Schizophrenia, suicide and the serotonin story

Suicide in Australia: Do We Really Have A Problem?

In 1995, 2367 Australians lost their lives through suicide, and up to 100 times this number may attempt each year: Suicide has now become a major public health problem in Australia, which has seen the suicide rates in young males quadruple over the last 35 years or so. An analysis of current research on suicide and suicidal behaviour exploring possible causes and crosscultural issues, is discussed. As well, an extended definition of suicide as an intentional death and its antecedents provides the foundation for a discourse on the views now held by our corntemporary society. The paper argues that suicide not only is one of the most extreme consequences of personal psychosocial distress but also is often also an indicator of previous life events and environmental factors that potentiates for personal vulnerabilities.

Behavioral genetics of the depression/cancer correlation: a look at the Ras oncogene family and the 'cerebral diabetes paradigm'

This study investigates the causes of the observed linkage between depression and later onset of cancer. The prevailing view is that cancer in depressed patients results from a weakened immune system. However, molecular biologists have recognized that dysregulation of the ras proto-oncogene results in impaired serotonin and dopamine synthesis manifesting as major depression. A qualitative review of the literature showed that (1) studies using the Minnesota Multiphasic Personality Inventory showed a greater correlation between depression and later cancer onset than those employing other measures and (2) the more related the cancer type was to the Ras oncogene family, the greater the correlation between depression and later cancer onset. These results support the hypothesis that the ras proto-oncogene plays a role in the etiology of depression and could be the common denominator in long-observed depression/cancer linkages. Previous depression/cancer linkage studies are confounded in that they failed to analyze cancer type and accurately diagnose depression.

Addressing the health and lifestyle issues of people with a mental illness: the Healthy Living Programme

OBJECTIVE

The physical health and well-being of mental health patients have been a concern to health professionals for many years. However, very few positive gains have been made to address this problem. This paper outlines the efforts of the Inner North Brisbane Mental Health Service, Royal Brisbane and Women's Hospital, to design and implement a structured educational programme, aimed at addressing and encouraging healthy lifestyle behaviours in its community mental health service recipients.

METHODS

Three programme modules were designed, addressing the topics of Nutrition and Healthy Eating, Physical Health, and Community Based Activities and Interests. Referral of patients to the programme was by their case manager or doctor. At the conclusion of each module, participants were asked to complete a satisfaction survey evaluating the programmes. The survey also gathered feedback regarding any suggestions and/or recommendations to improve content suitability and relevance.

RESULTS

Since commencing the Healthy Living Program, each module has been conducted at least twice, the topic of Healthy Eating receiving the most referrals and therefore conducted most frequently. To date, 35 satisfaction surveys have been evaluated. The overwhelming majority of respondents offered very positive feedback about the programme, most being able to identify some healthy lifestyle changes they planned to make in response to programme attendance.

CONCLUSIONS

This paper highlights the importance of incorporating healthy lifestyle programmes into mental health service delivery. The majority of patients who have attended the Healthy Living Program have indicated satisfaction with the content, but as yet information pertaining to long-term lifestyle change has not been collated. The next phase aims to examine whether the programme attendance has more long-term outcomes in improving health and well-being and promoting healthy behaviour change of mental health service recipients.

More tryptophan hydroxylase in the brainstem dorsal raphe nucleus in depressed suicides

Deficient serotonin neurotransmission in suicide is indicated by reduced brainstem serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA), fewer 5-HT(1A) autoreceptors and reduced cortical serotonin transporter binding in suicide victims. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the synthesis of 5-HT, and alterations in TPH could explain some of these findings. We sought to determine the amount of TPH immunoreactivity (TPH-IR) in the dorsal (DRN) and median (MRN) raphe nuclei in suicides and controls. Brainstems of suicide victims and controls (n = 11 pairs) were collected at autopsy, matched for age, sex and postmortem interval, frozen and sectioned (20 microm). Immunoautoradiography, using an antibody to label TPH, was performed, slides exposed to film and autoradiograms quantified by a computer-based image analysis system. We examined sections every 1000 microm throughout the whole length of the nucleus, performing statistical analysis only on those subjects for whom the raphe was complete (n = 8 pairs). TPH-IR (microCi/g) was higher in suicides than controls (S: 300.8 +/- 70.8 vs. C: 259.6 +/- 40.7, t = 2.57, df = 7, P = 0.04) in the dorsal raphe nucleus (DRN), and not different between suicides and controls (S: 251.3 +/- 44.2 vs. C: 235.9 +/- 27.4, t = 1.49, df = 7, P = 0.18) in the MRN. DRN TPH-IR was higher in male suicide victims (MS) compared to male controls (MC; MS: 318.4 +/- 54.4 vs. MC: 271.9 +/- 22.5, t = 2.66, df = 6, P = 0.03). The analysis of TPH-IR area and density at each DRN rostrocaudal levels showed higher area and density in suicides compared to controls in the rostral DRN and lower area and density in the caudal DRN. TPH-IR, an index of the amount of TPH enzyme, in the DRN is higher in depressed suicides. More TPH may be an upregulatory homeostatic response to impaired serotonin release or less autoreceptor activation. Alternatively, the serotonin impairment in suicide may be due to hypofunctional serotonin-synthesizing enzyme.

Depression and chronic diabetic foot disability. A case report of suicide

Evidence at the scene of death and the postmortem examination led the pathologist to conclude suicide by intentional insulin overdose. The examination was conducted one day after the patient's death. The amount of insulin injected is not known, but levels of insulin in the vitreous gel were extremely high. While glucose and insulin are more stable in vitreous than in postmortem blood, the longer the delay between death and sample collection, the greater the uncertainty of the exact concentrations of substances at the time of death [42]. Patients with diabetes may have at their disposal the resources to end their lives; misuse of insulin and suicide by insulin overdose are presumably underreported events. Not only do diabetics have insulin available, but they may also have narcotics, tricyclic antidepressants or other drugs that are toxic at high doses. Even in the absence of depression, all patients with diabetes face multiple emotional issues related to the diagnosis and course of the disease. Diabetes often requires significant lifestyle changes, such as diet and physical activity, upon its diagnosis. Patients face the possibility of long-term, possibly debilitating, complications: vision loss, sexual dysfunction, and amputation. Any podiatrist who treats a large number of diabetic patients will encounter the situation of a patient at risk of losing a limb. A patient may consciously or unconsciously view amputation as punishment; limb loss interferes physically with bodily function and has extensive emotional consequences as well. It is important for patients to be involved with a healthcare team (including primary care physician, nurse educator, ophthalmologist, and podiatrist) that provides support throughout their lives [3]. As learned early on in podiatry school, podiatric physicians don't treat feet; they treat patients who have foot problems. It is as important to know when to refer a patient to the primary care physician or a psychiatrist for mental health complaints as it is to know when to refer a patient to an orthopedic surgeon for hip pain or to an ophthalmologist for vision problems. We do not propose that this patient's diabetic foot disease was the direct cause of his depression and suicide; however, the prevalence of depression in the general population and its even higher rates in patients with chronic medical illness require awareness of these problems by all members of the medical profession.

Beneficial effects of fenoldopam treatment on renal function in streptozotocin-induced diabetic rats

We have studied the effect of chronic treatment with dopamine D1 receptor agonist fenoldopam (1 mg/kg, i.p. daily for 6 weeks) on renal function and metabolic parameters in streptozotocin (STZ)-diabetic rats. Diabetes was induced by a single tail vein injection of STZ (45 mg/kg). STZ produced severe hyperglycemia, hypoinsulinemia, hypercholesterolemia, hypertriglyceridemia, hypertension and bradycardia. Fenoldopam treatment significantly reduced fasting but not fed blood glucose levels and lowered the blood pressure in diabetic animals. Significant change was not observed in insulin, cholesterol, triglyceride levels. Diabetic animals showed increase in AUCglucose and decrease in AUCinsulin during oral glucose tolerance test. Fenoldopam treatment did not significantly change these values in diabetic animals. STZ produced increase in serum urea, creatinine and blood urea nitrogen. Diuresis and urinary sodium retention was observed in diabetic animals. Renal hypertrophy was observed as seen from increased kidney weight/body weight ratio and increased total RNA content as well as decreased total DNA content. Fenoldopam treatment significantly lowered serum urea, creatinine and blood urea nitrogen. Urinary sodium retention was significantly reduced and renal hypertrophy was prevented with fenoldopam treatment as seen from the improved kidney weight/body weight ratio. Fenoldopam treatment significantly prevented reduction in total DNA content and increase in total RNA content further substantiating reduced renal hypertrophy. Our data suggest that STZ induced diabetes is associated with renal dysfunctions and fenoldopam treatment could be beneficial in a condition where diabetes mellitus co-exists with hypertension and compromised renal function.

Morphometry of the dorsal raphe nucleus serotonergic neurons in suicide victims

BACKGROUND

The serotonin deficiency hypothesis of suicide has been important heuristically. Few studies have directly examined the brainstem dorsal raphe nucleus (DRN) serotonin neurons. We determined the number and morphometry of DRN serotonergic neurons in suicide victims (n = 7) compared to controls (n = 6).

METHODS

Brainstems were collected at autopsy, fixed and cryoprotected. Tissue was sectioned, stained for Nissl and processed with an antiserum that cross-reacts with tryptophan hydroxylase. All DRN neurons were identified, counted and analyzed every 1000 microns. Neuron morphometry was characterized by soma area (micron 2), sphericity, perimeter, length and density (neurons per mm3).

RESULTS

Neuron number and density was higher in suicide victims (1,780 +/- 127 neurons/mm3) than controls (1,349 +/- 68). The DRN volume did not differ between groups (66 +/- 9 mm3 for controls vs. 67 +/- 5 mm3 for suicides). Mean neuronal area and sphericity did not differ between suicides and controls. The total number and the density of DRN neurons did not correlate with age.

CONCLUSIONS

The finding of an increased number of neurons indicates that impaired serotonergic transmission found in association with serious suicide attempts is not due to fewer neurons.

A comparison of grain, oil and beet pulp as energy sources for the exercised horse

High-grain diets for the exercising horse were compared with diets which provided 15% of the total caloric intake from either vegetable oil or a highly fermentable fibre source (beet pulp). Six Thoroughbreds age 3 years were fed one of 3 diets or 5 weeks in a replicated 3 x 3 Latin square. The CONTROL diet was 3.65 kg of sweet feed (SF), 0.9 kg of a protein/vitamin/mineral pellet and 5.45 kg of hay cubes. The FAT diet replaced 1.15 kg of SF with 0.45 kg of soybean oil and the FIBRE diet replaced 1.15 kg of SF with 1.36 kg of beet pulp. Horses were exercised 3 times per week on a high-speed treadmill. During the last week of each period, the horses performed a standardised exercise test (SET). A series of blood samples was drawn immediately before feeding and every 0.5 h for 3 h after feeding, throughout the exercise bout and 30 min post exercise. Plasma was analysed for lactate, glucose, cortisol, insulin, packed cell volume, total protein and triglycerides. Water intake was measured at regular intervals during SET day. Blood glucose was lower (P < 0.05) in the FAT-fed horses during the 3 h post feeding as compared to either CONTROL or FIBRE-fed horses. Insulin was lower (P < 0.05) in the FAT-fed both post feeding and throughout exercise. Cortisol was lower (P < 0.05) in the FAT than the CONTROL-fed during exercise. Following exercise, the FAT-fed drank more water (P < 0.01) than either CONTROL or FIBRE-fed. Substituting 15% of DE as vegetable oil had a greater effect on metabolic response to exercise than a 15% substitution of beet pulp.

Immunological influences in attention-deficit disorder and schizophrenia; is there a link between these two conditions?

This paper aims to explore the influence of the immune system on the pathobiochemistry of movement disorders (Tourette syndrome, obsessive compulsive disorders and attention-deficit disorder, with and without hyperactivity) and schizophrenia. In children, a temporal relationship has been observed between contraction of a group A beta-hemolytic streptococcal infection and subsequent presentation with one of the movement disorders. Pathology investigations reveal that elevated antineuronal antibodies are associated with movement disorders. Similarly, elevations in interleukin-1 beta and interleukin-6 have been reported in schizophrenia. It is now known that the immune system can be activated by conditions other than a viral or bacterial infection, such as: neurological insult, neurotoxicity--endogenous and environmental, neurotransmitter and cholesterol dysregulation. These latter avenues of immune system activation will be explored with respect to schizophrenia.

The estrogen connection: the etiological relationship between diabetes, cancer, rheumatoid arthritis and psychiatric disorders

For some considerable time, there has been a growing awareness that defective essential fatty acid metabolism plays a causal role in the pathogenesis of both schizophrenia and non-insulin-dependent diabetes mellitus (NIDDM) but the influence of defective essential fatty acid metabolism in the pathogenesis of rheumatoid arthritis and cancer is less well appreciated. An EFA deficiency, or defective EFA metabolism, negatively influences prostaglandin synthesis and glucose regulation and transport. Moreover, defective EFA metabolism negatively influences estrogen availability which contributes to the observed gender bias some of these illnesses manifest. While fluctuations of estrogen are known to contribute to the pathogenesis of these conditions, so also do fluctuations of IGF-II and there is some suggestion that IGF-II and insulin may well be inversely regulated. In addition, insulin-dependent diabetes mellitus (IDDM), rheumatoid arthritis, and schizophrenia are thought to be autoimmune disorders, while cancer is associated with immune system failure. Consequently, this paper aims to examine the pathophysiological similarities and differences between mental illness, diabetes, rheumatoid arthritis and cancer in respect of which the causal relationship that obtains between essential fatty acids, estrogen, IGF-II, glucose regulation and autoimmunity will be addressed.