Kaleidoscope June 2017
Kaleidoscope Column in the BJPsych
July’s Kaleidoscope column in the British Journal of
Psychiatry asks what’s the deal with red hair. Well,
sort of. More precisely it looks at the phenomenon of
epistasis. If genes didn’t interact with each other, and
they all acted independently, mutation rates would increase - and
evolutionary fitness decrease - at an exponential rate. However,
genes do impact each other – which is the process known as
epistasis. Hair colour is the classic teaching example: analogous
to skin complexion, ever greater quantities of the pigment
eumelanin creates blonde, brown, and black hair successively.
Except in one group… they have a variant in a different
gene that impacts this by preventing the conversion of pheomelanin
to eumelanin: they are the red heads. There is a proper point to
this beyond being interesting pop-science nugget, and Kaleidoscope
discusses a paper from Science that explains how humans
are subject to synergistic epistasis, which helps remove
deleterious alleles from the population. It does not infer that
having red hair should be viewed as a mutation.
Long-term effects of antipsychotics is a hot-button
issue. We already know that those with psychoses face a
considerable loss of average life-expectancy – do medications add
to this?Two major potential pathological processes have
been proposed. One is dopamine sensitization: use of medication
purportedly creating a vicious cycle of changes to receptors that
can only be managed by on-going antipsychotic treatment. The second
is of medication-induced reductions in brain volume, a possible
direct neurotoxic effect that has the obvious potential to
exacerbate negative and cognitive symptoms. Problematically, it’s a
difficult area to study, as so few individuals with psychosis are
not on treatment, and it’s realistically not possible to ethically
undertake such work. With those caveats in mind, an impressive
expert group investigated the best current evidence. Their
conclusions are that there are few data to support the
neurotoxicity hypothesis, with multiple confounders to such work;
further, although dopamine sensitization is recognised, it is not
clearly linked with worsened outcomes. We suggest it’s an important
read for those of us who prescribe such medication.
Finally, the guys and gals at UCL have been tempting us
with some corking recent publications. You may recall
their recent paper on cat ownership and psychosis; well now the
same team have evaluated how students rated a cross-sectional,
anonymised, set of photos of medics from different specialities.
The principle was to look at preconceptions, and who looked
professional, trustworthy, and aspirational; the topic matters,
especially when we think of the issues around recruitment. Scrubs
were a clear and helpful identifier of emergency medics, but
problematically, no women were identified as surgeons, something
pinned to men in suits. However, to cheer us up – or at least half
of us – male psychiatrists were identified as the most
fashionable of all doctors. Not something that surprised the
Kaleidoscope Column in the BJPsych
June's Kaleidoscope monthly Quiz (True or False)
Q1: An expert group evaluating antipsychotic
medications has found them, as a class, to have a therapeutic
effect size that compares favourably with the most effective
interventions in other branches of medicine.
A1: True. Something to keep in mind when faced
with the - reasonable - concerns about side-effects.
Q2: EEG and behavioural work has shown that
listening to ‘happy’ music helps restrict attentional focus and
thus help with work.
A2: False. ‘Happy’ music broadens attentional
focus; ‘sad’ music does the opposite.
Q3: Work on difference mice species has shown
that the phylogenetically ancient gene for the neuropeptide
arginine vasopressin has the strongest genetic link to the
evolution of parenting behaviour in mammals.