Any activity which is made habitual and which forms a psychological focus is likely to become 'addictive' in the sense that withdrawing from the activity will cause stress.

The Holy Name technique - for non initiates - this is the one that involves concentrating on the breath - something which invariably leads to a slowing of respiration and of the breathing becoming more shallow or overly deep - the effect is to induce mild anoxia or hypoxia. An experience of euphoria may follow.

In addition to anoxia/hypoxia various neuro chemicals undergo change in prolonged meditation and certain mental states are induced - these are frequently accompanied by a withdrawl from emotional engagement with other people and from the world in general. For someone who has made this type of meditation a constant feature of the life  engaging with people while not having recourse to the anaesthetic of meditation can be very painful.

Anyone who can not voluntarily go without their meditation hit should recognise that they have an addiction.