Since its introduction in Brazil in 1977, the CLP service has been the link between patients, family, medical staff, and external health services in the field of mental health. In many cases, it is also the first opportunity for psychiatric care, further emphasizing the importance of this service [3, 9, 10, 11]. CLP services are present in 86% of general hospitals, with the vast majority in university hospitals [9, 12-14]. To the best of our knowledge, this is one of the largest studies on Brazilian CLP services, which involved an elevated number of requests (2,742), and with a large time interval (six years).
The number of CLP requests corresponded to 0.73 to 1.50% of the total hospital admissions in the period. Studies with different follow-up periods have disclosed that CLP requests correspond to 0.9-2% of all hospital admissions [13-22]. Despite the similarity to literature, this frequency remains below what is expected from the prevalence of mental disorders in Brazil [21,23]. One reason for this discrepancy is probably the passive screening by the CLP teams .
The sociodemographic characteristics observed in this study agreed with other published reports in the field [15-31]. Similarly to other long-term studies, the geriatric population corresponded to almost 10% of the sample [15, 16]. Another study conducted at the Hospital de Base of Sao Jose do Rio Preto from 2010 to 2014 showed that 14.33% of the consultations were made for elderly patients, which is the same proportion as our data . In contrast, Bambarén  found 41.6% total psychiatric consultations for the elderly population in Rio Grande do Sul, Brazil and Wancata , with 45.3% in a hospital in Vienna, Austria. The difficulty in managing these patients, since they may have greater morbidity, comorbidities, and drug interactions, may be obstacles to psychiatric consultation in the coming years.
The CLP response time was in agreement with other studies, with a large portion being answered before 48h . In this study, a faster response was observed for the Emergency sector, due to the serious nature of the cases (p<0.001). In addition, the time between admission and request for consultation (lag time) was also consistent with other studies, varying between 3 and 15 days [13, 15, 19]. In a study by Nakabayashi , endocrine, metabolic, and nutritional conditions were observed and early consultations were requested, due to dysfunctional conditions that required rapid intervention. In cases where there was no possibility of evaluation, it was observed in this study that such cases occurred in the ICU (p<0.001). As the main change was "intubation", a better communication between the teams seems to be essential. Such data have not been frequently related in other studies in this field; this sheds light on this very common occurrence in general hospitals.
Regarding the frequency of the teams that requested CLP evaluation, Internal Medicine has been the most frequent [13, 15, 16, 19, 21, 28-30]. This finding would be associated with the possible greater sensitivity and accuracy of clinicians in detecting behavioral alterations. Furthermore, according to Kishi et al. , clinical physicians have higher measures of empathy than those in specialties focused on technology, such as anesthesiology, surgery, and other surgical subspecialties, which may explain the reason for delays or lower demands on surgical wards.In addition, the infirmary was the location of more than half of the cases of CLP requests. This finding was discordant to what has been found in other studies; Huyse  observed that the emergency corresponded to 33% of the service, mainly due to suicide attempts, self-mutilation, and intoxication by psychoactive substances [33,34].
Regarding psychiatric diagnoses, in a study by Magdaleno et al , the main diagnoses were adjustment disorder (24.6%), depression (23%) and organic psychotic conditions (18.8%). In another Brazilian research, the psychiatric disorders were depression, adjustment and personality disorders . A 30-years study by Nakabayashi (2012) showed mood disorder (40.4%), neurotic disorders (13.8%), substance use disorders (12.8%) . At the international level, in a collaborative study of 56 services from 11 European countries, the main causes of solicitation were self-mutilation (17%), substance abuse (7.2%), current psychiatric symptoms (38.6%) and unexplained physical complaints (18.6%) . Bellomo et al.  observed that mood disorders (most common) occurred in 10-50%, adjustment disorder in 3-19%, and anxiety disorders in 0-18% of patients [10, 13, 17, 18, 19, 20, 21, 28, 31]. However, other diagnoses are also important. Regarding substance use disorders, despite its importance and elevated frequency of diagnoses, it is still much lower than the overall prevalence in Brazil; as in other studies, it shows that the treatment is focused on acute conditions (intoxications and abstinence), and not so much for the dependence itself [13, 36].
As for the therapeutic plan, the majority have focused on drug treatment, as well as other research . Antidepressants have been selected in most cases in several studies [21, 25, 32]. After discharge, the patient was referred to a service for follow-up if necessary. In a study by Rigatelli , psychiatric outpatient clinics were the main destination (29%), followed by primary care units (27%), private practices (8%), and maintenance of hospitalization (6%).
Most studies in the field of CLP seek to show the cost savings of this type of service, but there are important methodological flaws, the impossibility of building an adequate control group, short follow-up time, absence of prospective data, and standardized documentation [9, 15, 37]. This absence of quality indicators conveys the erroneous feeling that the CLP service does not produce anything or does not have concrete goals . Therefore, as long as randomized clinical trials are not carried out, it is important to complement them with retrospective/prospective studies to record the evolution and development of the CLP service [16, 39]. Moreover, due to the low percentage of requests compared with total hospital admissions, the CLP has been mostly seen as a reactive measure by general hospitals to obtain emergency psychiatric care, rather than as a mental health strategy. Therefore, CLP services often suffer from exclusive issues such as stigma, financial disincentives, lack of an adequate multidisciplinary team, or low remuneration [38, 40-42]. This is reflected in the high turnover of the CLP team, often with a short experience and less production of research data [13, 27, 43, 44].
The present study has several limitations. Despite being a relatively long-term study, as it is transversal and retrospective, it does not reflect the national reality. Different hospital configurations, consultants, study periods, sample sizes, and diagnostic classification systems can cause heterogeneity with other services. Standardized psychiatric scales and structured clinical interviews were not used in this study. Due to the methodology, the patients' hospitalization time and other interesting data, such as adherence by the team, were not obtained.