Absolute frequency analysis within groups

Hi everyone, I need a help with data analysis in SPSS.

I have used a 112 item questionnaire - a Likert scale - with 5 points (strongly agree - strongly disagree).
The questionnaire contains 6 hypothetical categories and each category has around 20 items (questions).

So, what I should do is to group these items into categories and analyse absolute frequencies within groups and display results in a table.
Does anyone have idea how to categorise items into groups? Should I combine different items into one variable and how?