Serial dexamethasone suppression test in psychiatric inpatients

Corticosterone oscillations during mania induction in the lateral hypothalamic kindled rat-Experimental observations and mathematical modeling

Changes in the hypothalamic-pituitary-adrenal (HPA) axis activity constitute a key component of bipolar mania, but the extent and nature of these alterations are not fully understood. We use here the lateral hypothalamic-kindled (LHK) rat model to deliberately induce an acute manic-like episode and measure serum corticosterone concentrations to assess changes in HPA axis activity. A mathematical model is developed to succinctly describe the entwined biochemical transformations that underlay the HPA axis and emulate by numerical simulations the considerable increase in serum corticosterone concentration induced by LHK. Synergistic combination of the LHK rat model and dynamical systems theory allows us to quantitatively characterize changes in HPA axis activity under controlled induction of acute manic-like states and provides a framework to study in silico how the dynamic integration of neurochemical transformations underlying the HPA axis is disrupted in these states.

Associations between suicide attempts and elevated bedtime salivary cortisol levels in bipolar disorder

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA) axis abnormalities have been reported in bipolar disorder and also in suicidal behavior, but few studies have examined the relationship between suicidal behaviors and the HPA axis function in bipolar disorder, attending to and minimizing confounding factors. We compare HPA axis activity in bipolar individuals with and without suicidal behavior and unaffected healthy controls through measurement of salivary cortisol.

METHOD

Salivary cortisol was collected for three consecutive days in 29 controls, 80 bipolar individuals without a history of suicide and 56 bipolar individuals with a past history of suicide. Clinical factors that affect salivary cortisol were also examined.

RESULTS

A past history of suicide was associated with a 7.4% higher bedtime salivary cortisol level in bipolar individuals. There was no statistical difference between non-suicidal bipolar individuals and controls in bedtime salivary cortisol and awakening salivary cortisol was not different between the three groups.

LIMITATIONS

The measure of salivary cortisol was a home based collection by the study subjects and the retrospective clinical data was primarily based on their historical account.

CONCLUSIONS

Bipolar individuals with a past history of suicidal behavior exhibit hyperactivity in the HPA axis. This biological marker remains significant regardless of demographic factors, mood state, severity and course of illness. This finding in bipolar disorder is consistent with the evidence for altered HPA axis functioning in suicide and mood disorders and is associated with a clinical subgroup of bipolar patients at elevated risk for suicide based on their history, and in need of further attention and study.

A randomised controlled study of risperidone and olanzapine for schizophrenic patients with neuroleptic-induced acute dystonia or parkinsonism

The objective of this study was to compare the effects of risperidone and olanzapine in schizophrenic patients with intolerant extrapyramidal side effects (EPS) on first generation antipsychotics. We conducted an 8-week, rater-blinded, flexible dose study. Seventy patients with schizophrenia, who met the DSM-IV research criteria of having neuroleptic-induced acute dystonia or parkinsonism, were randomly assigned to risperidone or olanzapine group. The primary outcome was a comparison of the incidence of concomitant anticholinergic drugs usage between the groups to manage their acute dystonia and parkinsonism. The average doses of risperidone and olanzapine from baseline to study end point were 1.8-3.5 mg/day and 7.7-11.7 mg/day, respectively. There were no significant differences in demographic data, severity of EPS or psychotic symptoms between the groups at baseline assessment. Patients taking risperidone had significantly higher incidence of using anticholinergic drugs to manage acute dystonia or parkinsonism overall during the study (OR = 5.17, 95%CI = 1.49-17.88, P = 0.013). There was no significant between-group difference in the changing of rating scales of EPS and psychotic symptoms. The results of our study favour olanzapine as a better choice in schizophrenic patients with intolerant EPS. Double-blinded, fixed dose and different ethnical study for EPS-intolerant schizophrenic patients is needed to confirm the results of our study.

A systematic review of hypothalamic-pituitary-adrenal axis function in schizophrenia: implications for mortality

There is convincing evidence that environmental stress plays a significant role in modifying both mental and physical health. The biological mechanisms linking stress to ill health are not fully understood, but significant evidence points to a central role of the stress axes; the hypothalamic- pituitary-adrenal (HPA) axis and the sympathetic nervous system. Together these two systems link the brain and the body and are crucial in maintaining homeostasis as well as improving an organism's survival chances in the face of environmental challenge. There is evidence of altered HPA axis function in people with a range of mental disorders, and this may in part explain the poor physical health of people with psychotic, mood and anxiety disorders. This paper systematically reviews HPA axis function in people with schizophrenia and relates this to the pattern of physical health seen in this disease. In summary, the evidence suggests people with schizophrenia can experience both hyper- and hypo-function of the HPA axis. It is likely that this contributes to the pattern of poor physical health and premature mortality suffered by people with schizophrenia, in particular the high rates of cardiovascular and metabolic disturbance.

The lower limits of dexamethasone window in Chinese depressives

BACKGROUND

Previous studies have shown wide variation in plasma dexamethasone (DEX) concentrations following a standard 1-mg dexamethasone suppression test (DST), and significantly lower DEX concentrations in DST nonsuppressors compared with suppressors, suggesting that DEX pharmacokinetics/bioavailability is an important variable associated with DST nonsuppression.

METHODS

To determine the effect of plasma DEX levels on the DST in Chinese depressives, we measured plasma DEX and post-DEX cortisol levels at 4:00 PM in a group of 50 depressed outpatients, 28 anxiety outpatients, and 33 normal subjects during the course of 1-mg oral overnight DST.

RESULTS

We found a significant difference in the plasma DEX levels between DST nonsuppressors and suppressors in the depression group and overall subject population, and a significant negative correlation between the plasma DEX and cortisol levels in the depression, anxiety, and total groups. Within a DEX "window", the DST performance was enhanced, whereas the relationships between plasma DEX and post-DEX cortisol levels remained equally strong.

CONCLUSIONS

Our findings support a relationship between plasma DEX and post-DEX cortisol levels, a relationship that might be superimposed on the hypothalamic-pituitary-adrenal axis. Comparing our "window" range with those of previous studies, we suggest that Chinese depressives may have lower limits of plasma DEX window, and that ethnicity may be an intervening variable in both DST response and pharmacokinetics of DEX.

Plasma dexamethasone concentration and cortisol response during manic episodes

BACKGROUND

Despite the widespread study of the dexamethasone suppression test (DST) in patients diagnosed with major depression, it has been less well studied during manic and mixed states of bipolar disorder.

METHODS

Cortisol response to the administration of 1 mg of dexamethasone was studied in 44 patients diagnosed bipolar disorder, manic (n = 37) or mixed (n = 7). Dexamethasone levels and cortisol responses were compared between these groups. Four patients initially meeting criteria for bipolar disorder, mixed, and 7 patients initially meeting criteria for bipolar disorder, manic, all of whom were characterized as DST nonsuppressors, were retested after remission.

RESULTS

Dexamethasone levels were lower and cortisol levels higher in those patients diagnosed bipolar disorder, mixed. An inverse correlation was found between log-transformed dexamethasone levels and log-transformed cortisol levels at 3 PM (r = -.619, p < or = .001) and 10 PM (r = -.501, p < or = .001). In those subjects retested after remission, dexamethasone levels were higher and cortisol levels lower than during the manic and mixed states.

CONCLUSIONS

Disturbances in the hypothalamic-pituitary-adrenal axis are observed frequently during mixed states of bipolar disorder, but are also not uncommon in purely manic episodes. These changes appear to be state dependent and revert with treatment.