# Learn by Doing ( I give you example for solution )

I’m working on a Mathematics question and need guidance to help me study.

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

During the 1980’s the federal government, through the National Institutes of Health (NIH), sponsored a large clinical trial to evaluate 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 treatment groups and followed them for 2-4 years to track any recurrences of depression.
(Prien et al., Archives of General Psychiatry, 1984).

### Summary statistics for AcuteT:

Group by: Treat

Treat n Mean Variance Std. dev. Std. err. Median Range Min Max Q1 Q3
0 37 172.62162 6446.7973 80.29195 13.199915 173 393 48 441 114 211
1 38 183.65789 6782.1771 82.353974 13.359579 166.5 381 47 428 131 212
2 34 202.11765 10590.168 102.90854 17.648669 163.5 442 70 512 140 246

### 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

example for soultion at the word file