Quetiapine for Major Depressive Disorder

Key Messages

What Is the Issue?

• Quetiapine is a second-generation antipsychotic (SGA) or atypical antipsychotic drug primarily used for treating schizophrenia and bipolar disorder. Quetiapine extended-release is also indicated by Health Canada for the symptomatic relief of major depressive disorder (MDD) when currently available approved antidepressant drugs have failed.
• Decision-makers are interested in understanding the evidence regarding quetiapine’s clinical effectiveness, safety, and place in therapy relative to other medications for the treatment of MDD.

What Did We Do?

• We searched key resources, including journal citation databases, and conducted a focused internet search for relevant evidence published since 2020.

What Did We Find?

• The evidence suggests that quetiapine and other SGAs (particularly aripiprazole, brexpiprazole, cariprazine, olanzapine, risperidone, and ziprasidone) have similar efficacy but have unique safety profiles when used for the treatment of adults with treatment-resistant MDD.
• The evidence also suggests that treatment with quetiapine reduced symptoms of treatment-resistant depression compared to treatment with lithium.
• Evidence-based guidelines recommend using quetiapine as a second-line augmentation treatment option for MDD in patients whose disease had partial or no response to an adequate dose of initial pharmacotherapy.
• The Canadian Network for Mood and Anxiety Treatments (CANMAT) guideline recommends atypical antipsychotics such as quetiapine in combination with an antidepressant as the first-line treatment for MDD with psychotic features. The Royal Australian and New Zealand College of Psychiatrists (RANZCP) guideline suggests using quetiapine as monotherapy or adjunct therapy for patients with major depression.

What Does It Mean?

• Quetiapine could be used as second-line augmentation treatment for MDD in patients whose disease had partial or no response to an adequate dose and duration of 2 or more antidepressants (i.e., those with treatment-resistant depression or difficult to treat depression). SGAs such as quetiapine, in combination with an antidepressant, may be used as a first-line treatment for MDD that is very severe or has associated psychotic features.
• Quetiapine may reduce symptoms of depression and improve social functioning compared with lithium. However, patients reported more side effects with quetiapine than lithium and viewed the side effects of lithium as more manageable.
• Factors such as patient characteristics, patient tolerability, patient values, side effect profiles of different treatment options, and clinician expertise may also be important to guide choice of treatment for MDD.