in•som•ni•a /in'sämnēa/ Noun Habitual sleeplessness;inability to sleep. Emotional disorders that can cause insomnia include depression, anxiety, and posttraumatic stress disorder. ••• Unable to come to terms with the death of his girlfriend, 22 year old Xander struggles with depression, PTSD, and insomnia. He's ready to end it all until he forms an unexpected friendship with the feisty and self destructive 16 year old, Reagan, who talks him through sleepless nights and bad thoughts. And before long their harmless friendship turns into something a little less innocent. "I want to know the 3 AM you."