Co-morbid anxiety disorders in patients with schizophrenia in a tertiary institution in South East Nigeria: prevalence and correlates

Background: Anxiety disorders occur commonly in schizophrenia but are often overlooked by psychiatrists. Their presence may compound the challenges faced by these patients and may contribute to poor outcome. Objectives: The purpose of this study was to determine the prevalence of anxiety disorders among the participants with schizophrenia, and the association between this co-morbidity and disability. Method: A total of 367 participants were recruited from the out-patient department of Federal neuropsychiatric hospital Enugu, Nigeria. Socio-demographic questionnaire, schedules for clinical assessment in neuropsychiatry, positive and negative syndrome scale and the 12-item version of the World Health Organization disability assessment schedule were administered.Results: A total of 189 females (51.5%) and 178 (48.5%) males were studied. A lifetime prevalence of 12.3% was reported for anxiety disorder. Anxiety disorder was more likely in females (x²=4.93, p 0.03). Specific prevalence for anxiety disorder in schizophrenia was generalized anxiety disorder 6.3%, obsessive compulsive disorder 3.3%, and phobic anxiety disorder 2.7%. Anxiety disorder was associated with increased disability (t=3.50, p 0.001) and psychopathology (t=3.40, p 0.001) among the participants studied. Phobias were associated with prescription of low doses of antipsychotics(x²=4.08, p 0.04). There was a low rate of identification of anxiety disorder in routine clinical practice (k=0.08, p 0.001). Conclusion: Co-morbid anxiety disorders are common in schizophrenia and they are associated with increased disability and psychopathology. The results emphasize the need to screen for anxiety disorders in patients with schizophrenia.