A yоung аdult аrrives аt the emergency department accоmpanied by a family member with repоrts of hopelessness, low energy, and suicidal ideations. The family member reports the patient has been acting strangely for the past eight months, including writing on the floor, talking to themselves, and showing no interest in academic studies or social events. The patient has been hearing voices for four weeks and began to suspect that they were a part of a CIA conspiracy several weeks ago. Over the past year, they have experienced intermittent episodes of depressed mood lasting a total of 6 months. Which of the following is the most likely cause of this patient's symptoms?