SYMPOSIA
SYMPOSIA
SYMPOSIA
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Abstracts of the Invited Speakers<br />
Psychotropic drugs effecting biological rhythm (Chronobiotics)<br />
Elif Oral<br />
Department of Psychiatry, Faculty of Medicine, Atatürk University, Erzurum, Turkey<br />
E-mail: oralelif@yahoo.com<br />
Biological clocks such as circadian, ultradian, and infradian rhythms have their own organizations, independently from environmental<br />
conditions. Although there is biological sustainability, psychiatric disorders and also psychotropic medications have important effects<br />
on the synchronization of biological clocks. Various biological mediators such as glutamate, γ aminobutyric acid, histamine, dopamine,<br />
acetylcholine, serotonin and their receptor systems take on the mediation of inner clocks via psychotropic drugs.<br />
Histaminergic activity is highly increased during wakefulness. H1 antagonists, generally increase Slow-Wave Sleep and stage 2 sleep<br />
and reduce rapid eye movement sleep. Diphenhydramine can cause subjective sedation and decreased sleep latency with no effect<br />
on memory or learning processes. The long elimination half-lives of these drugs can result in next-day sedation and impairment of<br />
psychomotor and cognitive function the next morning.<br />
Benzodiazepines shorten sleep-onset latency, increase total sleep time and stage 2 sleep, and suppress rapid eye movement sleep and<br />
slow-wave sleep. The risk of rebound insomnia is greatest with rapid elimination of benzodiazepines.<br />
About 65% of major depressive disorder patients report sleep complaints. Based on polysomnography studies, sleep architecture is<br />
estimated to be disturbed in up to 90% of depressed patients. Except desipramine, all TCAs block H1 and α1 receptors to varying degrees.<br />
As a general rule, the noradrenergic TCAs (e.g. desipramine, protriptyline) are considered ‘activating’. These agents have a tendency to<br />
increase sleep-onset latency as well as to decrease total sleep time, associated with an increase in wake time after sleep onset. Paroxetine<br />
and fluoxetine clearly suppress REM sleep, both among healthy volunteers and depressed patients. Compared to other SSRIs, citalopram<br />
may be less activating and therefore less likely to disrupt sleep continuity.<br />
Lithium and valproate have many acute, subacute, and chronic effects on systems, at the cellular and molecular levels. Lithium treatment<br />
modifies circadian rhythms in humans and in most animals, primarily by lengthening the period of the cycle.<br />
Most of the sleep-promoting effects of antipsychotic drugs have been related to their potency to antagonize α adrenergic, histaminergic,<br />
or cholinergic neurotransmission. Among classical antipsychotics, drugs having these properties, such as phenothiazines and<br />
thioxanthenes, are clearly sedative and promote sleep. Among atypical antipsychotics, drugs having this pharmacodynamics profile are<br />
olanzapine, clozapine, and quetiapine. Clozapine and olanzapine increase total sleep time and sleep efficiency and have no clear-cut<br />
effect on REM sleep.<br />
Key words: Psychotropic drugs, biological rhythm<br />
Bulletin of Clinical Psychopharmacology 2011;21(Suppl. 2):S88<br />
A general overview of chronotherapeutics<br />
Yavuz Selvi<br />
Department of Psychiatry, Yuzuncu Yil University, Van, Turkey<br />
E-mail: dryavuzselvi@yahoo.com<br />
The sleep-wake cycle occurs because of the two independent but additive processes, homeostatic sleep and circadian processes. Circadian<br />
rhythms play a significant role in regulating daily behavioral rhythms, cortisol and melatonin secretions, body temperature, sleep/wake<br />
cycle, alertness and performance levels. Disrupted synchronization of circadian rhythms impairs cognition, behavior and mood with<br />
deterioration of sleep-wake cycle and social rhythms. Some clinical and neurobiological findings suggest circadian dysregulation in<br />
depressive patients. Diurnal variation of mood, early morning awakening, phase advance for body temperature, cortisol, latency of the<br />
first phase of REM sleep for several other hormones and monoamines or their metabolites and sleep disturbances are core features of<br />
depression that have linked depression with circadian rhythm function (1,2).<br />
Clinical and neurobiological findings have promoted the idea that the restoration of circadian rhythm could have an antidepressant effect.<br />
The term, chronotherapeutics, refers to biologically-based, non-pharmaceutical and clinical interventions that act on disrupted biological<br />
rhythms in order to achieve therapeutic effects in the treatment of psychiatric conditions (3). Delayed therapeutic effects, tolerability,<br />
side effects, and drug–drug interactions of pharmacotherapeutic agents, as well as pregnancy and the postpartum period, prevent<br />
antidepressant use and promote chronotherapeutic interventions.<br />
S88 Bulletin of Clinical Psychopharmacology, Vol: 21, Supplement: 2, 2011 - www.psikofarmakoloji.org