Causes of Death in A Psychiatric Hospital?

What are the possible causes of sudden, unexplained  death in Psychiatric Hospital inpatient?

1-  Co -incident

2- High dose neuroleptics, first generation antipsychotics in high dose block the cell membrane sodium pump and this will decrease the cardiac conduction velocity with consequent decrease of heart rate and contraction. This might alter or result in ventricular fibrillation, Howvere all mechanisms are self limited but may be fatal

3- Negative Ionotropic effect: this decreases cardiac output and Blood pressure , if it is catastrophic and not hydrated , it is fatal

4- CNS depression

5- Respiratory depression leads to hypoxia , seizures and suffocation

6-Terrifying hallucinatory experiences

7-suicide by mega dose pills  in response to ordering voices or intolerant derealization and depersonlization

8-Heavy smoking with hidden malignacy , suspected in nexplained weight loss

9- Homicide by strangulation in bed by room mate

10- Suffocation due to inhibited gag reflex  (predisoposed by neuroleptics) and regurged food during sleep

Refrence:

Thompson C, The use of high dose antipsychotic medication, BJP (1994),164,448-458