Latent Class Analysis in Depression, Including Clinical and Functional Variables: Evidence of a Complex Depressive Subtype in Primary Care in Chile

Latent class of depressive symptoms of and its determinants: A cross-sectional study among Iranian University students

Background

According to the report of the World Health Organization, mental disorders are one of the 10 most important causes of disability in the world. This study was conducted with the aim of determining the number and frequency of latent classes of depression and its determinants in Isfahan university of medical students.

Materials and Methods

A total of 1408 medical students from Isfahan University of Medical Sciences, Iran, were enrolled in the study in 2017. The symptoms and severity of depression were assessed using the standard Hospital Anxiety and Depression scale questionnaire. Latent class analysis was applied to seven symptoms of depression, all of which had four levels. Latent class subgroups were compared using the Chi-square test and analysis of variance test. The regression model was used to check the relationship between identified classes and related factors. Analyzes were done using SPSS-21 and Mplus7 software.

Results

In this study, three latent classes were identified, that is, the group of healthy people, the group of borderline people, and the group of people suspected of depression. The prevalence of identified latent classes among medical students is 0.52, 0.32, and 0.16%, respectively. The regression results showed that compared to the healthy group, the factors affecting depression in the borderline and suspicious group were increasing age, female gender, interest in the field of study, physical activity, history of depression, and history of anxiety.

Conclusion

The three classes that were identified based on the students' answers to the depression symptoms questions differed only based on severity. The history of depression and anxiety were the strongest predictors of latent classes of depression.

Evolution of Depressive Symptoms Among Depression Subtypes of Clinical and Functional Variables in Primary Care in Chile

OBJECTIVE

To compare the evolution of depressive symptoms among depressive subtypes based on clinical and functional variables in a sample of primary care in Chile.

METHODS

A longitudinal study was conducted in the Maule Region of Chile, focusing on 8 primary care from February 2014 to September 2015. Clinical and functional variables, including Mini International Neuro-psychiatric Interview, Outcome Questionnaire interpersonal and social sub-scales, were applied in a latent class analysis. This analysis categorized 210 patients into 3 subtypes: complex depression (N = 100), recurrent depression (n = 96), and unique depression (n = 14). Complex depression, exhibited a higher probability of suicide attempts, interpersonal and social dysfunction, and association with adverse childhood experiences according the Brief Physical and Sexual Abuse Questionnaire. Patients were monitored over 1 year with the Hamilton scale. The Kruskal-Wallis, non-parametric test, followed by paired Mann-Whitney test evaluated difference in the severity of depressive symptoms between the groups. Additionally, data on mental health interventions were collected.

RESULTS

Out of the 210 patients, 89% were women, with a median age of 50 (range 37-58), and 40.1% with only primary education. Sociodemographic characteristics not differ between groups. Significant differences in depressive symptom severity between the groups were found (X2 90.06, P < .001, Kruskal-Wallis test, η2 = 0.084). Post hoc analyses indicated higher depressive symptoms in complex depression compared to recurrent (Z = -9.501, P < .001) and unique (Z = -2.877, P = .004) depression, with no significant difference between recurrent and unique depression (Z = -1.58, P = .113). There were no differences in the number of medical and psychological controls between the groups. The patients with complex depression required greater modifications in the pharmacological prescriptions than those belonging to the other groups.

CONCLUSION

These results provide additional evidence of a complex depression subtype in primary care in Chile associated with adverse childhood experiences, that had worse resolution of depressive symptoms. Contrary to expectations, patients belonging to this group did not receive further medical and psychological interventions, probably due to a lack of specific clinical recommendations.