Depression, Depressionen

Vagus-Nerv-Stimulation (VNS):

VNS THERAPY NEWS FLASH ‐ ISSUE

The Recognition and Management of Mood Disorders as a Comorbidity of Epilepsy

As the incidence rate of depressive disorders, one of the most pressing worldwide medical problems, continues to increase, the need for early detection and adequate treatment is greater than ever. The detection and treatment of comorbid mood disorders among patients with other chronic conditions such as epilepsy, however, is even more problematic. This recent article by Barry discusses the importance of mood disorders in epilepsy as well as how to recognise and treat those disorders.

Physicians estimate that the average frequency of major depressive disorders among patients with epilepsy is 29% (ranging from about 8% to 48%) compared with a frequency range of 4.9% to 17% in the general population. Biological relationships between epilepsy and depression and psychosocial issues are two factors cited that increase the risk for comorbid mood disorders among patients with epilepsy. In addition, some antiepileptic drugs (AEDs) are known to cause or exacerbate mood disorders. Unique qualities of depression among the epilepsy population discussed in the article include the association of mood changes with seizure activity; pleomorphic depressive features with disabling symptoms; and somatic complaints that could be a factor of depression, AEDs, or the disease process, which can elevate depression scores on standardised tests. However, improved recognition of comorbid mood disorders among patients with epilepsy does not always equate to approved treatment.

Antidepressant drugs (ADs) are the primary and most useful pharmacological intervention for depressive disorders, but side effects (particularly the proconvulsant properties of ADs) and the potential for drug interaction complications with AEDs are problematic, thereby limiting the use and effectiveness of AD treatments. The use of nonpharmacological interventions, including cognitive, behavioural, and interpersonal therapy, have, unfortunately, yet to be extensively studied among this population, but may be useful interventions because of the psychosocial factors of depression among patients with epilepsy. Other potential treatment modalities include electroconvulsive therapy (ECT) and vagus nerve stimulation (VNS) Therapy. Although ECT is effective among patients with epilepsy, it is usually reserved for refractory cases (typically those with psychotic features). However, ECT is warranted and effective when a quick response is needed, particularly when the patient's immediate safety is at risk owing to suicidal ideations. VNS Therapy, an already-accepted treatment for refractory epilepsy, also is associated with positive mood effects independent of its effects on seizure control. In addition, open-label studies of VNS Therapy for the treatment of refractory depression are showing promising results. This new treatment option is safe and without the drug interactions associated with AED and AD therapies and, therefore, may prove to be a unique and effective long-term treatment option for epilepsy patients with comorbid mood disorders.

Source: Barry JJ. The recognition and management of mood disorders as a comorbidity of epilepsy.

Epilepsia 2003; 44:30-40.