Neurology Center

According to the BBC, the British recession and spending cuts are making us all depressed.


They found that between 2006 and 2010, prescriptions for SSRI antidepressants rose by 43%. They attribute this to a rise in the rates of depression caused by the financial crisis. OK there are a few caveats, but this is the clear message of an article titled Money woes 'linked to rise in depression'. To get this data they used the Freedom of Information Act.

What they don't do is to provide any of the raw data. So we just have to take their word for it. Maybe someone ought to use the Freedom of Information Act to make them tell us? This is important, because while I'll take the BBC's word about the SSRI rise of 43%, they also say that rates of other antidepressants rose - but they don't say which ones, by how much, or anything else. They don't say how many fell, or stayed flat.

Given which it's impossible to know what to make of this. Here are some alternative explanations:

• This just represents the continuation of the well-known trend, seen in the USA and Europe as well as the UK, for increasing antidepressant use. This is my personal best guess and Ben Goldacre points out that rates rose 36% during the boom years of 2000-2005.
  
• Depression has not got more common, it's just that it's more likely to be treated. This overlaps with the first theory. Support for this comes from the fact that suicide rates haven't risen - at least not by anywhere near 40%.
  
• Mental illness is no more likely to be treated, but it's more likely to be treated with antidepressants, as opposed to other drugs. There was, and is, a move to get people off drugs like benzodiazepines, and onto antidepressants. However I suspect this process is largely complete now.
• Total antidepressant use isn't rising but SSRI use is because doctors increasingly prescribe SSRIs over opposed to other drugs. This was another Ben Goldacre suggestion and it is surely a factor although again, I suspect that this process was largely complete by 2007.
  
• People are more likely to be taking multiple different antidepressants, which would manifest as a rise in prescriptions, even if the total number of users stayed constant. Add-on treatment with mirtazapine and others is becoming more popular.
• People are staying on antidepressants for longer meaning more prescriptions. This might not even mean that they're staying ill for longer, it might just mean that doctors are getting better at convincing people to keep taking them by e.g. prescribing drugs with milder side effects, or by referring people for psychotherapy which could increase use by keeping people "in the system" and taking their medication. This is very likely. I previously blogged about a paper showing that in 1993 to 2005, antidepressant prescriptions rose although rates of depression fell, because of a small rise in the number of people taking them for very long periods.
  
• Mental illness rates are rising, but it's not depression: it's anxiety, or something else. Entirely plausible since we know that many people taking antidepressants, in the USA, have no diagnosable depression and even no diagnosable psychiatric disorder at all.
• People are relying on the NHS to prescribe them drugs, as opposed to private doctors, because they can't afford to go private. Private medicine in the UK is only a small sector so this is unlikely to account for much but it's the kind of thing you need to think about.
• Rates of depression have risen, but it's nothing to do with the economy, it's something else which happened between 2007 and 2010: the Premiership of Gordon Brown? The assassination of Benazir Bhutto? The discovery of a 2,100 year old Japanese melon?
  

Paroxetine, aka Paxil aka Seroxat, is an SSRI antidepressant.

Like other SSRIs, its reputation has see-sawed over time. Hailed as miracle drugs in the 1990s and promoted for everything from depression to "separation anxiety" in dogs, they fell from grace over the past decade.

First, concerns emerged over withdrawal symptoms and suicidality especially in young people. Then more recently their antidepressant efficacy came into serious question. Paroxetine has arguably the worst image of all SSRIs, although whether it's much different to the rest is unclear.

Now a new paper claims to provide a definitive assessment of the safety and efficacy of paroxetine in adults (age 18+). The lead authors are from GlaxoSmithKline, who invented paroxetine. So it's no surprise that the text paints GSK and their product in a favourable light, but the data warrant a close look and the results are rather interesting - and complicated.

They took all of the placebo-controlled trials on paroxetine for any psychiatric disorder - because it wasn't just trialled in depression, but also in PTSD, anxiety, and more. They excluded studies with fewer than 30 people; this makes sense though it's somewhat arbitrary, why not 40 or 20? Anyway, they ended up with 61 trials.

First they looked at suicide. In a nutshell paroxetine increased suicidal "behaviour or ideation" in younger patients (age 25 or below) relative to placebo, whether or not they were being treated for depression. In older patients, it only increased suicidality in the depression trials, and the effect was smaller. I've put a red dot where paroxetine was worse than placebo; this doesn't mean the effect was "statistically significant", but the numbers are so small that this is fairly meaningless. Just look at the numbers.

This is not very new. It's been accepted for a while that broadly the same applies when you look at trials of other antidepressants. Whether this causes extra suicides in the real world is a big question.

When it comes to efficacy, however, we find some rather startling info that's not been presented together in one article before, to my knowledge. Here's a graph showing the effect of paroxetine over-and-above placebo in all the different disorders, expressed as a proportion of the improvement seen in the placebo group.

Now I should point out that I just made this measure up. It's not ideal. If the placebo response is very small, then a tiny drug effect will seem large by comparison, even if what this really means is that neither drug nor placebo do any good.

However the flip side of that coin is that it controls for the fact that rating scales for different disorders might be just more likely to show change than others. The d score is a more widely used standardized measure of effect size - though it has its own shortcomings - and I'd like to know those, but the data they provide don't allow us to easily calculate it. You could do it from the GSK database but it would take ages.

Anyway as you can see paroxetine was better, relative to placebo, against PTSD, PMDD, obsessive-compulsive disorder, and social anxiety, than it was against depression measured with the "gold-standard" HAMD scale! In fact the only thing it was worse against was Generalized Anxiety Disorder. Using the alternative MADRS depression scale, the antidepressant effect was bigger, but still small compared to OCD and social anxiety.

This is rather remarkable. Everyone calls paroxetine "an antidepressant", yet at least in one important sense it works better against OCD and social anxiety than it does against depression!

In fact, is paroxetine an antidepressant at all? It works better on MADRS and very poorly on the HAMD; is this because the HAMD is a better scale of depression, and the MADRS actually measures anxiety or OCD symptoms?

That's a lovely neat theory... but in fact the HAMD-17 has two questions about anxiety, scoring 0-4 points each, so you can score up to 8 (or 12 if you count "hypochondriasis", which is basically health anxiety, so you probably should), out of a total maximum of 52. The MADRS has one anxiety item with a max score of 6 on a total of 60. So the HAMD is more "anxious" than the MADRS.

This is more than just a curiosity. Paroxetine's antidepressant effect was tiny in those aged 25 or under on the HAMD - treatment just 9% of the placebo effect - but on the MADRS in the same age group, the benefit was 35%! So what is the HAMD measuring and why is it different to the MADRS?

Honestly, it's hard to tell because the Hamilton scale is so messy. It measures depression and the other distressing symptoms which commonly go along with it. The idea, I think, was that it was meant to be a scale of the patient's overall clinical severity - how seriously they were suffering - rather than a measure of depression per se.

Which is fine. Except that most modern trials carefully exclude anyone with "comorbid" symptoms like anxiety, and on the other hand, recruit people with symptoms quite different to the depressed inpatients that Dr Max Hamilton would have seen when he invented the scale in 1960.

Yet 50 years later the HAMD17, unmodified, is still the standard scale. It's been repeatedly shown to be multi-factorial (it doesn't measure one thing), no-one even agrees on how to interpret it, and a "new scale", the HAMD6, which consists of simply chucking out 11 questions and keeping the 6 that actually measure depression, has been shown to be better. Yet everyone still uses the HAMD17 because everyone else does.

Link: I recently covered a dodgy paper about paroxetine in adolescents with depression; it wasn't included in this analysis because this was about adults.

Carpenter DJ, Fong R, Kraus JE, Davies JT, Moore C, & Thase ME (2011). Meta-analysis of efficacy and treatment-emergent suicidality in adults by psychiatric indication and age subgroup following initiation of paroxetine therapy: a complete set of randomized placebo-controlled trials. The Journal of clinical psychiatry PMID: 21367354

Here at Neuroskeptic fMRI scanning and antidepressants are both big topics.


As I discussed lask week, fish - specifically salmon - are the next big thing in fMRI and the number of salmon brains being scanned is growing at a remarkable rate. But fish haven't made much of an entrance into the world of antidepressants...until now.

Swedish scientists Holmberg et al have just published a paper asking: Does waterborne citalopram affect the aggressive and sexual behaviour of rainbow trout and guppy?

SSRI antidepressants, of which citalopram is one, are very popular. So popular, in fact, that non-trivial levels of SSRIs have been found in sewage and there's a concern that they might make their way into lakes and rivers and thereby affect the behaviour of the animals living there.

Holmberg et al set out to see what citalopram did to some fish in an attempt to find out whether this is likely to be a major problem. So they put some citalopram in the fish's water supplies and then tested their aggressiveness and also their sex drives. It turns out that one of the main ways of measure fish aggression is to put a mirror in their tank and see if they try to fight their own reflection. Fish are not very bright, really.

Anyway, the good news for fish everywhere was that seven days of citalopram exposure had no effect at all, even at doses much higher than those reported as a pollutant (the maximum dose was 0.1 mg/l). And the authors had no conflicts of interest: Big Pharma had nothing to do with this research, although Big Fish Farmer did because they bought the fish from one.

However, this may not be the end of the story, because it turned out that citalopram was very poorly absorbed into the fish's bloodstreams. But other antidepressants have been reported to accumulate in fish. Clearly, the only way to find out for sure what's going on would be to use fMRI...

Holmberg A, Fogel J, Albertsson E, Fick J, Brown JN, Paxéus N, Förlin L, Johnsson JI, & Larsson DG (2011). Does waterborne citalopram affect the aggressive and sexual behaviour of rainbow trout and guppy? Journal of hazardous materials PMID: 21300431

Should a dodgy paper on antidepressants be retracted? And what's scientific retraction for, anyway?


Read all about it in a new article in the BMJ: Rules of Retraction. It's about the efforts of two academics, Jon Jureidini and Leemon McHenry. Their mission - so far unsuccesful - is to get this 2001 paper retracted: Efficacy of paroxetine in the treatment of adolescent major depression.

Jureidini is a member of Healthy Skepticism, a fantastic Australian organization that Neuroskeptic readers have encountered before. They've got lots of detail on the ill-fated "Study 329", including internal drug company documents, here.

So what's the story? Study 329 was a placebo-controlled trial of the SSRI paroxetine (Paxil, Seroxat) in 275 depressed adolescents. The paper concluded: that "Paroxetine is generally well tolerated and effective for major depression in adolescents." It was published in the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP).

There's two issues here: whether paroxetine worked, and whether it was safe. On safety, the paper concluded that "Paroxetine was generally well tolerated...and most adverse effects were not serious." Technically true, but only because there were so many mild side effects.

In fact, 11 patients on paroxetine reported serious adverse events, including suicidal ideation or behaviour, and 7 were hospitalized. Just 2 patients in the placebo group had such events. Yet we are reassured that "Of the 11, only headache (1 patient) was considered by the treating investigator to be related to paroxetine treatment."

The drug company argue that it didn't become clear that paroxetine caused suicidal ideation in adolescents until after the paper was published. In 2002, British authorities reviewed the evidence and said that paroxetine should not be given in this age group.

That's as maybe; the fact remains that in this paper there was a strongly raised risk. However, in fairness, all that data was there in the paper, for readers to draw their own conclusions from. The paper downplays it, but the numbers are there.

Study 329’s results showed that paroxetine was no more effective than the placebo according to measurements of eight outcomes specified by Martin Keller, professor of psychiatry at Brown University, when he first drew up the trial.

Two of these were primary outcomes...the drug also showed no significant effect for the initial six secondary outcome measures. [it] only produced a positive result when four new secondary outcome measures, which were introduced following the initial data analysis, were used... Fifteen other new secondary outcome measures failed to throw up positive results.

Of the depression-related variables, paroxetine separated statistically from placebo at endpoint among four of the parameters: response (i.e., primary outcome measure)...

A new paper has added to the growing ranks of studies finding that antidepressant drugs don't work in people with milder forms of depression: Efficacy of antidepressants and benzodiazepines in minor depression.


It's in the British Journal of Psychiatry and it's a meta-analysis of 6 randomized controlled trials on three different drugs. Antidepressants were no better than placebo in patients with "minor depressive disorder", which is like the better-known Major Depressive Disorder but... well, not as major, because you only need to have 2 symptoms instead of 5 from this list.

They also wanted to find out whether benzodiazepines (like Valium) worked in these people, but there just weren't any good studies out there.

The results look solid, and they fit with the fact that antidepressants don't work in people diagnosed with "major" depression, but who fall at the "milder" end of that range, something which several recent studies have shown. Neuroskeptic readers will, if they've been paying attention, find this entirely unsurprising.

But in fact, it's not just not news, it's positively ancient. 50 years ago, at the dawn of the antidepressant era, it was commonly said that most antidepressants don't work in everyone with "depression", they work best in people with endogenous depression, and less well, or not at all, in those with "neurotic" or "reactive" depressions (see, e.g. 1, 2, 3, but the literature goes back even further).

"Endogenous" is not strictly the same as "severe", however, in practice, these two concepts have never really been clearly seperated, and they're largely equivalent today, because the leading measure of "severity", the Hamilton Scale, measures symptoms, and arguably these symptoms are mostly (though not entirely) the symptoms of the old concept of endogenous depression. The Hamilton Scale was formulated in 1960 when modern concepts of "minor depressive disorder" and "major depressive disorder" were unknown.

Why then are we only now working out that antidepressants only work in some people? There's one obvious answer: Prozac, which arrived in 1987. Before Prozac, antidepressants were serious stuff. They could easily kill you in overdose, and they had a lot of side effects. Many of them even meant that you couldn't eat cheese. As a result, they weren't used lightly.

Prozac and the other SSRIs changed the game completely. They're much less toxic, the side effects are milder, and you can eat as much cheese as you want. So it's very easy to prescribe an SSRI - maybe it won't work, but it can't hurt, so why not try it...?

As a result, I think, the concept of "depression" broadened. Before Prozac, depression was inherently serious, because the treatments were serious. After Prozac, it didn't have to be. Drug company marketing no doubt helped this process along, but marketing has to have something to work with. Over the past 25 years, terms like "endogenous", "neurotic" etc. largely disappeared from the literature, replaced by the single construct of "Major Depression".

For nearly 1,000 years, the great scientific and philosophical work of the ancient Greeks and Romans were lost to Europeans. Only when Christian scholars rediscovered them in the libraries of the Islamic world did Europe begin to remember what it had forgotten. We call those the Dark Ages. Will the past 25 years be remembered as psychiatry's Dark Age?

Barbui, C., Cipriani, A., Patel, V., Ayuso-Mateos, J., & van Ommeren, M. (2011). Efficacy of antidepressants and benzodiazepines in minor depression: systematic review and meta-analysis The British Journal of Psychiatry, 198 (1), 11-16 DOI: 10.1192/bjp.bp.109.076448

A paper just out reports on the changing patterns of treatment for depression in the USA, over the period from 1998 to 2007.

The headline news is that it increased: the overall rate of people treated for some form of "depression" went from 2.37% to 2.88% per year. That's an increase of 21%, which is not trivial, but it's much less than the increase in the previous decade: it was just 0.73% in 1987.

But the increase was concentrated in. some groups of people.

• Americans over 50 accounted for the bulk of the rise. Their use went up by about 50%, while rates in younger people stayed almost steady. In '98 the peak age band was 35-49, now it's 50-64, with almost 5% of those people getting treated in any given year.
  
• Men's rates of treatment went up by over 40% while women's only increased by 10%. Women are still more likely to get treated for depression than men, though, with a ratio of 1.7 women for each 1 man. But that ratio is a lot closer than it used to be.
  
• Black people's rates increased hugely, by 120%. Rates in black people now stand at 2.2% which is close behind whites at 3.2%. Hispanics are now the least treated major ethnic group at 1.9%: in previous studies, blacks were the least treated. (There was no data on Asians or others).
  

What's the best way to overcome depression? Antidepressant drugs, or Buddhist meditation?

A new trial has examined this question: Segal et al. The short answer is that 8 weeks of mindfulness mediation training was just as good as prolonged antidepressant treatment over 18 months. But like all clinical trials, there are some catches.

Right mindfulness, sammā-sati, is the 7th step on the Buddha's Nobel Eightfold Path of enlightenment. In its modern therapeutic form, however, it's a secular practice: you don't have to be a Buddhist to meditate here (but it presumably helps).

Mindfulness meditation is also branded nowadays as mindfulness-based cognitive behavioural therapy (MCBT), although how much it has in common with regular CBT is debatable. The technique is derived from the Buddhist tradition.

The essence of mindfulness is deceptively simple: you try to become a detached observer of your own feelings and thoughts. Rather than just getting angry, you notice the feelings of anger, without letting them take over. As I've written before, while this might sound easy, we're not always aware of our own feelings.

MCBT has attracted a lot of attention as a possible way of helping people with depression achieve relapse prevention. The idea is that if you can train people to become aware of depressive thoughts and feelings if they start to reappear, they'll be able to avoid being sucked into the cycle of depression.

The 160 patients in this trial were initially treated with antidepressants, starting with an SSRI, and if that didn't work, moving onto venlafaxine (up to 375 mg, as necessary, which is a serious dose) or mirtazapine for people who couldn't take the side effects. This is a sensible treatment regime, not one relying on low doses and doubtful drugs, as in many other antidepressant trials.

About half of the patients both stayed in the trial and achieved remission. After 5 months of sustained treatment, these 84 patients were randomized into 3 groups: continuation of their antidepressant, placebo pills, or mindfulness. The people who ended up on placebo had their antidepressants gradually replaced by sugar pills over a number of weeks, to avoid withdrawal effects.

Here's what happened:

People on placebo did very badly, with only 20% remaining well 18 months later. People who either stayed on the drugs, or who got the mindfulness training, did a lot better, with 70% staying well, and there were no differences between the two.

However here's the catch. This was only true of a sub-set of the patients, the ones who had an "unstable remission", meaning that when they were originally treated with drugs, their symptoms went up and down a bit. The "stable remission" people showed no benefits of either treatment, with the ones on placebo doing slightly better, if anything.

Overall, though, this is a decent study, and shows that, for some people, mindfulness can be helpful. A skeptic could complain that mindfulness was no better than medication, but it might have two advantages: cost, and side effects, though this would depend on the medication you were talking about (some are a lot more expensive, and more prone to side-effects, than others.) The mindfulness meditation also wasn't double-blind, so the benefits may have been placebo effects, but that could be said of almost any trial of psychotherapy.

I also wonder whether you'd do even better if you became all mindful and stayed on medication: this study had no combined-treatment group, unfortunately, but this is something to look into...

Segal ZV, Bieling P, Young T, Macqueen G, Cooke R, Martin L, Bloch R, & Levitan RD (2010). Antidepressant Monotherapy vs Sequential Pharmacotherapy and Mindfulness-Based Cognitive Therapy, or Placebo, for Relapse Prophylaxis in Recurrent Depression. Archives of general psychiatry, 67 (12), 1256-64 PMID: 21135325

Some ideas seem so nice, so inoffensive and so harmless, that it seems a shame to criticize them.

Crucially, however, the same was not true of physical exercise which was part of your job. That didn't help at all, and indeed the most strenuous jobs were associated with more depression (but less anxiety, strangely).

How does this fit with the very popular idea that exercise helps in depression? Well, many randomized trials have indeed shown exercise to be better than not-exercize for depression, but the problem is that these trials are never really placebo controlled. You can usually tell whether or not you're going jogging in the park every morning.

So the direct effects of exercise per se are hard to distinguish from the social and psychological meaning of "exercise". Knowing that you're starting a program of exercise could make you feel better: you're taking positive action to improve your life, you're not helpless in the face of your problems. By contrast, doing heavy work as part of your job, while physiologically beneficial, is unlikely to be so much fun.

This doesn't mean that telling people to get more exercise isn't a good idea, but if the meaning of exercise is more important than the physiology, that has some big implications for how it ought to be used.

It's good news for people who just can't take part in strenuous physical exercise because of physical illness or disability, something which is quite common in mental health. It suggests that these people could still get the benefits attributed to exercise even if they did less demanding forms of meaningful activity.

But it's bad news for doctors tempted to default to "get out and go jogging" whenever they see a potentially depressed person. Because if it's the meaning of exercise that counts, and you recommend exercise in a way which sounds like you're dismissing their problems, the meaning will be anything but helpful.

In clinical trials of exercise, the exercise program has, almost by definition, a positive value: it's the whole point of the trial. And the participants just wouldn't have volunteered for the trial if they didn't, on some level, think it would make them feel better.

But not everyone thinks that way. If you go to your doctor looking to get medication, or psychotherapy, or something like that, and you're told that all you need to do is go and get more exercise, it would be easy to see that as a brush-off, especially if it's done unsympathetically. The point is, if exercise doesn't feel like a positive step, it probably won't be one.

Harvey SB, Hotopf M, Overland S, & Mykletun A (2010). Physical activity and common mental disorders. The British journal of psychiatry : the journal of mental science, 197, 357-64 PMID: 21037212

Recently, I wrote about diurnal mood variation: the way in which depression often waxes and wanes over the course of the day. Mornings are generally the worst.

A related phenomenon is late insomnia, or "early morning waking".

But this phrase is rather an understatement. Everyone's woken up early. Maybe you had a flight to catch. Or you were drunk and threw up. Or you just needed a pee. That's early morning waking, but not the depressive kind. When you're depressed, the waking up is the least of your problems.

Suddenly, you are awake, more awake than you've ever been. And you know something terrible has happened, or is about to happen, or that you've done something terribly wrong. It feels like a Eureka moment. You can be a level-headed person, not given to jumping to conclusions, but you will be convinced of this.

In a panic attack, you think you're going to die. Your heart is beating too fast, your breathing's too deep: your body is exploding, you can feel it too closely. With this, With this, you think you should die or even, in some sense, already have. It feels cold: you can no longer feel the warmth of your own body.

The moment passes; the terrible truth that you were so certain of five minutes ago becomes a little doubtful. Maybe it's not quite so bad. At this point, the wakefulness goes too, and you become, well, as tired as you ought to be at 3 am. You try to go back to sleep. If you're lucky, you succeed. If not, you lie awake until morning in a state of miserable contemplation.

While it's happening, you think that you're going to feel this way forever; bizarrely, you think you always have felt this way. In fact, this is the darkest hour.

*

Why does this happen? There has been almost no research on early morning waking. Presumably, because it's so hard to study. To observe it, you would have to get your depressed patients to spend all night in your brain scanner (or, if you prefer, on your analyst's couch), and even then, it doesn't happen every night.

But here's my theory: the key is the biology of sleep. There are many stages of sleep; at a very rough approximation there's dreaming REM, and dreamless slow-wave. Now, REM sleep tends to happen during the second half of the night - the early morning.

During REM sleep, the brain is, in many respects, awake. This is presumably what allows us to have concious dreams. Whereas in slow wave sleep, the brain really is offline; slow waves are also seen in the brain of people in comas, or under deep anaesthesia.

When we're awake, the brain is awash with modulatory neurotransmitters, such as serotonin, norepinephrine, and acetylcholine. During REM, acetylcholine is present, while in slow-wave sleep it's not; indeed acetylcholine may well be what stops slow waves and "wakes up" the cortex.

But unlike during waking, serotonin and norepinephrine neurons are entirely inactive during REM sleep - and only during REM sleep. This fact is surprisingly little-known, but it seems to me that it explains an awful lot.

For one thing, it explains why drugs which increase serotonin levels, such as SSRI antidepressants, inhibit REM sleep. Indeed, high doses of MAOi antidepressants prevent REM entirely (without any noticeable ill-effects, suggesting REM is dispensable). SSRIs only partially suppress it.

Ironically, SSRIs can make dreams more vivid and colourful. I've been told by sleep scientists that this is because they delay the onset of REM so the dreams are "shifted" later into the night making you more likely to remember them when you wake up. But there could be more to it than that.

The fact that REM is a serotonin-free zone also explains wet dreams. Serotonin is well known to suppresses ejaculation; that's why SSRIs delay orgasm, one of their least popular side effects, although it's useful to treat premature ejaculation: every cloud has a silver lining.

So, having said all that: could this also explain the terror of early-morning waking? Suppose that, for whatever reason, you woke up during REM sleep, but your serotonin cells didn't wake up quick enough, leaving you awake, but with no serotonin (a situation which never normally occurs, remember). How would that feel?

Using a technique called acute tryptophan depletion (ATD), you can lower someone's serotonin levels. In most people, this doesn't do very much, but in some people with a history of depression, it causes them to relapse. Here's what happened to one patient after ATD:

[her] previous episodes of clinical depression were associated with the loss of important friendships had, while depressed, been preoccupied with fears that she would never be able to sustain a relationship. She had not had such fears since then.

She had been fully recovered and had not taken any medication for over a year. About 2 h after drinking the tryptophan-free mixture she experienced a sudden onset of sadness, despair, and uncontrollable crying. She feared that a current important relationship would end.

We don't know why tryptophan depletion does this to some people, or why it doesn't affect everyone the same way, and it's pure speculation that early morning waking has anything to do with this. But having said that, the pieces do seem to fit.

Electroconvulsive therapy (ECT) is the oldest treatment in psychiatry that's still in use today. ECT uses a brief electrical current to induce a generalized seizure. No-one knows why, but in many cases this rapidly alleviates depression - amongst other things.

The problem with ECT is that it may cause memory loss. It's hotly debated how serious of a problem this is, and most psychiatrists agree that the risk is justified if the alternative is untreatable illness, but it's fair to say that whether or not it's not as bad as some people believe, the fear that it might be, is the main limitation to the use of the treatment.

Wouldn't it be handy if there was a way of getting the benefits of ECT without the risk of side effects? To that end, people have tried tinkering with the specifics of the electrical stimulation - the frequency and waveform of the current, the location of the electrodes, etc. - but unfortunately it seems like the settings that work best, tend to be the ones with the most side effects.

Enter magnetic seizure therapy (MST). As the name suggests, this is like ECT, except it uses powerful magnets, instead of electrical current, to cause the seizures. In fact though, the magnets work by creating electrical currents in the brain by electromagnetic induction, so it's not entirely different.

MST is thought to be more selective than ECT, in that it induces seizures in the surface of the brain - the cerebral cortex - but not the hippocampus, and other structures buried deeper in the brain, which are involved in memory.

It was first proposed in 2001, and since then it's been tested in a number of very small trials in monkeys and people. Now a group of German psychiatrists say that it's as effective as ECT, but with fewer side effects, in a new trial of 20 severely depressed people. Ironically, they work on Sigmund Freud Street, Bonn. I am not sure what Freud would say about this.

The trial was randomized, but not blinded: it's hard to blind people to this because the equipment used looks completely different. Nor was there a placebo group. All the patients had failed to improve with multiple antidepressants, and psychotherapy in almost all cases, and were therefore eligible for ECT. If anything, the MST group were slightly more ill than the ECT group at baseline.

The ECT they used was right unilateral. This is probably not quite as effective as stimulation which targets both sides of the brain (bitemporal or bifrontal), but has fewer side-effects.

So what happened? After 12 sessions, MST and ECT both seemed to work, and they were equally effective on average. Some patients got much better, some only got a bit better.

What about side effects? MST was noticeably "gentler", in that it didn't cause headaches or muscle pain, and people recovered from the seizures much faster (2 minutes vs 8 minutes to reorientation) after MST. This may have been because the seizures (as assessed using EEG) were less intense.

In terms of the all-important memory and cognitive side effects, however, it's not clear what was going on. They used a whole bunch of neuropsychological tests. In some of them, people got worse over the course of the sessions. In others, they got better. But in several, the scores went up and down with no meaningful pattern. If anything the MST group seemed to do a bit better but to be honest it's impossible to tell because there's so much data and it's so messy.

Unfortunately the tests they used have been criticized for not picking up the kinds of memory problems that some ECT patients complain of e.g. the "wiping" of old memories. For some reason they didn't just ask people whether they felt their memory was damaged or not.

Overall, this trial confirms that MST is a promising idea, but it remains to be seen whether it has any meaningful advantages over old school shock therapy...

Kayser S, Bewernick BH, Grubert C, Hadrysiewicz BL, Axmacher N, & Schlaepfer TE (2010). Antidepressant effects, of magnetic seizure therapy and electroconvulsive therapy, in treatment-resistant depression. Journal of psychiatric research PMID: 20951997

Reboxetine is an antidepressant. Except it's not, because it doesn't treat depression.

This is the conclusion of a much-publicized article just out in the BMJ: Reboxetine for acute treatment of major depression: systematic review and meta-analysis of published and unpublished placebo and SSRI controlled trials.

Reboxetine was introduced to some fanfare, because its mechanism of action is unique - it's a selective norepinephrine reuptake inhibitor (NRI), which has no effect on serotonin, unlike Prozac and other newer antidepressants. Several older tricyclic antidepressants were NRIs, but they weren't selective because they also blocked a shed-load of receptors.

So in theory reboxetine treats depression while avoiding the side effects of other drugs, but last year, Cipriani et al in a headline-grabbing meta-analysis concluded that in fact it's the exact opposite: reboxetine was the least effective new antidepressant, and was also one of the worst in terms of side effects. Oh dear.

And that was only based on the published data. It turns out that Pfizer, the manufacturers of reboxetine, had chosen to not publish the results of most of their clinical trials of the drug, because the data showed that it was crap.

The new BMJ paper includes these unpublished results - it took an inordinate amount of time and pressure to make Pfizer agree to share them, but they eventually did - and we learn that reboxetine is:

• no more effective than a placebo at treating depression.
• less effective than SSRIs, which incidentally are better than placebo in this dataset (a bit).
• worse tolerated than most SSRIs, and much worse tolerated than placebo.
  

People who quit antidepressants slowly, by gradually decreasing the dose, are much less likely to suffer a relapse, according to Baldessarini et al. in the American Journal of Psychiatry.

They describe a large sample (400) of patients from Sardinia, Italy, who had responded well to antidepressants, and then stopped taking them. The antidepressants had been prescribed for either depression, or panic attacks.

People who quit suddenly (over 1-7 days) were more likely to relapse, and relapsed sooner, than the ones who stopped gradually (over a period of 2 weeks or more).

This graph shows what % of the patients in each group remained well at each time point (in terms of days since their final pill.) As you can see, the two lines separate early, and then remain apart by about the same distance (20%) for the whole 12 months.

What this means is that rapid discontinuation didn't just accelerate relapses that were "going to happen anyway". It actually caused more relapses - about 1 in 5 "extra" people. These "extra" relapses all happened in the first 3 months, because after that, the slope of the lines is identical.

On the other hand, they rarely happened immediately - it's not as if people relapsed within days of their last pill. The pattern was broadly similar for older antidepressants (tricyclics) and newer ones (SSRIs).

The authors note that these data throw up important questions about "relapse prevention" trials comparing people who stay on antidepressants vs. those who are switched - abruptly - to placebo. People who stay on the drug usually do better, but is this because the drug works, or because the people on placebo were withdrawn too fast?

This was an observational study, not an experiment. There was no randomization. People quit antidepressants for various "personal or clinical reasons"; 80% of the time it was their own decision, and only 20% of the time was it due to their doctor's advice.

So it's possible that there was some underlying difference between the two groups, that could explain the differences. Regression analysis revealed that the results weren't due to differences in dose, duration of treatment, diagnosis, age etc., but you can't measure every possible confound.

Only randomized controlled trials could provide a final answer, but there's little chance of anyone doing one. Drug companies are unlikely to fund a study about how to stop using their products. So we have only observational data to go on. These data fit in with previous studies showing that there's a similar story when it comes to quitting lithium and antipsychotics. Gradual is better.

But that's common sense. Tapering medications slowly is a good idea in general, because it gives your system more time to adapt. Of course, sometimes there are overriding medical reasons to quit quickly, but apart from in such cases, I'd always want to come off anything as gradually as possible.

Baldessarini RJ, Tondo L, Ghiani C, & Lepri B (2010). Illness risk following rapid versus gradual discontinuation of antidepressants. The American journal of psychiatry, 167 (8), 934-41 PMID: 20478876

There's a paradox at the heart of modern psychiatry, according to an important new paper by Dr Charles E. Dean, Psychopharmacology: A house divided.

It's a long and slightly rambling article, but Dean's central point is pretty simple. The medical/biological model of psychiatry assumes that there are such things as psychiatric diseases. Something biological goes wrong, presumably in the brain, and this causes certain symptoms. Different pathologies cause different symptoms - in other words, there is specificity in the relationship between brain dysfunction and mental illness.

Psychiatric diagnosis rests on this assumption. If and only if we can use a given patient's symptoms to infer what kind of underlying illness they have (schizophrenia, bipolar disorder, depression), diagnosis makes sense. This is why we have DSM-IV which consists of a long list of disorders, and the symptoms they cause. Soon we'll have DSM-V.

The medical model has been criticized and defended at great length, but Dean doesn't do either. He simply notes that modern psychiatry has in practice mostly abandoned the medical model, and the irony is, it's done this because of medicines.

If there are distinct psychiatric disorders, there ought to be drugs that treat them specifically. So if depression is a brain disease, say, and schizophrenia is another, there ought to be drugs that only work on depression, and have no effect on schizophrenia (or even make it worse.) And vice versa.

But, increasingly, psychiatric drugs are being prescribed for multiple different disorders. Antidepressants are used in depression, but also all kinds of anxiety disorders (panic, social anxiety, general anxiety), obsessive-compulsive disorder, PTSD, and more. Antipsychotics are also used in mania and hypomania, in kids with behaviour problems, and increasingly in depression, leading some to complain that the term "antipsychotics" is misleading. And so on.

So, Dean argues, in clinical practice, psychiatrists don't respect the medical model - yet that model is their theoretical justification for using psychiatric drugs in the first place.

He looks in detail at one particularly curious case: the use of atypical antipsychotics in depression. Atypicals, like quetiapine (Seroquel) and olanzapine (Zyprexa), were originally developed to treat schizophrenia and other psychotic states. They are reasonably effective, though most of them are no more so than older "typical" antipsychotics.

Recently, atypicals have become very popular for other indications, most of all mood disorders: mania and depression. Their use in mania is perhaps not so surprising, because severe mania has much in common with psychosis. Their use in depression, however, throws up many paradoxes (above and beyond how one drug could treat both mania and its exact opposite, depression.)

Antipsychotics block dopamine D2 receptors. Psychosis is generally considered to be a disorder of "too much dopamine", so that makes sense. The dopamine hypothesis of psychosis and antipsychotic action is 50 years old, and still the best explanation going.

But depression is widely considered to involve too little dopamine, and there is lots of evidence that almost all antidepressants (indirectly) increase dopamine release. Wouldn't that mean that antidepressants could cause psychosis (they don't?). And why, Dean asks, would atypicals, that block dopamine, help treat depression?

Maybe it's because they also act on other systems? On top of being D2 antagonists, atypicals are also serotonin 5HT2A/C receptor blockers. Long-term use of antidepressants reduces 5HT2 levels, and some antidepressants are also 5HT2 antagonists, so this fits. However, it creates a paradox for the many people who believe that 5HT2 antagonism is important for the antipsychotic effect of atypicals as well - if that were true, antidepressants should be antipsychotics as well (they're not.) And so on.

There may be perfectly sensible answers. Maybe atypicals treat depression by some mechanism that we don't understand yet, a mechanism which is not inconsistent with their also treating psychosis. The point is that there are many such questions standing in need of answers, yet psychopharmacologists almost never address them. Dean concludes:

it seems increasingly obvious that clinicians are actually operating from a dimensional paradigm, and not from the classic paradigm based on specificity of disease or drug... the disjunction between those paradigms and our approach to treatment needs to be recognized and investigated... Bench scientists need to be more familiar with current clinical studies, and stop using outmoded clinical research as a basis for drawing conclusions about the relevance of neurochemical processes to drug efficacy. Bench and clinical scientists need to fully address the question of whether the molecular/cellular/anatomical findings, even if interesting and novel, have anything to do with clinical outcome.