MATH 160 Cuyamaca College Treating Depression Discussion

Clinical depression is a recurrent illness requiring treatment andoften hospitalization. Nearly 50% of people who have an episode of majordepression will have a recurrence within 2-3 years. Being able toprevent the recurrence of depression in people who are at risk for thedisease would go a long way to alleviate the pain and suffering ofpatients.

During the 1980’s the federal government, through theNational Institutes of Health (NIH), sponsored a large clinical trial toevaluate two drugs for depression. There were 3 treatment groups.Patients received either Imipramine (Imip), Lithium (Li), or a Placebo(Pl). Researchers randomly assigned patients to one of the 3 treatmentgroups and followed them for 2-4 years to track any recurrences ofdepression.
(Prien et al., Archives of General Psychiatry, 1984).

Variables

• Hospt: Which hospital the patient was from: Labeled 1, 2, 3, 5 or 6
• Treat: 0=Lithium; 1=Imipramine; 2=Placebo
• Outcome: 0=Success 1=Failure (recurrence of depression)
• Time: Number of weeks until a recurrence (if outcome=1) or until study ended (if outcome=0)
• AcuteT: How long the patient was depressed before the start of the current study, measured in days
• Age: Age in years
• Gender: 1=Female 2=Male

Data

If you have not done so already, download the depression datafile (as always, if a login box opens, just close it and then download the file). Then upload the file in StatCrunch.

Prompt

We will analyze the data to answer the second research question: Which of the drugs (if either) delayed the recurrence of depression longer relative to the placebo?

In the previous lab-preparation activity, we identified Treat as the explanatory variable and Timeas the response variable. We also determined that we will analyze thedata using side-by-side boxplots and descriptive statistics (i.e.5-number summaries since the graphs are boxplots).

1. Make graphs and tables.
   1. Use StatCrunch to produce side-by-side boxplots. (directions)
      Embed your graphs with your initial post.
   2. Use StatCrunch to produce the descriptive statistics (a table containing the 5-number summaries for each comparison group). (directions)
      Copy and paste the StatCrunch output table into your initial post.
2. Analyze the data:Compare the distributions for the treatment groups as demonstrated inUnit 2. For example, compare medians and intervals of typical values.Describe the shape and any outliers. Be sure to write your comparisonsso the reader can understand the context of the numbers. For example,don’t just say the median is 30; instead, say something like this: on average patients taking the placebo relapsed in 30 days (Q2=30 days).
3. Draw a conclusion:What can we conclude from your analysis? Did one drug successfullydelay a relapse of depression better than the others? What evidencesupports your conclusion?
4. Summarize your conclusions in response to both research questions:In this lab you compared three treatments (two drugs and the placebo)using two different variables. In Part 1 you compared whether or not arelapse into depression occurred for each of the two drugs and theplacebo. In Part 2 you compared the length of time until the nextrelapse for the two drugs and the placebo. What can you conclude inlight of both analyses? Is one treatment better than the other? How doesthe data support your conclusion?