Relations between clinical characteristics and cognitive deficits among adult patients diagnosed with major depressive disorder

Abstract

Objective

The present study examined the relations between clinical characteristics and cognitive deficits in adult patients with major depressive disorder (MDD) from a local outpatient psychiatric clinic in Malaysia.

Methods

The present sample included 110 participants aged 20–60 years old. Participants were invited to provide their information on sociodemographic variables (age, gender, and educational level) and clinical characteristics (age at onset of depression and duration of illness) and to complete a series of cognitive performance measures including the Trail Making Tests A (psychomotor speed) and B (executive function), the Digit Symbol Substitution Test (attention), and the Auditory Verbal Learning Test (immediate free recall, acquisition phase, and delayed recall). The Mini International Neuropsychiatric Interview Version 6.0 was used to confirm the diagnosis of MDD and the Montgomery–Åsberg Depression Rating Scale was used to assess illness severity.

Results

At the bivariate level, relations of age and educational level to all cognitive deficit domains were significant. At the multivariate level, only educational level and illness severity consistently and significantly predicted all cognitive deficits domains.

Conclusions

Therapeutic modalities should be individualised whilst considering the impacts of cognitive deficits in an attempt to prevent further deterioration in psychosocial functioning of MDD patients.

KEY POINTS

• Cognitive deficits are an elemental component of Major Depressive Disorder (MDD) persisting during a current major depressive episode or during remission, altering individuals’ ability to process information and changes the way they perceive and interact with the environment.

• Cognitive deficits in MDD are evident among the upper-middle income groups in South-Eastern Asian countries warranting more local research as such deficits could lead to functional decline and work performance such as absenteeism and presenteeism.

• Therapeutic modalities should be individualised by taking the impacts of cognitive deficits into consideration to promote psychosocial functioning of MDD patients.

Keywords:

• Age at onset of depression
• duration of illness
• illness severity
• Major Depressive Disorder
• cognitive deficits

Acknowledgments

The authors would like to thank the Director General of Health Malaysia for his permission to publish this article. The authors would like to thank the Director, Hospital Kuala Lumpur and the Head, Department of Psychiatry and Mental Health of Hospital Kuala Lumpur for their permission to conduct the present study in Hospital Kuala Lumpur. The first author is grateful to Mr. Premnath Agamutu for his help in data entry. This paper is based on a dissertation submitted by Natasha Subhas in fulfilment of the requirements for the degree of Master of Medicine (Psychiatry) at Universiti Putra Malaysia.

Institutional review board statement

The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the National Medical Research and Ethics Committee of the Ministry of Health, Malaysia via the National Medical Research Registry (NMRR-16-1190-31473[IIR]) and the Ethics Committee for Research Involving Human Subjects, Universiti Putra Malaysia.

Informed consent statement

Written informed consent was obtained from all participants involved in the study.

Author contributions

NS, JK A, K-A T, and SNAA designed the study. NS and SNAA collected the data. NS and K-A T analysed the data and discussed the results. NS drafted the manuscript. JK A and K-A T reviewed and revised the manuscript. All authors read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data set supporting the conclusion of this article is available on reasonable request to the corresponding author.