In search of a dose-response relationship in SSRIs-a systematic review, meta-analysis, and network meta-analysis

Area of Science:

• Pharmacology
• Clinical Psychology
• Psychiatry

Background:

• Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed antidepressants.
• Previous dose-response analyses often relied on indirect evidence.
• Direct comparisons of different SSRI dosages are needed to clarify efficacy.

Purpose of the Study:

• To directly compare the antidepressive efficacy of different SSRI doses using randomized controlled trials (RCTs).
• To investigate dose-response relationships for SSRIs as a group and for individual drugs.
• To assess the impact of SSRI dosage on dropout rates.

Main Methods:

• Systematic literature search for relevant RCTs.
• Data extraction and analysis by two independent raters.
• Pairwise random-effects meta-analyses and sensitivity network meta-analyses comparing low, medium, and high SSRI doses.

Main Results:

• Small, clinically non-significant differences in efficacy were observed between SSRI dosage groups.
• Higher SSRI doses were associated with increased dropout rates, primarily due to side effects.
• Specific findings included fluoxetine 60 mg/day being inferior to 20 mg/day, and inconclusive results for paroxetine dosages.

Conclusions:

• No conclusive evidence supports a clinically meaningful dose-response relationship for SSRIs as a group or individually.
• High SSRI doses are not recommended for routine treatment due to lack of proven benefit and increased side effects.
• Further research may be needed for specific drugs and dosages where effects cannot be ruled out.