Some medications will have no impact on counselling ... while other medication may have a huge impact; this impact can range from making it ineffective to making it dangerous. It obviously depends on what the medication is ... what it is being taken for ... and how it is impacting on YOU as an individual. Some people are more susceptible to a particular medication than others and a dosage that has hardly any effect on one person may have a drastic effect on another.
There are two main scenarios that we need to avoid in Online Counselling (and for that matter in any counselling).
The first is an ‘antidepressant’ that is having a strong effect on you. If it is having a strong effect ... then you will not really be bringing yourself to the counselling session ... we will not genuinely be exploring you thoughts and feelings, they will be masked ... the counselling will be ineffective. But then on the other hand a mild antidepressant may have ‘perked’ you up enough that you now feel comfortable confident and ready to explore a long standing issue! (I have counselled many bereaved people taking a moderate antidepressant with no problem).
The second is an anti-psychotic medication. This would possibly be prescribed to someone that is having difficulty keeping in touch with reality and keeping themselves grounded. Online Counselling is not suited for someone experiencing these symptoms and taking this type of medication...
We have the same dilemma with ‘recreational drugs’ and alcohol some people may use them sparingly and it may have no bearing on counselling ... but others may be heavily dependent and this will have an impact on counselling ... so you need to declare these just as much as prescribed drugs.