Health Technology Assessment on a Stepped Model of Care for Major Depressive Disorder and Generalized Anxiety Disorder

Condition Description – Major depressive disorder (MDD) and generalized anxiety disorder (GAD) cause significant impairment in the quality of life and function of patients. Anxiety is even more disabling in terms of a drop in quality of life during the acute phase. Subthreshold symptomatic patients are those who demonstrate depression and anxiety symptoms but do not yet meet the diagnostic criteria.

MDD can be episodic, meaning patients can experience several major depressive episodes in their lifetime with relatively normal mood and function in recovery periods between episodes. Major depressive disorder is among the top five leading causes of disability worldwide according to the Global Burden of Disease Study and is associated with adverse long-term outcomes, such as the increased risk for several chronic conditions including cardiovascular disease and chronic pulmonary disease.

GAD is a recurring mental health condition that is characterized by excessive, difficult to control anxiety and worry about multiple events or activities.

Current treatment options – The majority of patients with major depressive disorder and generalized anxiety disorder being cared for under the public system receive pharmacotherapy. This makes pharmacotherapy with access to psychotherapy at tertiary care the most representative intervention for the current status in BC. However, for patients not severe enough for tertiary care, and for those who have a preference not to begin medication, treatment choices are very limited.

Description of the Assessed Technology(ies) - A BC-based committee of mental health experts, including psychiatrists, clinical psychologists, health authority representatives, and other health professionals, designed the stepped-care model proposed for the treatment of major depressive disorder and generalized anxiety disorder (the BC stepped-care model).

There are four steps in the stepped-care model ranging from low-intensity interventions to specialized treatment for severe patients in tertiary facilities. Psychotherapy interventions are an educative approach, through collaboration, to help the patients learn to recognize, evaluate and correct negative thoughts and behaviours. They help patients build lifelong skills to personally manage their symptoms and their long-term mental health. Some interventions may be combined with pharmacotherapy within this approach.

Health Technology Assessment Committee’s Findings:

After reviewing the available evidence, the Health Technology Assessment Committee found:

• Psychotherapy can result in the substantial reduction of both duration and the number of episodes in both MDD and GAD, which in turn leads to a lower risk of recurrence, and a lower cumulative number of episodes over a lifetime.
• The use of the BC stepped-care model to treat a single cohort of incident patients compared to 'pharmacotherapy with access to psychotherapy at tertiary care only', over a 20-year time horizon, demonstrates substantial potential cost avoidance, as such, is not only cost-effective as compared to the status quo, but cost-saving.
• Based on the established clinical efficacy of the components of the stepped-care model and the high degree of confidence in the results of the cost-effectiveness analysis, there is substantial evidence in support of the public provision of a stepped-model of psychotherapy services for those with anxiety and depression.
• Given the substantial change management required to provide psychotherapy services earlier in the onset of illness and by different cadres of clinicians than is currently done, planning should include broad representation from those providing mental health services, including general practitioners, and the establishment of a patient-centered performance monitoring process as changes to service delivery are made.

It will be at the discretion of mental health sector partners to balance the considerable implementation considerations with the benefits of stepped psychotherapy for major depressive disorder and generalized anxiety disorder.