Biological treatment (depression)
IB Psychology· Health and well-being· 11 min read
1. Core concept
Biological treatments target the physical basis of a disorder. For depression the main example is antidepressant drugs such as SSRIs (e.g. fluoxetine), which increase serotonin availability at the synapse by blocking its reuptake, aiming to lift mood. They are judged on effectiveness — how far they reduce symptoms compared with a placebo or other treatments, and at what cost in side effects and relapse. Evidence shows they help many patients, but often work best combined with psychological therapy rather than alone.
2. Key studies
IB Psychology answers must be supported by named studies. Learn these to cite as evidence:
TADS (2007)
In the Treatment for Adolescents with Depression Study, fluoxetine, CBT, and their combination were all effective, with the combination giving the fastest short-term response. — Controlled effectiveness evidence for a biological treatment (fluoxetine) — and evidence that the drug alone is not the whole answer.
3. Evaluation (AO3)
Strength — clear target and trial evidence — Drug action gives a testable causal target (serotonin reuptake), and randomised trials such as TADS provide effectiveness evidence at scale.
Limitation — symptoms not causes, and ethics — Drugs treat symptoms rather than causes, carry side effects and relapse risk, and TADS shows combination therapy outperformed medication alone — raising responsibility questions about medicating (especially adolescents).
4. Scope
5. Common Pitfalls
Wrong move:
Describing how an antidepressant works (its mechanism) but not evaluating its effectiveness — or claiming drugs 'cure' depression.
Why:
A frequently penalised misconception in IB Psychology exams.
Correct move:
The KP asks for explanation AND effectiveness: weigh symptom reduction versus placebo, side effects, relapse, and the TADS finding that combination beat medication alone. Drugs manage the disorder, they do not simply cure it.
Going deeper
- Neurotransmissionhow SSRIs act on reuptake is neurotransmission (BIO_9).
- Biological explanation of depressionthe drug targets the biological explanation of depression (HWB_1).
- Psychological treatment (depression)psychological treatment is the comparison and combination arm (HWB_10).