Delirium during hospitalization affects up to seven million adults every year, increases the likelihood of needing post-acute or nursing home care and doubles a patient’s risk of death. And, according to a new study, there is no way to prevent or treat it.

Indiana University researchers reviewed decades of delirium research and concluded that not much has been done to ameliorate the condition among adults. In fact, their report says, only 13 clinical trials of potential delirium medications were conducted between 1966 and 2008. According to one report author, current research on the causes and potential treatments of delirium is at roughly the same place Alzheimer’s disease research was 30 years ago.

Older adults are especially vulnerable to delirium, which can set in even after relatively minor medical complications, such as urinary-tract infection or sleeping pill use, according to report authors. Their research has found that, while no approved remedy currently exists, drugs that alter the sleep-wake cycle, or that manage pain after surgery, may help prevent delirium. The report appears in the July issue of The Journal of General Internal Medicine.