Clinical Summary
Clinical Summary: Comorbidity Patterns of Anxiety and Depressive Disorders in a Large Cohort Study: the Netherlands Study of Depression and Anxiety (NESDA)
Patients rarely present with a "pure" depressive disorder or anxiety disorder, and missing the second diagnosis can underestimate severity, chronicity, and treatment needs. In this large NESDA cohort, comorbidity was the rule rather than the exception and was linked to more childhood trauma, higher neuroticism, earlier onset, longer symptom duration, and greater symptom severity.
Design
Baseline data (N = 1,783) of the Netherlands Study of Depression and Anxiety, collected between September 2004 and February 2007, were used.
N
N = 1,783
Population
We included all persons with a current (12-month) diagnosis of depressive and/or anxiety disorder (N = 1,783).
Duration
current (12-month)
Key Findings
- Comorbidity was very common: of those with a depressive disorder, 67% had a current and 75% had a lifetime comorbid anxiety disorder; of persons with a current anxiety disorder, 63% had a current and 81% had a lifetime depressive disorder.
- Comorbidity was associated with a more severe and chronic clinical profile, including more childhood trauma (OR = 1.19; 95% CI, 1.06–1.33), higher neuroticism (OR = 1.05; 95% CI, 1.02–1.08), earlier age at onset of first disorder (OR = 1.59; 95% CI, 1.22–2.07), longer duration of depressive and/or anxiety symptoms (OR = 1.01; 95% CI, 1.01–1.01), and higher symptom severity (ORs ranging from 1.01 to 1.03; all P values < .05).
- Among 1,783 patients with a depressive or anxiety disorder, 40% had only 1 disorder, 30% had 2 depressive or anxiety disorders, and another 30% had ≥ 3 depressive or anxiety disorders.
- In 57% of comorbid cases, anxiety preceded depression, compared with 18% in which depression preceded anxiety and 25% with simultaneous onset.
- Among specific disorders, generalized anxiety disorder showed the highest depressive comorbidity, with 76% having current and 86% having lifetime MDD, while social phobia preceded depressive disorders in 67% of the cases.
Clinical Bottom Line
Routine bidirectional screening for depressive disorders and anxiety disorders should be standard practice, regardless of the presenting complaint. Comorbid cases identify a distinctly higher-burden group with greater severity, longer duration, and earlier onset that may require more intensive management.
Practice Implications
- Assess for both depressive disorders and anxiety disorders at intake even when one syndrome appears primary, because 67% of those with a depressive disorder had a current comorbid anxiety disorder and 63% of those with a current anxiety disorder had a current comorbid depressive disorder.
- Treat comorbid presentations as higher-risk cases: more childhood trauma, higher neuroticism, earlier age at onset, longer duration of symptoms, and higher symptom severity were all independently associated with comorbidity.
- Be especially alert for mixed presentations in dysthymia and generalized anxiety disorder, since rates were higher for those with dysthymia than for those with MDD, and comorbidity with depressive disorders was highest in GAD.
- Do not assume depression always comes first; in 57% of comorbid cases anxiety preceded depression, while generalized anxiety disorder most often had simultaneous onset with the depressive disorder (41%).
