Administration of ketamine for unipolar and bipolar depression

Objective: Clinical trials demonstrated that ketamine exhibits rapid antidepressant efficacy when administered in subanaesthetic dosages. We reviewed currently available literature investigating efficacy, response rates and safety profile.Methods: Twelve studies investigating unipolar, seven on bipolar depression were included after search in medline, scopus and web of science.Results: Randomized, placebo-controlled or open-label trials reported antidepressant response rates after 24h on primary outcome measures at 61%. The average reduction of Hamilton Depression Rating Scale (HAM-D) was 10.9 points, Beck Depression Inventory (BDI) 15.7 points and Montgomery-Asberg Depression Rating Scale (MADRS) 20.8 points. Ketamine was always superior to placebo. Most common side effects were dizziness, blurred vision, restlessness, nausea/vomiting and headache, which were all reversible. Relapse rates ranged between 60% and 92%. To provide best practice-based information to patients, a consent-form for application and modification in local language is included.Conclusions: Ketamine constitutes a novel, rapid and efficacious treatment option for patients suffering from treatment resistant depression and exhibits rapid and significant anti-suicidal effects. New administration routes might serve as alternative to intravenous regimes for potential usage in outpatient settings. However, long-term side effects are not known and short duration of antidepressant response need ways to prolong ketamine's efficacy.