The construct of generalized anxiety disorder in Alzheimer disease

The objectives of this study were to examine the criterion validity in Alzheimer disease (AD) of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and the International Classification of Diseases, 10th Revision (ICD-10) criteria for generalized anxiety disorder (GAD), to clarify the symptoms associated with excessive anxiety and worry in AD, to examine the co-occurrence of GAD and depression in these patients, and to determine the neuropsychologic and functional impact of GAD in AD.

One hundred forty-four of a consecutive series of 552 patients with probable AD (26%) reported excessive anxiety and worry difficult to control for most of the 6 months before the psychiatric evaluation. Excessive anxiety and worry were significantly associated with restlessness, irritability, muscle tension, fears, and respiratory symptoms of anxiety. Using these symptoms as diagnostic criteria, 56 of the 552 patients (10%) met revised diagnostic criteria for GAD as compared with 15% when using DSM-IV criteria and 9% when using the ICD-10 criteria. GAD was present in 38 of the 144 patients (26%) with major depression and in 12 of the 261 patients (5%) without depression. Patients with both GAD and depression showed more severe cognitive deficits than patients with either GAD or depression only.

The authors validated a set of diagnostic criteria for anxiety in dementia. These criteria include restlessness, irritability, muscle tension, fears, and respiratory symptoms in the context of excessive anxiety and worry. Anxiety in AD is a frequent comorbid condition of major depression.