Recent Papers on Depression
1. Inflammatory behaviour
There is increasing evidence that chronic inflammation may alter mood and impact on the development of depression.
Patients with depression have higher levels of inflammatory cytokines and acute-phase proteins. Admin of stimulators of inflammation has been associated with symptoms of depression.
It has been shown that cytokines are involved in many pathways known to be central to depression mechanisms such as production of monamines, neuroendocrine function and various other mechanisms of mood regulation.
Various drug targets have been identified that may be useful in the treatment of the depressed and inflamed patient. These targets include various factors involved in the cyclooxygenase and MAP kinase pathways, and NF-κB, various cytokines and chemokines.
Factors contributing to a pro-inflammatory state such as stress, poor diet, obesity, a leaky gut, a T-cell imbalance in favour of inflammation could be relevant to depression and relapse and could be targets for treatment.
Identifying mechanisms by which pro- and anti-inflammatory cytokines might influence mood could in the future lead to personalized treatments to the depressed patient with an inflammatory component to their illness.
Haroon et al. Neuropsychopharmacol 2011 Sep 14. doi: 10.1038/npp.2011.205. [Epub ahead of print].
PMID: 21918508 [PubMed – as supplied by publisher]
2. Drugs for Geriatric Mood Disorders
Few new drugs have been developed to treat the major mood disorders, bipolar and depression.
In the treatment of the elderly depressed patient, the aim is to develop newer strategies with higher remission. They include combining antidepressants, mood stabilizers and psychotherapy to treat specific symptom clusters. One example is the additional treatment of cognitive impairment symptoms with cholinesterase inhibitors.
The use of genetic information to predict drug treatment outcomes has recently been investigated.
In the future, more individualized treatment combinations may improve outcomes and result in less adverse effects.
Diniz BS, Nunes PV, Machado Viera R, et al. Curr Opin Psychiatry 2011 Sep 13. [Epub ahead of print]
PMID: 21918446 [PubMed – as supplied by publisher]
3. Positive Mum Helps the Depressed Teenager
How parents express their emotions during interactions with their teenagers impact greatly on their children’s mood and their life adjustments. In this study, it was investigated to see if symptoms of depression in teenagers were associated with neural activity during exposure to their mothers’ behaviour.
A functional MRI of the brains of 30 adolescents (18 females, mean age 17) participated in a task that used video clips of their own mother’s and an unrelated mother affective behavior as stimuli. Adolescents with symptoms of depression showed reduced rostral cingulated activity during exposure to their own mother’s behaviour and reduced striatal activity during exposure to positive behavior in general.
In the light of this study and other evidence, it may be that there may be a deficit in the reward function during depression.
Adolescents’ depressive symptoms moderate neural responses to their mothers’ positive behavior.
Whittle S, Yücel M, Forbes EE, et al. Soc Cogn Affect Neurosci. 2011Sep 14. [Epub ahead of print]
PMID: 21917846 [PubMed – as supplied by publisher]
4. Endocannabinoids and mood
There is increasing evidence of the role of the endocannabinoid (EC) system in the regulation of mood due to its role in the balance of cortical excitation and inhibition.
Anandamide, tetrahydrocannabinol (THC) and cannabidiol (CBD) have antidepressant, antipsychotic, anxiolytic, analgesic, anticonvulsant actions. This suggests there may be a treatment opportunity in mood and related disorders and this is proposed in this paper.
Post mortem and other studies have shown EC abnormalities in people suffering from depression, schizophrenia and in those who have committed suicide. Abnormalities in the cannabinoid-1 receptor (CNR1) gene that codes for cannabinoid-1(CB1) receptors are reported in psychiatric disorders.
There is limited evidence showing the efficacy of exogenous cannabinoid treatments in psychiatric disorders but it seems suggestive of a possible benefit. Further research is needed to see if there is benefit.
Acta Psychiatr Scand. 2011 Oct; 124 (4): 250-61. doi: 10.1111/j.1600-0447.2011.01687.x. Epub 2011 Mar 9.
PMID: 21916860 [PubMed – in process]
5. Drugs for depressed children and teenagers
Antidepressants are used in younger patients for the treatment of psychiatric disorders particularly in more severe cases. Non-pharmacological methods such as psychotherapy are more likely to be used for mild to moderate symptomatology. This paper reviews the drug choices.
In general, it is suggested that the first-choice medication for the treatment of juvenile unipolar depression is the selective serotonin reuptake inhibitor (SSRI) fluoxetine, which is recommended due to its efficacy and approval. Second-choice SSRIs include sertraline, escitalopram and citalopram are recommended.
Tricylics, alpha-2-adrenoceptor antagonists and SNRIs are alternative second choice options.
Taurines R, Gerlach M, Warnke M. World J Biol Psychiatry 2011 Sep;12 Suppl 1:11-5.
PMID: 21905988 [PubMed – in process]
6. Suffering in Silence
Many people don’t go to their doctor about their depression.
In this study in California, a telephone survey was conducted of over a thousand adults that were part of a previous behavioural survey.
The people were asked about their reasons for not disclosing symptoms, their beliefs related to depression-related beliefs and demographic characteristics.
The most frequent reason given was that they did not want to be prescribed antidepressants.
Those who did not have a history of depression said that depression falls outside the remit of primary care and that they were worried about being referred to psychiatrists.
Those who were clinically depressed had more personal barriers to seeking help than those without symptoms of depression.
Various socioeconomic factors had an influence including being female, poorer, negative or stigmatising beliefs about depression, symptom severity, and absence of a family history of depression.
The conclusions from this study is that many people are negatively predisposed to disclose their depression to doctors. Interventions should be encourages to get people to tell the doctor about their depression and doctors should ask specifically about it.
Bell RA, Franks P, Duberstein PR, et al. Ann Fam Med 2011 September-October; 9(5): 439-446.
PMID: 21911763 [PubMed – as supplied by publisher].
7. Effect of prayer on depression
In a European wide study, the impact of religiosity on depression was examined in people over 50. Using evidence from some simple models it has been suggested that may be religiosity, as measured by the frequency of prayer, is associated with a higher level of depression. These models however did not separate cause and effect, ie is the increased praying due to the presence of depression as opposed to vice versa. In this study, a model was developed using a different design to circumvent this. The authors found that prayer has a positive effect in that it leads to a lower level of depressive symptoms.
Denny KJ. Soc Sci Med 2011 Aug 26. [Epub ahead of print]
PMID: 21911275 [PubMed – as supplied by publisher]
8. Sleep, Mood and Anxiety
There is a known link between sleep disturbance and anxiety and depression. But little is known of the cause of this link.
In this study, the genetic and environmental influence on this association was estimated.
Using 1556 young adults (both twins and sibling pairs) questionnaire found sleep disturbance was moderately correlated with symptoms of anxiety and depression.
It was found that there was a major influence in the genes that affect the symptoms of sleep disturbance and of anxiety and depression. In particular in the case of the anxiety link it was found the genes played a greater role.
The authors concluded that although sleep disturbance is related to the presence of various psychiatric difficulties, it should be treated and considered independently.
Associations between sleep quality and anxiety and depression symptoms in a sample of young adult twins and siblings
Gregory AM, Buysse DJ, Willis TA et al. J Psychosom Res 2011 Oct; 71(4): 250-5. Epub 2011 May 20.
PMID: 21911103 [PubMed – in process]
9. Is Trial Evidence Really Best for Bipolar?
The randomized clinical trial (RCT) is the established to study human treatments, but there are a number of biases and limitations to this approach.
In this study, all of double-blind RCTs for treating bipolar were reviewed in journals with a high impact factor. Thirty articles were reviewed.
Small numbers less than 50 and pharmaceutical sponsorship of papers were two biases highlighted. The authors said these treatment studies and the limitations hinder their clinical usefulness and compromise the consistency of the findings.
Strech D, Soltmann B, Weikert B, et al. J Clin Psychiatry. 2011 Jun 25. [Epub ahead of print]
PMID: 21294992 [PubMed – as supplied by publisher]
10. Zinc deficiency and depression
Postgraduate students were investigated to see if there dietary zinc levels were associated with depression. Four hundred and two students were studied. An inverse relationship was found between zinc levels and depression which held when it was controlled for potential confounders. The authors suggest that long term zinc deficiency may modulate depressive symptoms.
Yari T, Aazami S. Biol Trace Elem Res. 2011 Sep 20. [Epub ahead of print]. Dietary Intake of Zinc was Inversely Associated with Depression.
PMID: 21932045 [PubMed – as supplied by publisher]