1. psychopathology Evaluation of biochemical factors in depression

2. Any explanation for depression involving a single neurotransmitter such as Norepiniphrine or Serotonin, or a single hormone e.g. Cortisol, is flawed. WHY?

3. The effect of antidepressants Q. How quickly are serotonin levels raised? A. Immediately Q. How long does it take before the effects of antidepressants can be detected? A. Several weeks WHAT DO WE CONCLUDE FROM THIS?

4. How do the drugs work? Possibly by increasing sensitivity of the receiving neurons. This would take more time and would explain the time lag.

5. Individual differences If serotonin and norepeniphrine levels were the only cause of depression everyone would be helped by anti depressant drugs, BUT this is not the case. ALSO Some people with low levels of these neurotransmitters do not get depressed!! EXPLAIN THIS!

6. Cause or effect? Just because drugs that work on serotonin levels reduce depression it is wrong to assume that lack of serotonin is the cause. Why is this?

7. CAUSE OR EFFECT Depression may cause changes in neurotransmitters. Dogs and learned helplessness led to lower levels of norepinephrine. (Miller et al 1977) Martin et al (2001) found that the brains of humans showed changes in serotonin and norephinephrine levels in the basal ganglia (subcortical brain) after interpersonal therapy (learning creates new neuronal connections).

8. Indirect effects Most antidpressant drugs also suppress REM sleep. When deprived of REM sleep symptoms of depression are reduced. (Wu et al 1992) REM deprivation may normalise emotions.