M. Sarchiapone

Genetics of Suicide

ABSTRACT: Suicidal behavior, like so much else in psychiatry, tends to cluster in families. Clinical studies show that a family history of suicide is associated with a raised risk of both attempts at suicide and completed suicide. Twin studies show that monozygotic twins have a greater concordance for suicidal behavior than dizygotic twins. Adoption studies also suggest that there may be genetic factors in suicide. Most recently, molecular genetic studies report that polymorphisms of the tryptophan hydroxylase gene are associated with suicidal behavior.

Dopamine transporter binding in depressed patients with anhedonia

Central dopaminergic dysfunction has been widely proposed as a common neurobiological correlate of the psychopathological expression of anhedonia. The dopamine transporter (DAT) is a predominantly presynaptic receptor that may play a critical role in the pathophysiology of dopaminergic transmission. The aim of our study was to evaluate DAT binding in a population of depressed patients with anhedonia. Single photon emission computed tomography (SPECT) with the radiotracer DATSCAN was used to evaluate DAT binding in 11 depressed patients with anhedonia and 9 healthy comparison subjects. Compared with healthy subjects, patients showed significantly lower DAT binding. No significant correlation was found between DAT binding ratios and scores on administered psychometric tests. These findings suggest an alteration in DAT density in depressed patients with anhedonia that may be a primary susceptibility factor or a secondary phenomenon to reduced dopamine concentration in the synaptic cleft.

Cholesterol and serotonin indices in depressed and suicidal patients.

BACKGROUNDnProlactin and cortisol responses to d-fenfluramine challenge of central serotonin are reduced in depressed and suicidal patients. Low serum cholesterol levels are also reported in suicidal behavior. Thus, we examined for a relationship between serum cholesterol and fenfluramine challenge responses in patients with depression and/or attempted suicide.nnnMETHODSnWe studied 12 patients and six controls. Blood was drawn for baseline serum cholesterol and the d-fenfluramine challenge test performed.nnnRESULTSnSerum cholesterol levels were significantly lower in suicidal patients than in either non-suicidal patients or controls. However, neither the prolactin nor cortisol responses to d-fenfluramine correlated significantly with serum cholesterol levels.nnnCONCLUSIONnNo relationship was found between serum cholesterol and these peripheral indices of serotonergic function.

Further evidence for low serum cholesterol and suicidal behaviour

OBJECTIVEnTo examine for a relationship between serum cholesterol and suicidal behavior.nnnMETHODSnPatients admitted after an overdose (N=120) were compared with controls (N=120) for their serum cholesterol levels.nnnRESULTSnPatients who had overdosed had significantly lower serum cholesterol levels than controls (mean+/-S.D. 171+/-31 vs. 196+/-30 mg/dl, P<0.0001).nnnCONCLUSIONnThese results add to a grouping literature reporting that low serum cholesterol is associated with suicidal behavior.

A case of Cotard syndrome: 123I-IBZM SPECT imaging of striatal D2 receptor binding

A case of dèlire de nègation that suddenly appeared in a 43-year-old male is presented. No alteration in regional cerebral blood, as measured by (99m)Tc-HMPAO-SPECT, was found, but (123)I-IBZM-SPECT analysis showed reduced striatal D(2) receptor binding that further decreased after treatment.

Suicidal behaviour: genes, environmental stress and temperamental traits

Multiple risk factors have been involved in the risk for suiciden and multiple trajectories have been hypothesized leading to suicidal behaviour.n Consistent evidence suggests the involvement of heritable factors, as well as an critical role of life stress and early adversity. In the present article we willn review the evidence for the involvement of genetic, environmental as well asn personality traits in the risk for suicide, together with recent evidencen supporting an interaction between these different factors.