Tag Archives: bipolar

Calcium dynamics & psychiatric illness.

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calcium transientsThe alpha subunit of the L-type calcium channel (CaV1.2) is encoded by the gene CACNA1C. An apparently obscure protein, CaV1.2 has risen to prominence in the last five years.

Several large scale genome-wide association (GWAS) studies are in agreement that variation in CACNA1C is associated with bipolar disorder and schizophrenia. Additionally, mutations in CACNA1C are a direct cause of autism. As a consequence, Ca2+ signalling has begun to receive attention amongst psychiatrists.

A recent review by Michael Berridge is the ideal introduction to Ca2+ dynamics. Calcium does not only enter cells via channels. There are intracellular stores, which can be stimulated to release Ca2+ into the cytosol. Neurotransmitters such as serotonin, noradrenaline and glutamate can invoke the release of Ca2+  from intracellular stores by way of an intermediate 2nd messenger pathway, the phosphatidylinositol 4,5 biphosphate (PIP2) system. Berridge is best known for having deciphered the foundations of the PIP2 system in the 1980’s and as such he is an authoratative guide for the relevance of calcium signalling to psychiatric disorders.

The full paper is available here.

Psychosis Research. Where have we been & where are we going?

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phenotype and genotype

The Institute of Psychiatry at The Maudsley is the largest centre for psychiatric research in Europe. Recently a group of leading researchers were tasked with summarising an area of research as it pertains to psychosis and psychopharmacology.

The outcome was a series of short lectures, delivered to a lively audience of psychiatrists, mental health workers and psychologists at The Maudsley. The lecture slides and audio are now available below and constitute a unique training resource for those who treat patients.

1. Sir Robin Murray,
“Psychosis research: Deconstructing the dogma“
2. David Taylor,
“Current Psychopharmacology: Facts & Fiction“
3. Oliver Howes,
“How can we Treat psychosis better?“
4. Marta DiForti,
“An idiot's guide to psychiatric genetics“
5. Sameer Jauhar,
“Ten psychosis papers to read before you die!”
6. Paul Morrison,
“Future antipsychotics“

 

Guidelines for the Management of Bipolar Disorder.

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turner

The first German-language guidelines for the management of bipolar disorder were published in 2012, and now, an abbreviated English translation is available online for free [link].

The German Society for Bipolar Disorder (DGBS) and the German Association for Psychiatry & Psychotherapy (DGPPN) set up a project group, a steering group and 6 working groups made up of psychiatrists, psychotherapists, patients and their families. Devoid of any industry funding, their intention was to provide “decision-making support for patients, their families, and therapists“. Following an extensive literature review, and ten consensus conferences they concluded:

“Bipolar disorder should be diagnosed as early as possible. The most extensive evidence is available for pharmacological monotherapy; there is little evidence for combination therapy, which is nonetheless commonly given. The appropriate treatment may include long-term maintenance treatment, if indicated. The treatment of mania should begin with one of the recommended mood stabilizers or antipsychotic drugs; the number needed to treat (NNT) is 3 to 13 for three weeks of treatment with lithium or atypical antipsychotic drugs. The treatment of bipolar depression should begin with quetiapine (NNT = 5 to 7 for eight weeks of treatment), unless the patient is already under mood-stabilizing treatment that can be optimized. Further options in the treatment of bipolar depression are the recommended mood stabilizers, atypical antipsychotic drugs, and antidepressants. For maintenance treatment, lithium should be used preferentially (NNT = 14 for 12 months of treatment and 3 for 24 months of treatment), although other mood stabilizers or atypical antipsychotic drugs can be given as well. Psychotherapy (in addition to any pharmacological treatment) is recommended with the main goals of long-term stabilization, prevention of new episodes, and management of suicidality. In view of the current mental health care situation in Germany and the findings of studies from other countries, it is clear that there is a need for prompt access to need-based, complex and multimodal care structures. Patients and their families need to be adequately informed and should participate in psychiatric decision-making“.

The abridged guidelines (in English) are available here.

 

BD or not BD?

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The Bipolar Spectrum: can brain scans resolve diagnostic uncertainty?

The concept of manic-depression was extended some years back to cover less extreme manifestations characterised by hypomania (Bipolar II), as well as the classical form, defined by mania (Bipolar I). But other forms (perhaps less dramatic, though still a cause of much suffering) also exist.

These ‘softer’ forms of bipolar illness appear to blur into unipolar depression and perhaps also with the category which has been termed, borderline personality disorder. Although there has been a trend to view psychiatric disorders as points on a spectrum, rather than as discrete, encapsulated diagnoses, many psychiatrists would hesitate to equate borderline personality disorder and bipolar illness. Ultimately the matter will be resolved when we fully grasp the underlying neurobiology of affective disorders.

A new paper from researchers based in Sydney provides an authoritative and balanced account of the current state of our knowledge. The authors elegantly summarise the functional MRI literature across the hypothesised spectrum. One feature appears to be common across the various disorders – limbic hyperactivity. Perhaps this is not so surprising as the limbic system is the ‘seat’ of emotion, and all the various disorders/forms are characterised by emotional upset.

But there also appear to be differences. For example, the orbitofrontal cortex (a higher centre, which ‘dampens’ and regulates emotion) appears to be underactive in bipolar I, but not in unipolar depression nor in borderline personality disorder.

Further work will be needed before clear-cut conclusions can be drawn. The authors conclude…”Eventually, as the respective signatures of personality-based emotional dysregulation and bipolar mood dysregulation become increasingly crisp, we may be able to use functional neural profile to assist in clarifying diagnosis or treatment options in clinically muddy presentations, although a great deal of work will need to be done before imaging will be sufficiently robust to be used in this manner.”

The full paper can be read here:

http://www.expert-reviews.com/doi/pdfplus/10.1586/ern.12.126

 

N-acetylcysteine: Effective in bipolar depression?

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N-acetylcysteine (NAC) is a derivative of the naturally occurring amino-acid cysteine. Many people use it as a nutritional supplement, but NAC also has clear pharmacological properties. By far the most important role of NAC is as an ‘antidote’ in cases of paracetamol overdose. In this role, it can be life-saving.

However, the properties of NAC may extend beyond the emergency room. Recent research from Australia suggests it might be effective in the depressive phase of bipolar disorder. http://www.scielo.br/pdf/rbp/v33n4/v33n4a11.pdf

Larger studies are needed, but if the initial promise holds true, this would represent an important advance. In bipolar disorder, the depressive phase can be extremely difficult to shift, although conventional pharmacology has also made some significant inroads in the past few years. http://journals.psychiatryonline.org/data/Journals/AJP/4013/1351.pdf