Why don't we know how antidepressants work yet?

Limits of Current Psychiatric Knowledge

• Several commenters argue we don’t understand the brain well enough for a full theory of how antidepressants work; psychiatry is seen as incomplete but the best available.
• Others note this is common in medicine: many effective drugs (SSRIs, lithium, Tylenol, anesthetics, alcohol) have partially or poorly understood mechanisms.

Efficacy and Individual Variability

• Multiple personal accounts say antidepressants were life‑saving or enabled basic functioning (e.g., agoraphobia, severe depression).
• Others report no benefit, severe side effects, or long‑term complications (e.g., dystonia after Effexor).
• Some stress that “they work” should be understood as “they worked for me”; non‑response and harm are real.
• Treatment‑resistant depression and genetic differences in drug response are mentioned, including tests that predict poor SSRI response for some.

Mechanism, Time Lag, and Theories

• The weeks‑long delay for SSRIs is frequently cited as evidence they act via downstream adaptations, not just “more serotonin.”
• Commenters mention receptor downregulation, changes in brain structure, and neurotrophic factors as hypotheses, but emphasize uncertainty.
• Some question whether “depression” is a single disease rather than a cluster of syndromes with different causes.

Risks, Suicide, and Withdrawal

• Discussion of increased suicide risk early in treatment: motivation may return before mood improves, enabling action on suicidal thoughts.
• Sudden SSRI cessation is described as worsening depression and causing “brain zaps”; tapering is strongly advised.
• Concerns are raised about GP knowledge gaps in psychiatric meds and withdrawal (especially benzodiazepines).
• Benzos and alcohol withdrawal are noted as potentially dangerous or fatal.

Broader Models of Distress

• Distinctions are drawn between biological depression, situational depression/despair, and normal sadness.
• Economic and life stressors are seen as major drivers in some cases, which drugs may not fix.
• Some highlight the gut–brain axis and vagus nerve as emerging but poorly understood contributors.

Pharma, Profit, and Research Priorities

• Commenters argue there is more incentive to sell symptom‑treating drugs and “superfoods” than to fund hard basic science.
• Cheap options like lithium are seen as under‑researched despite strong effects and serious side‑effect profiles (notably kidney risk).