Bipolar Disorder and Diabetes Linked

July 19, 2017 · Posted in Risk Factors · Comment 

diabetes linked to bipolar disorderA systematic literature review in 2016 showed a definitive link between bipolar disorder and diabetes. Bipolar disorder almost doubles the risk of diabetes while diabetes more than triples the risk of bipolar disorder. The article by Ellen F. Charles and colleagues was published in the International Journal of Bipolar Disorders.

The review included seven large cohort studies. The studies, based on elderly populations only, examined bipolar disorder and diabetes rates. Charles and colleagues suggested that shared mechanisms could cause both illnesses. New disease models that explain the link between bipolar disorder and diabetes could lead to better treatments.

The review also reported that both bipolar disorder and diabetes were independently associated with risk of cognitive decline and dementia in these elderly individuals. People with diabetes had more brain atrophy on average than others who share their age and gender but did not have diabetes. People with bipolar disorder who also had diabetes and either insulin resistance or glucose intolerance had neurochemical changes in the prefrontal cortex that indicated poor neuronal health. In some cases, these patients also had reduced brain volume in the hippocampus and cortex.

In Case Control Study, Two-Thirds of Patients With Severe Depression Had Underlying Metabolic Abnormalities

July 18, 2017 · Posted in Diagnosis, Risk Factors · Comment 

depressed manA recent study suggests that potentially treatable metabolic abnormalities in the central nervous system may underlie a large proportion of cases of severe, treatment-resistant depression. These abnormalities, such as folate deficiency in the cerebrospinal fluid, are not screened for regularly, as they require a spinal tap to diagnose.

Researchers led by Lisa A. Pan were inspired to assess metabolic function in people with treatment-resistant depression after a young patient with severe, persistent depression who had attempted suicide several times improved dramatically after being diagnosed with a tetrahydrobiopterin deficiency in his cerebrospinal fluid and treated for the deficiency. Tetrahydrobiopterin is critical to the production of monoamine neurotransmitters.

The researchers carried out a case-control study of 33 teen and young adult patients who had had treatment-resistant depression since childhood and 16 healthy control participants. Twenty-one of the 33 patients with severe depression had metabolic abnormalities in their cerebrospinal fluid. Twelve had cerebral folate deficiencies (but no folate deficiency in blood tests). Those who took folinic acid for at least six weeks (1–2 mg/kg/day) in addition to their regular medications showed sometimes dramatic improvement in their depression.

Other metabolic issues identified in the patients with severe depression included abnormal levels of acylcarnitine in five patients, low tetrahydrobiopterin intermediates in one, low guanidinoacetate in another, and unusual creatine/creatinine ratios in three patients. None of the healthy participants had any metabolic abnormality.

While the study, published in the American Journal of Psychiatry in 2017, was small, it suggests that the underlying causes of some severe depression cases are going undiagnosed and untreated. The authors suggest that assessment of metabolic function should be more common in cases of severe treatment-resistant depression.

Depression Increases Heart Disease Risk to Same Extent That Obesity, High Cholesterol Do

July 17, 2017 · Posted in Risk Factors · Comment 

heart failureIn men, depression seems to be equal to obesity and high cholesterol in increasing heart disease risk. A German study about heart disease risk included 3,428 men between the ages of 45 and 74 who were observed over a period of 10 years.

In an article in the journal Atherosclerosis, lead researcher Karl-Heinz Ladwig reported that while high blood pressure and smoking are the most powerful risk factors for fatal cardiovascular disease, depression is comparable to obesity and high cholesterol levels. Depression accounts for about 15% of cardiovascular deaths.

Ladwig suggests that depression screening should be standard in patients with other risk factors for heart disease.

Editor’s Note: Long-term preventive treatment for depression may have the added benefit of preventing heart attacks. In people with two prior depressions, most guidelines now recommend lifetime continuation of antidepressant treatment.

Teens with Bipolar Disorder at Increased Risk for Cardiovascular Disease

July 14, 2017 · Posted in Comorbidities, Risk Factors · Comment 

teen blood pressure checkA scientific statement from the American Heart Association reported in 2015 that youth with major depressive disorder and bipolar disorder are at moderate (Tier II level) increased risk for cardiovascular disorders. The combined prevalence of these illnesses in adolescents in the US is approximately 10%.

There are many factors that contribute to this risk, including inflammation, oxidative stress (when the body falls behind neutralizing harmful substances produced during metabolism), dysfunction in the autonomic nerve system, and problems with the endothelium (the inner lining of blood vessels). Lifestyle factors include adversity in early life, sleep disturbance, sedentary lifestyle, poor nutrition, and abuse of tobacco, alcohol, or other substances.

Taking some atypical antipsychotics as treatment for bipolar disorder also contributes to the risk of cardiovascular problems by increasing weight and/or lipid levels. Among the atypicals, ziprasidone (Geodon) and lurasidone (Latuda) come with the lowest likelihood of weight gain.

The statement by Benjamin I. Goldstein and colleagues that appeared in the Heart Association-affiliated journal Circulation suggested that therapeutic interventions should address some of these risk factors to help prevent cardiovascular problems and improve life expectancy for young people with depression or bipolar disorder. These could include a good diet, regular exercise, and treatments with good long-term tolerability that are aimed at preventing episodes.

The Role of Inflammatory Markers and BDNF

Inflammation worsens the risk of cardiovascular problems, while brain-derived neurotrophic factor (BDNF), which protects neurons and plays a role in learning and memory, may improve prospects for someone with depression or bipolar disorder.
A 2017 article by Jessica K. Hatch and colleagues including Goldstein in the Journal of Clinical Psychiatry suggests that inflammation and BDNF are mediators of cardiovascular risk in youth with bipolar disorder. The study looked at 40 adolescents with bipolar disorder and 20 healthy controls.

Those with bipolar disorder had greater waist circumference, body mass index, and pulse pressure than the controls. The youth with bipolar disorder also had higher levels of the inflammatory cytokine Il-6. Participants who had lower BDNF had greater thickness of the carotid vessel internal lining (intima media).

Hatch and colleagues point to the importance of prevention strategies in adolescents with these indicators of increased cardiovascular risk. These data complement the American Heart Association’s recognition of adolescent mood disorders as a large problem that deserves wider attention both in psychiatry and in the media.

Topiramate Plus Antipsychotic Medication Better Than Antipsychotics Alone for Schizophrenia Spectrum Disorders

May 30, 2017 · Posted in Current Treatments · Comment 

womanA 2016 meta-analysis has shown that the combination of the anticonvulsant topiramate and antipsychotic medication reduces symptoms of schizophrenia spectrum disorders more than antipsychotic medication alone. Researchers led by Christoph U. Correll analyzed the results of eight studies in which the topiramate-antipsychotic combination was compared to antipsychotics alone or with placebo.

The combination of topiramate and antipsychotic medication was superior at reducing general psychopathology, including both negative and positive symptoms of schizophrenia. The combination was also associated with lower body weight and body mass index (BMI) compared to antipsychotics alone.

The studies included in the meta-analysis used a variety of antipsychotic medications. When these were compared, the combination of topiramate and clozapine was more effective than other combinations at reducing psychopathology. However, the combination of topiramate and clozapine was also associated with less weight loss than combinations using other antipsychotics.

In terms of side effects, topiramate was associated with more paresthesia (a burning or prickling sensation, often in the hands or feet) than placebo.

The study was published in the Journal of Clinical Psychiatry.

FDA Approves Treatment for Tardive Dyskinesia

May 26, 2017 · Posted in Current Treatments · Comment 

facesA new drug valbenazine (trade name Ingrezza) has been approved by the US Food and Drug Administration for the treatment of tardive dyskinesia. Tardive dyskinesia, a side effect of long-term use of antipsychotic medication, consists of involuntary movements of the tongue, face, torso, arms, and legs. It can interfere with walking, talking, and breathing.

The approval followed 20 clinical trials of valbenazine that included a total of more than 1000 participants who had symptoms of tardive dyskinesia in addition to schizophrenia, schizoaffective disorder, or bipolar disorder.

In a 2017 article in the American Journal of Psychiatry, researcher Robert A. Hauser and colleagues reported that patients who received 80 mg/day of valbenazine had a significant reduction in tardive dyskinesia symptoms after six weeks compared to those who received placebo. Participants who received 40 mg/day of valbenazine also had reductions in symptoms, although not as dramatic as with the higher dose.

Serious side effects of valbenazine include sleepiness and lengthening of the QT interval, which can increase heart arrhythmias. The FDA notes that people who already have abnormal heartbeats due to a long QT interval should not take valbenazine. In addition, people taking the drug should avoid driving or operating heavy machinery until they know how valbenazine affects them.

Levels of Amino Acid Proline Interact with COMT Genotype to Affect Negative Symptoms

May 24, 2017 · Posted in Course of Illness, Genetics, Neurobiology · Comment 

DNAIn a 2016 article, researcher Catherine L. Clelland and colleagues reported that a patient’s levels of the amino acid proline interact with their genetic profile to influence the seriousness of their negative symptoms. Negative symptoms of schizophrenia and bipolar disorder include flat affect and lack of volition and can be some of the hardest symptoms to treat.

High levels of proline in the central nervous system have been linked to schizophrenia. Proline is a precursor to the neurotransmitter glutamate, and high proline levels have been found to alter glutamate and dopamine signaling in mice. This is one of the factors affecting negative symptoms.

The other factor affecting negative symptoms is the COMT gene. The enzyme catechol-o-methlyl transferase (COMT) metabolizes dopamine in the prefrontal cortex. There are several common versions of the gene for COMT. The most efficient is known as val-158-val, identifying that the gene has two valine amino acids at position 158. People with high proline levels and the val-158-val version of the COMT gene had fewer negative symptoms than people with high proline levels and another version of the gene, val-158-met (indicating one valine and one methionine amino acid at position 158).

Clelland and colleagues hypothesized that high proline levels may actually counteract the dopamine shortages common in the prefrontal cortex in people with the val-158-val genotype of COMT, which is more efficient at breaking down dopamine in this region.

The mood stabilizer valproate increases proline levels. In the study, which was published in Translational Psychiatry, people with schizophrenia and the val-val genotype had fewer negative symptoms when treated with valproate than those with the val-met genotype who received the same treatment.

Lithium Responders and Non-Responders Have Different Neuron Characteristics

May 22, 2017 · Posted in Current Treatments · Comment 
after hyperpolarization

After hyperpolarization (via Wikimedia Commons)

A 2017 study in the journal Molecular Psychiatry suggests that by observing the neurons of a person with bipolar disorder, you can predict whether they will respond to lithium treatment. The drug is effective in approximately 30% of those to whom it is prescribed.

Researchers led by Shani Stern and Renata Santos used stem cell research to analyze neurons from people with bipolar disorder and healthy controls.

People with bipolar disorder shared some neuron features, namely a large, fast after-hyperpolarization (a phase in which the cell’s membrane changes), which is followed by a resting period before the neuron can fire again. The large, fast hyperpolarization in people with bipolar disorder speeds up this cycle, leading to fast and sustained neuron firing. This replicated previous findings by the same researchers, which found that people with bipolar disorder are more sensitive to stimuli. In people with bipolar disorder, the threshold for a neuron to fire drops with each subsequent after-hyperpolarization.

Chronic lithium treatment reduced this hyperexcitability in some patients—and these were the patients who had a good response to lithium treatment.

Among the study participants with bipolar disorder, there were differences in the neuron profiles of those who responded well to lithium versus those who did not.

Stern and colleagues programmed a computer to recognize the electrophysiological features of neurons from lithium responders and non-responders. The computer could then analyze the neurons of a patient whose response to lithium was unknown and predict with a greater than 92% success rate whether that patient had responded well to lithium treatment.

Weight Loss Drug Lorcaserin Cuts Opiate Use in Rats

May 19, 2017 · Posted in Potential Treatments · Comment 

lab ratLorcaserin is a drug approved for weight loss in very obese patients. It stimulates serotonin 5 HT-2c receptors thought to control appetite by inducing the secretion of the polypeptide pro-opiomelanocortin. In a 2017 article in the journal ACS Chemical Neuroscience, researcher Kathryn Cunningham and colleagues reported that the drug had reduced opiate use and craving in rats. Previous research by Cunningham showed that lorcaserin reduced cocaine seeking in rats.

Most treatments for opiate addiction work by occupying opiate receptors so that opiates are prevented from stimulating them, thus reducing the pleasurable effects of the opiates. It is not yet well understood how drugs like lorcaserin that target serotonin 5 HT-2c receptors affect the brain’s reward system.

In the study, rats were trained to self-administer oxycodone. They were also trained to associate certain lights and sounds with oxycodone availability. Lorcaserin reduced the rats’ drug-seeking behavior and also weakened the link between the light and sound cues and the drug-seeking behavior.

Future research may explore whether drugs like lorcaserin can reduce opiate use in people.

Currently, there are a few options to treat opiate addiction. N-acetylcysteine (NAC) is an over-the- counter (nonprescription) drug that has been shown to decrease opiate use in both animals and humans. NAC also decreases use or craving for many other drugs of abuse including cocaine, alcohol, nicotine, and marijuana. NAC reduces the excitatory glutamate signal in the reward area of the brain (the nucleus accumbens) by increasing the number of transporters carrying glutamate out of the synapse and into glial cells. It has an excellent side effects profile and can readily be used in opiate-addicted patients.

Opiate replacement therapy with methadone or the partial opiate agonist buprenorphine is one treatment option for opiate addiction. Buprenorphine is also combined with the opiate antagonist naloxone in a drug called Suboxone, which can reduce opiate use. Naloxone is a pure opiate antagonist that can rapidly reverse the respiratory-suppressing effects of an overdose of opiates.

Disrupting Memories of Cocaine Use Might Prevent Relapse

May 17, 2017 · Posted in Potential Treatments · Comment 

cocaine treatment

Cocaine users who want to abstain from the drug may find that encountering people or places who remind them of past cocaine use can increase their cravings for the drug and lead to relapse. Researchers are studying animals to see if disrupting the link between an environmental cue and the memory of cocaine’s effects could reduce cravings for the drug.

In a 2016 article in the journal Neuropsychopharmacology, researcher Melissa S. Monsey and colleagues reported that in rats, the amnesia-causing natural compound garcinol can weaken the cues that lead to a cocaine-seeking. Garcinol is derived from the rind of kokum (or Garcinia indica) fruit, which is native to the west coast of India.

Monsey and colleagues delivered the garcinol during a period when the rats’ brains were reconsolidating memories that linked an environmental cue with the pleasurable effects of cocaine.

For 12 days, the rats in the study could press a lever and receive an intravenous infusion of cocaine that was paired with a light and a sound. Then the lever stopped working for 8 days. Next, the researchers observed how the rats behaved when the light and sound returned.

The light and sound were meant to remind the rats of the previous times they received cocaine, prompting their brains to reconsolidate the memory linking the light/sound with the pleasurable effects of cocaine.

Half of the rats were given an injection of garcinol during this memory reconsolidation period. While all of the rats continued to seek out cocaine, in the garcinol-treated rats, the light/sound was no longer linked to cocaine. Their cocaine-seeking behavior from then on was unrelated to the light/sound, and the link between the light/sound and cocaine could not be reinstated in these rats.

This research on rats may help clarify how cravings are produced in the brain, and how they might be prevented or treated.

Editor’s Note: In 2012, Yan-Xue Xue and colleagues reported in the journal Science that in humans, psychological techniques can be used to help a patient unlearn the association between an environmental cue and the effects of a drug, using the same theory of the memory reconsolidation period. When patients in recovery from heroin addiction were prompted to revisit memories of heroin use 10 minutes before extinction training (in which they looked at heroin or heroin paraphernalia without receiving the drug), they ended up with fewer cravings for heroin 1, 30, and 180 days later compared to patients who did extinction training without revisiting memories of past heroin use (and thus without opening the memory reconsolidation window, which researchers believe opens 5 minutes to an hour after someone engages in active recall).

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