clinical disorder that is generically termed hypersomnia. One 
of the leading causes of hypersomnia is sleep apnea. We present the case of a 
44-year-old woman with a history of bipolar spectrum disorder and epilepsy who 
initially showed evidence of hypersomnia. The hypersomnia settled with changes 
to her medication, but the patient was subsequently found to have severe 
obstructive sleep apnea. The relation between the patient's medication and sleep 
apnea is discussed, and the possible respiratory-suppressant effects of chronic 
barbiturate treatment are considered. The role of other evoking factors within 
the context of this case and the mechanisms by which drug interactions and 
psychotropic treatment may worsen, obscure or perpetuate sleep apnea are also 
examined.