TADS (2004) (treatment of adolescents with depression study)

aim

to examine the short-term and long-term effectiveness of drug treatment & psychotherapy

method

longitudinal study

randomized control trial

439 participants who were recruited from 13 clinics in the USA

• the participants were aged 12-17

• they were all diagnosed with major depression

procedure

conducted in 3 stages

Stage 1 - acute treatment (12 weeks)

participants randomly assigned to one of 4 conditions

• fluoxetine alone

• CBT alone

• combo of fluoxetine & CBT

• placebo & clinical management

stage 2 - consolidation treatment (six more weeks)

participants from 4th group were told they were taking a placebo

• could choose any of the other 3 conditions

• couldn’t participate in the study any more

stage 3 - continuation treatment

response rates were used as an indicator of the effectiveness of the treatment

• is the percentage of participants who showed a 50% decrease in the scores on a standardized depression scale (such as the HAM-D)

results

end of stage 1 combo treatment had best response rate (71%)

• response rate of fluoxetine - 61%

• response rate of CBT - 44%

• response rate of placebo - 35%

end of stage 2 - CBT “caught up” with medical treatment (CBT had response rate of 65% & fluoxetine had response rate of 69%)

• response rate of combo treatment - 85%

end of stage 3 - combo treatment was 85%

• response rate was almost 81% for both fluoxetine & CBT

conclusion

all 3 active treatments of depression outperformed placebo - so medical treatment & psychotherapy are effective

effectiveness of antidepressants supports the chemical imbalance theory

in the short-term, medication is more effective than psychotherapy

in the long-term, psychotherapy is more effective

antidepressants should be recommended when an immediate response is needed

strengths

each group separated to a different treatment - isolates the variable of type of treatment, meaning any difference in results between groups can be attributed to the type of treatment

longitudinal study - allows for understanding of short-term & long-term effects of study

large sample size - increases generalizability to Western population

limitation

response rate - some participants may not respond well to the treatment they were assigned to

• improvement - recruit participants diagnosed with MDD, and then separate them into the groups based on their existing treatment

  • if a participant is already receiving antidepressants - put them in fluoxetine group

  • if participant is receiving CBT - put them in CBT group

ethical issues - participants are young & potential side effects of the treatment, could hv impacted them

• could’ve done study with adults

severity of depression could be different between the participants - response rates could be different

low ecological validity & low cross-cultural validity?

implications + applications

shows the effectiveness of CBT & antidepressants

shows strengths of each treatment

informs treatment plans based on treatment outcomes & severity of depression