Introduction
Mental health and neurology intersect in ways that matter for patient outcomes and healthcare planning. This systematic review synthesizes evidence on the prevalence of mental disorders among people with neurologic conditions in Nigeria, following established guidelines (PRISMA and JBI). The study maps how common psychiatric comorbidities are in stroke survivors, people with epilepsy, and other neurologic conditions, and explores sociodemographic and regional factors that shape risk. The findings illuminate the substantial burden and underscore the need for integrated neuropsychiatric care in Nigeria.
Methods in brief
Researchers searched PubMed/Medline, EMBASE and African Journals Online for Nigerian studies from January 2010 to July 2024. Eligible studies diagnosed mental disorders via physician assessment or standardized screening tools and focused on populations with neurologic conditions. Cross-sectional designs were included, while case-control studies and non-human research were excluded. Data were extracted using standardized forms, and risk of bias was assessed with the NIH Quality Assessment Tool. A random-effects model pooled prevalence estimates when data allowed, with heterogeneity explored through I² statistics and meta-regression.
Key findings: major depression among stroke survivors
Across nine studies including 2,545 stroke survivors, the pooled prevalence of major depression was about 26.9% (95% CI: 16.4%–40.8%; I² = 95%). Regional variation was evident: prevalence was highest in the South-West and South-East regions (roughly 34% and 29%, respectively) and lowest in the North-Central region (about 6%). Meta-regression implicated age, female sex, and location as important moderators. Education played a complex role, with both no education and tertiary education associated with higher odds of depression in some analyses, suggesting SES dynamics may influence risk or reporting. Diagnostic methods varied (SCAN, PHQ-9, BDI, MINI), but none fully explained the heterogeneity.
Anxiety and other disorders among stroke survivors
Two studies reported anxiety disorders among stroke survivors, with one study indicating a prevalence around 21% using SCAN. Generalized anxiety disorder (GAD) appeared less common, estimated at about 9.6% in a single study. Sleep disturbances were also noted, with insomnia and hypersomnia affecting notable minority groups. These findings point to a spectrum of psychiatric comorbidities that can impair functional recovery and quality of life after stroke.
Epilepsy and associated psychiatric comorbidity
In epilepsy, the pooled prevalence of major depression was approximately 11.9% (95% CI: 6.2%–21.6%; I² = 92%), with adult cohorts showing lower rates than a 30.8% figure reported in one adolescent-focused study. Among adults, dysthymia occurred in about 11.4% of people with epilepsy in Kano. Overall, depressive disorders in epilepsy contribute to poorer seizure control and reduced daily functioning, reinforcing the bidirectional relationship between epilepsy and mood disorders.
Other neurologic conditions
When considering neurologic conditions as a whole, major depression prevalence stood at roughly 17.6% (95% CI: 10.5%–28.0%; I² = 97%), with regional differences again apparent. Generalized anxiety disorder (GAD) pooled at about 6.4%, while psychosis and somatic symptom disorders appeared at lower, but non-negligible, frequencies in specific Nigerian contexts. Collectively, the data suggest a meaningful mental health burden among Nigerians with neurological disease across conditions, not limited to stroke and epilepsy.
Implications for practice and policy
The high co-occurrence of depression and other psychiatric disorders in neurologic patients has tangible consequences: greater mortality risk, increased functional dependency, and poorer rehabilitation outcomes. Early identification through routine mental health screening in neurology clinics, integrated neuropsychiatric care, and culturally appropriate interventions could improve outcomes. Training for frontline health workers and expansion of mental health services in neurology settings are essential steps, alongside regionally tailored strategies that address socioeconomic and educational disparities.
Limitations and gaps
Limitations include substantial heterogeneity among studies, varying diagnostic tools, and geographic concentration in urban areas, which may limit generalizability to rural Nigeria. There are relatively few studies on anxiety, GAD, and other disorders, and data on other neurologic conditions beyond stroke and epilepsy remain sparse. Future research should aim for standardized diagnostic criteria, broader geographic coverage, and longitudinal designs to track incidence and outcomes over time.
Conclusions
Among Nigerians with neurologic conditions, major depression is notably prevalent, with regional and demographic variations. The burden extends to anxiety and other psychiatric disorders, underscoring the critical need for integrated, accessible mental health care within neurology services. Addressing these comorbidities could improve recovery trajectories and overall quality of life for individuals living with neurological disease in Nigeria.
