Everyone is different so the number of sessions required really depends on the person and the issue. For simple problems, some people may feel they have results after a few sessions although four is perhaps the optimum (including consultation). On the other hand, some people may feel they need five to seven sessions to experience the greater benefit. If there are many threads to the issue, then these may all need exploring, although it would be up to you which thread(s) you want to work on according to which you think will bring you the most benefit. Taking a committed approach to the therapy - during and outside of the sessions - will help you to maximise your results.