First off, Ritalin is not an antidepressant and should only be used as adjuncts to antidepressants to manage symptoms which are refactory to all other treatments. It is unlikely they will stop the symptoms just cover it up.
If you are getting no benefit from the ritalin you might as well stop it.
ADHD like symptoms can occure in depression. In fact cognitive abnormalities (poor working memory, lack of concentration, easily bored) are some of the key signs.
Both drugs CAN not do produce QT elongation as very rare side effects. It is particually rare in Escitlopram and the effect tends to be limited to the older and young. It is nothing to worry about and the combination is a perfectly safe and often used one.
Taking an SSRI does not make Ritalin more addictive. Taken in clinical doses Ritalin very rarely causes an addiction.
Although it is possible that taking a stimulant long term may actually make depression and anxiety worse.
If you have only been on Escitlopram for 3 weeks, its perfectly reasonable to expect that it would not have had an effect yet. You are expecting a result way to quickly. Antidepressants take time to work. If there has been no positive benefit by week 6 it is worth increasing to the maximum 20mg. You shouldn't disconinue the drug until giving it a trial of 12 weeks. This is a major problem (and reason) for non-response to antidepressants. Proper trials are often not given and people start to try more and more antidepressants in less and less time, with none of them having a chance to work. Antidepressants can take longer than this for a response for OCD. If it isn't working by week twelve then another drug should be tried. Furthermore you are just as likely to paritally respond to an antidepressant as you are to fully remit. In this case psychological therapy and enviromental changes are your best bet. There is also often some benefit to be gained in trying a higher dose or adding in an agumentation agent (not stimulants because there is no evidence for them in depression).
I would strongly recommend you start trying to make some changes in your enviroment and behaviour (behavioual activation, sleep hygeine, reducing stress were possible and practicing mindfulness (has a growing evidence base)). You can further increase your chances of getting better and staying better by adding in psychotherapy. First line psychotherapy should typically be CBT or one two of its many off shoots (ACT, MBCT). There are plenty of books on CBT and its the two off shoots (ACT, mindfulness based cognitive therapy) as there are books on mindfulness as well. Biblio therapy is while not as effective as face to face still very useful. The same can be said for some free online CBT courses. It would be best however if you could access CBT from a qualified professional - often group therapy is slightly more effective and also tends to be cheaper (if you have to pay for it where you live). When looking for a CBT therapist you should look for either postgraduate training in CBT (typically but not always they will come from core mental health profession (psych nurse, OT, soical worker, clinical/councelling psychologist, less commonly a psychiatrist or G.P) or for a clinical or counceling psychologist with experience in CBT.
Edited by Tom_, 27 June 2014 - 10:45 AM.