When does hospitalization in a psychiatric hospital become necessary ?

Certainly a person who, due to mental disorder, endangers themselves or others should undergo hospital treatment. It is best explained with an example: if the patient is convinced that he has become the target of a conspiracy, treats the people who surround him as his enemies who are trying to harm him in different ways, e.g. poison water and food, emit harmful radiation, lurk to kill him, you can expect the patient to take steps in order to defend himself. Not infrequently, convinced of defending his own life, the patient is so intimidated that he begins to attack his alleged persecutors. Obviously, hospitalization is inevitable in such a case.
The presence of suicidal tendencies is another example of the need for hospital treatment. A person overwhelmed by a thought of suicide should be under the strict supervision of the people that are able to prevent a possible suicide attempt. Not always the closest are able to provide the patient with proper care, and, then the hospital should take care of him.
The above example illustrates the situations of absolute necessity of hospitalization. Apart from these situations, there are much more where hospitalization is necessary as it can provide the best way of effective treatment.