Communicating an intention to commit suicide or communicating the occurrence of suicidal ideation can be a cry for help. There is one particular Psychiatric Illness - Bipolar Personality Disorder - to which communicating suicidal intent as a (poor) strategy for eliciting caring behavior from others is common. There are various levels/stages of suicidality and the experience can be transient, so it is also the case that people may communicate suicidal intent/ideation when the experience reduces or becomes less intense. For example, a person may feel intensely suicidal on one day and then report this to a professional at a later time when the feeling has reduced. People are often very scared by the occurrence of suicidal ideation and this is often the reason they report the experience to professionals. Also, people can feel intensely suicidal even when they have a clear wish not to die! As a serious psychiatric symptom thoughts of suicide can be completely counter to a persons moral, spiritual or intellectual standards.
Like most things in the field of mental health sucidality does not fit neatly into a categories. It is not that case that people are either suicidal or not, rather it is the case that suicidality is a highly varied experience that differs from person to person and over time.
I hope this has been of some help. Please let me know if you have further questions or would like me to clarify part of my answer.