SCIENCE, SLEEP AND SSRIs

In an earlier post, I mentioned that I have narcolepsy with cataplexy, which is a very odd condition, and becomes odder all the time. One of the recent discoveries about it involves the identification of orexin producing cells in the hypothalamus, and their depletion in narcolepsy. Hence there is a diagnostic test which involves a lumbar puncture to take a sample of cerebro-spinal fluid and analyse it for orexin concentration. In narcoleptics, the level is either abnormally low, or undetectable.

I was very worried about having the test. Notwithstanding the unpleasantness of the test itself, it has taken me more than half my life to find a sympathetic neurologist who would agree that my symptoms might be narcolepsy with cataplexy, and the diagnostic validity of this test is taken to be so strong that I was terrified the outcome. What if the orexin count was not low? It would leave me wondering if my symptoms were psychiatric all along, and perhaps my neurologist would think that too.

Photograph by MegElizabeth

Anyway, I needn't have worried. I was honest with my neurologist about my apprehension, and he said that whatever the outcome, he felt strongly that something neurological was going on, and that nothing would alter his standard of care to me. You can see why I didn't want to lose him! As it turned out, my orexin levels were, as he put it, "barn door abnormal".

I take modafinil for the narcolepsy, and venlafaxine for cataplexy at the moment, although I used to take prozac for the latter. Over at Ben Goldacre's brilliant Bad Science blog, there's a discussion going on about the quality of research into the effectiveness of selective seratonin re-uptake inhibitors, SSRIs, like prozac. Most particular to the confusion as to their effectiveness seems to be the selective reporting of positive trials, and mis-reporting of some that had less favourable results. Venlafaxine is a selective seratonin-norepinephrine reuptake inhibitor (SNRI), and I don't know how well its trials and their fair publication compare.

One thing that is always interesting about psychoactive drugs is that there are high variations from individual to individual in their effect, dosage and efficacy. They also seem to act differently for different conditions. For example, fluoxetine (prozac), when prescribed for depression, usually takes a couple of weeks to start taking effect. When I was prescribed it for cataplexy, the effect was within 48 hours. It seems to me that it must be acting through different channels in each case. The human nervous system is an enigmatic and complex machine, and I don't think our current understanding is adequate to explain these differences. It is interesting, for instance that Parkinson's patients can develop secondary narcolepsy, and exhibit the full range of narcolepsy and cataplexy symptoms, although the primary defect is in the dopamine system. Recent research has seemed to indicate that REM sleep behaviour disorder (RBD) is strongly associated with later development of Parkinson's Disease, unless it is associated with narcolepsy, in which such a progression is not expected.

It all makes me wonder whether depression is really a single illness at all, when it has many different triggers (and none) and manifests itself differently from person to person in its extent, prognosis and response to treatment. When the brain and its workings are so difficult to understand, then any medical trial has the problem that even in the patient group, we may not be comparing like with like. Faced with the difficulties in trials of comparing an active drug accurately with placebo, and the added difficulty of comparing placebo to no treatment at all, the possibility that very similar symptoms may arise from different organic mechanisms within the study group makes any inferences very tricky indeed.

I'm not arguing against trials - on the contrary, I think we need to know far more. But we also need to better understand the nature and origin of the illnesses before we can make hard pronouncements. We need well organised, well reported trials, but we also need to be willing to challenge all underlying assumptions openly and honestly, and not censor or prejudice any possible debate.

LACK OF SLEEP IS A LOT LIKE MENTAL ILLNESS

I was amazed to read this report in the 26th October edition of NewScientist. Not because it was news to me, but because I am constantly surprised that it should be news to anybody else. Matthew Walker of the University of California, Berkeley, concluded that, "It is thought that psychiatric conditions create sleep problems. We should entertain the possibility that it is a sleep disorder that is creating the condition."

As a sufferer of narcolepsy with cataplexy, I am only too well aware of the confusions that arise in diagnosis. My symptoms began when I was about 13 or 14, but I did not receive the correct diagnosis until I was 36. This is not unusual, and unfortunately my experience of referrals to psychiatrists for many years is not uncommon either.

In some ways I sympathise with general practitioners: narcolepsy is underdiagnosed and misunderstood. Although it is recognised as a neurological, degenerative condition, the diagnostic criteria to which physicians refer are still to be found in DSM IV, the primary diagnostic reference for psychiatric and psychological disorders. In one, large-scale study, the average delay between symptom onset and diagnosis was 17 years. Other papers available in the academic literature have documented case studies of confusion in diagnosis that have ended up with narcoleptics diagnosed wrongly with schizophrenia or adult ADHD.

My sympathy runs out, though, when the failure is not in the medics' available resources, but in their ability to listen without prejudice. I eventually found out my own diagnosis through the wonderful world wide web, but getting a GP to agree, accept and treat my condition was another matter. After several changes of GP, I finally found one who was prepared to give me the benefit of the doubt, read all my medical records and see that the evidence was there. Referral to a similarly open-minded local neurologist led to the test results that finally confirmed the diagnosis.

Since having the correct diagnosis and treatment, my life has changed immeasurably for the better. I have endless gratitude for the GP who finally listened. She calls it "simply doing her job". Not all do, and this is disadvantages the physicians as well as their patients, who can be a vast resource of anecdotal information that could inspire further lines of research.