Behavioral Economics: The Puzzle of Why People Don't Follow Instructions Concerning Their Medicine

I know that it is bad form for Chicago Economist to think about behavioral economic puzzles but I was at the pharmacy the other day and I found a brochure called "Why Must I take my Medicine?" It listed a number of puzzles concerning weird health choices made by people especially by senior citizens:

1. Some people stop taking their medicine especially when they feel good.

2. Some people believe in constant returns to scale in the production of health capital. Regardless of their doctor's orders, they will double their dosage if they believe that a pill is helping them.

One obvious point concerning #1 is that many drugs have nasty short term side effects. for people with hyperbolic preferences, they may choose to shirk in the short run rather than being compliant with their doctor's orders.

Another explanation for #1 is the marginal cost of a pill. For seniors who are poor (such as widows), how do they budget? What tradeoffs are they making?

With respect to #2, there is an under-explored issue of trust. Do patients trust their own judgement or their doctor's judgement? Why does a patient with no medical training believe that he knows best?