Examine the text below and answer the subsequent query according to the details provided.

The newest statistics have been released. 9,180 youths with psychiatric disorders, 150 suicide casualties, and five residents diagnosed with severe depression and developmental disorders have lost their lives. Although these tallies are publicized, it remains unclear what specific conditions are classified as a psychiatric disorder, and whether these counts are restricted to individuals in specialized therapeutic units or if they encompass residents in general dormitories who are taking psychiatric drugs. Furthermore, we are left in the dark about when the onset of these conditions occurred, the specific diagnoses involved, or their duration of stay in these institutions. The National Juvenile Justice Bureau's (NJJB) Reformatory Statistics Report for the year 2021 has been published. It is worth reiterating that a mental health crisis is ravaging reform facilities.

We frequently hear that the purpose of correctional sentencing is reformation and rehabilitation. However, observing the actual environments where these sentences are served reveals conditions that, far from fostering rehabilitation, breed despondency, hopelessness, and vulnerability. In fact, these juvenile facilities are not filled mostly with sentenced offenders; rather, temporary detainees make up more than 70% of the institutional population. Over half of the youths diagnosed with psychiatric disorders were temporary detainees. Nevertheless, the true numbers might be significantly greater. For example, Project Youth's assessment on psychiatric health in maximum-security settings, titled Desolate Youth, revealed that more than 60% of high-risk juveniles suffered from an active psychiatric episode, but many had not been recognized by the facility administration as requiring clinical intervention. Desolate Youth also indicated that self-destructive actions had very little connection to clinical diagnoses, but were heavily linked to a lack of social support, systemic violence, trauma, and despair.

The National Mental Health Strategy, 2014, designates juvenile detainees as a group highly vulnerable to psychological distress. Yet, while the NJJB data corroborates this classification, it offers no actionable path forward for designing interventions, leaving us without guidance. What causes such a high rate of psychiatric struggles among these youths? Did they suffer from these conditions prior to their admission, or did they experience their first episode during their confinement? The current administrative structure is unprepared to offer such crucial information. Contextualizing these statistics is vital, because without doing so, our default strategy will remain restricted to basic medicalization, and discussions will stall at the inadequate healthcare resources within detention centers.

Which of the following options is a synonym for the word 'onset' as it is used in the text?