Psychiatry; how much do we really know?

So I have a feeling that a lot of my posts are going to have a common theme and that is this; we do not know a lot of things.

In my experience, it is very common for patients and people in general to think that doctors must know everything and that when we recommend something, that is because we know it works.

Well, I wouldn’t blame you for thinking that because we do often give off that impression.

The truth is that we know very little. In fact, the more we seem to know, the more we realise we knew even less than we thought we did.

Sounds alarming right?

Let me explain…

The human brain is probably one of the most complex things on this planet and we haven’t really scratched the surface in understanding it.

Now, I’m not saying we don’t have a clue what we are talking about, I’m just saying we are far from full understanding of the complexities of what we are treating and how. And if we don’t know exactly what is going on in the brain to cause our symptoms then it follows that we also wouldn’t understand exactly how to treat it.

It’s quite possible that years from now, we will look back and think “what the hell were we thinking?”

Because, although we don’t know a lot, we are learning more and more everyday.

At the Royal College of Psychiatrists International Congress last month, I went to a talk by Professor Thomas Barnes, an expert in schizophrenia and antipsychotics, about the newest updates in guidelines for treatment of schizophrenia.

Well, guess what his take home message was? “It’s all uncertain!”

Interpreting evidence and research is hard. The evidence has to be accurate and reliable. We have to believe that the study is well designed and takes into account other variables that could influence the results. We also have to look at the group of people studied and see whether those people are similar to the people we treat. For example, a study of antidepressant efficacy in elderly people in remote villages in Ecuador is probably unlikely to be relevant to a 16 year old in London.

Then, when we’ve looked at the study, we’ve decided it was well designed, it’s relevant to our population and takes into account other variables, we have another problem.

We now have to take population based data and apply it to an individual person. If a medication cures 60% of people but also causes bad side effects, is it worth it? How can you tell that your patient will be one of the 60% it cures? What if your patient is part of the 40% it doesn’t cure and gives them side effects? What would be the consequences if you didn’t treat your patient? Are there any other medications available?

The truth is we have no way of knowing whether the medication is going to help you individually or not but we do know that if we treat 10 people, 6 will get better. We just don’t know which 6 it will be.

To help us with this we have calculated “number needed to treat”. This is the average number of patients needed to be treated for one person to get a positive outcome but again this doesn’t tell us exactly who will be helped.

In addition, people do not behave in real life in the same way they do in trials. You may have a certain type of person who signs up to the trials or they may be more diligent because they are being observed. Trials also tend to be quite short term as they are expensive and difficult to organise over long periods of time so we often don’t have any evidence for long term treatment.

An example of this was given in Professor Barnes’s talk. The available studies we have on antipsychotic usage are less than 10 years long and most are much shorter follow up than that. We can say quite confidently through meta-analysis of 65 trials that antipsychotic medication reduces relapse risk in patients with schizophrenia for up to 2 years but that very little is known about the long term effects of antipsychotics (Leucht et al 2012). 

Professor Barnes also highlighted that in real world data, it looks like antipsychotic depot (intramuscular injection) medication is effective however, randomised controlled trials suggest they are not.

As you can imagine, this is all a bit confusing and really no one knows what the best treatment is for each patient.

We create guidelines and treat our patients based on the best available evidence but I think it is important that our patients and their families understand that too.

We don’t have all the answers yet, but we are doing the best we can with the information we have.

So next time you are discussing a medication with your doctor, ask them what the evidence is for its efficacy, what is the number needed to treat, how common are the side effects and what the alternatives are.

Then you and your doctor can come to a decision together about what is the best treatment for you at that time and you can feel empowered to be involved in the decision.

 

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