Register data are fully representative of the entire population with no loss to follow-up. Nationwide coverage also ensures a large sample to investigate events and conditions with low base rates. Clinical observations are limited and often only available for select patient populations. However, the opportunities available for public health research through linkage of register data with the increasing number of nationwide clinical databases, bio-banks and surveys entail promising perspectives for future research.

Collectively, frequent callers have a significant impact on crisis lines, and solutions need to be found for responding to them that are in everybody's best interests (i.e. the frequent callers themselves, other callers, telephone crisis supporters who staff crisis lines, and those who manage crisis lines). In striking this balance, the complex and multiple needs of frequent callers must be taken into account.

Suicide is a serious public health problem, with more than 800,000 deaths taking place worldwide each year. Mental disorders are associated with increased risk of suicide. In schizophrenia and other psychotic disorders, the lifetime risk of suicide death is estimated to be 5.6%. The risk is particularly high during the first year of the initial contact with mental health services, being almost twice as high as in the later course of the illness. The most consistently reported risk factor for suicide among people with psychotic disorders is a history of attempted suicide and depression. Suicide risk in psychosis in Denmark decreased over time, most likely because of improved quality of inpatient and outpatient services. There is a high proportion of young people with first-episode psychosis who attempted suicide before their first contact with mental health services. This finding suggests that the mortality rates associated with psychotic disorders may be underreported because of suicide deaths taking place before first treatment contact. However, currently, no data exist to confirm or refute this hypothesis. Attempted suicide can be an early warning sign of later psychotic disorder. Data from different studies indicate that the risk of suicide attempt during the first year of treatment is as high as 10%. The most important risk factors for attempted suicide after the first contact are young age, female sex, suicidal plans, and a history of suicide attempt. Early intervention services are helpful in first-episode psychosis, and staff members should, in collaboration with the patients, monitor the risk of suicide and develop and revise crisis plans.

Preventive efforts need to target the period close to discharge from emergency departments.