'Discuss' questions are normally worth either 12 or 24 marks. An example may be 'Discuss neural mechanisms in aggression'. Disuss questions should always start with describing something e.g. in this case, you would start by giving a brief overview (description) of the role of serotonin and the amygdala in aggression. This is to gain AO1 marks (normally worth either 2 or 4 marks and are the easiest to gain if you 'know your stuff!').
Next, you would provide evidence in support (e.g. of the role of serotonin/amygdala by stating research findings and studies) and then either evidence against (studies which did not find this evidence) or criticisms of the evidence in support (e.g. reliability/validity issues of the studies in support). This is to gain AO2 marks and you would repeat this process if it was a 24 mark question.
Finally, the IDA (Issues/Debates/Approaches) section. Here, you develop one or more points relating to the discussion point e.g. the neural mechanisms explanation of aggression. For example, reductionism (a CRITICISM is that this is a simplistic explanation for a complex phenomenon, but an ADVANTAGE is that this allows for the benefits of focusing on one particular explanation) e.g. focusing on biological/neural explanations of aggression ignores possible environmental influences, but allows for medication to be targeted towards one specific thing.
