Overview
This systematic review, conducted in Nigeria, evaluates how common mental disorders are among people living with neurologic conditions. Following established methodological guidelines from PRISMA and the Joanna Briggs Institute, the study synthesizes data from 18 Nigerian studies (2010–2024) involving 4,457 participants across eight states. The focus is on disorders diagnosed by clinicians or identified via standard screening, with emphasis on major depression, anxiety disorders, epilepsy-related psychiatric comorbidities, and other neuropsychiatric conditions.
Methods in brief
Researchers searched PubMed/Medline, EMBASE, and African Journals Online, screening for studies that enrolled Nigerians with neurological conditions and reported mental health outcomes. Study designs were primarily cross-sectional or survey-based, and prevalence estimates were pooled using random-effects meta-analysis to account for heterogeneity. Diagnoses used include the SCAN, PHQ-9, BDI, MINI, and related tools. Risk of bias was assessed with the NIH tool, and certainty in the evidence was rated with an adapted GRADE approach.
Inclusion criteria and data synthesis
Eligible studies needed: (1) Nigerian setting, (2) a neurologic condition population, and (3) data on mental disorders. Case-control designs were excluded, as were reviews and non-human studies. Where possible, analyses explored sociodemographic moderators such as age, sex, and geography, using meta-regression to illuminate regional and demographic patterns.
Key findings: major depression across neurologic conditions
Across all included studies, the pooled prevalence of major depression among people with neurologic conditions in Nigeria was about 17.6% (based on 3,832 participants). Depression rates were higher among stroke survivors and were notably influenced by age, sex, and geographic region. Meta-regression indicated that each additional year of age increased the odds of depression by about 6%. Female patients showed slightly higher prevalence, and the southern regions (South-South and South-West) reported the highest rates, while the North-Central region showed the lowest.
Stroke survivors: depression and broader mood concerns
For stroke survivors specifically, the prevalence of major depression averaged around 26.9% across studies. Regional differences emerged: about one-third of stroke survivors in the South-West and South-East regions were found depressed, compared with roughly 6% in the North-Central region. Beyond depression, some studies noted anxiety (around 21% in a Lagos-area sample) and sleep disturbances, highlighting the broader neuropsychiatric impact of stroke on quality of life and functional outcomes.
Epilepsy and other neurological conditions
Among people with epilepsy, major depression prevalence tended to be lower overall (roughly 11.9%), though adolescents with epilepsy showed markedly higher rates (about 30% in one study). Generalized anxiety disorder (GAD) presented more modestly (pooled around 6.4% for certain Nigerian cohorts), with individual studies reporting wide variation. Other psychiatric disorders, including psychosis and somatic symptom disorders, appeared less frequently but remained clinically important, underscoring the heterogeneity of neuropsychiatric comorbidity.
Implications for care and policy
The review underscores a substantial mental health burden among Nigerians with neurologic conditions, particularly depression after stroke and comorbid depression in epilepsy. These findings exceed general population prevalence rates and highlight the need for integrated neuropsychiatric services. Routine mental health screening in neurology clinics, targeted treatment pathways, and training for frontline healthcare providers could improve outcomes and reduce mortality, functional decline, and poorer quality of life.
Strengths, limitations, and future directions
Strengths include a comprehensive search across multiple Nigerian states and rigorous bias assessment. Limitations involve geographic clustering (urban centers dominate samples), variability in diagnostic tools, and limited data on anxiety and other disorders in some neurological groups. Future work should expand rural sampling, standardize diagnostic criteria, and explore etiological pathways linking neurological injury with psychiatric sequelae using longitudinal designs.
Conclusion
In Nigeria, mental disorders, especially major depression, are common among people with neurologic conditions. The findings call for integrated care models that address both neurological and psychiatric needs, tailored to age, sex, and regional contexts to improve recovery and quality of life for affected individuals.
