Journal Digest

Noting the well-documented effects of sleep deprivation, researchers at the Stanford Sleep Disorders Clinic recently evaluated the rarely studied effects of sleep extension, using a cohort of 11 healthy members of the Stanford University men's varsity basketball team as their subjects.

The players maintained their usual sleep-wake schedule for a two- to four-week baseline period followed by a five- to seven-week sleep extension period. During sleep extension, the players obtained as much nocturnal sleep as possible, with a minimum goal of 10 hours each night.

Measures of athletic performance specific to basketball were recorded after every practice including a timed sprint and shooting accuracy. Reaction time, levels of daytime sleepiness, and mood were monitored via the Psychomotor Vigilance Task (PVT), Epworth Sleepiness Scale (ESS), and Profile of Mood States (POMS), respectively.

Total objective nightly sleep time increased during sleep extension compared with baseline by 110.9 +/- 79.7 minutes. Subjects demonstrated a faster timed sprint following sleep extension. Shooting accuracy improved. Mean PVT reaction time and ESS scores decreased. POMS scores improved with increased vigor and decreased fatigue subscales. Subjects also reported improved overall ratings of physical and mental well-being during practices and games. "Improvements in specific measures of basketball performance after sleep extension indicate that optimal sleep is likely beneficial in reaching peak athletic performance," said the researchers.

Researchers at the University of Texas at Austin recently discovered an unusual difference between the sexes: Older men who drink heavily or in a "binge" fashion were often depressed, isolated, and lonely compared with men who drank less or less often. Their female counterparts, however, were more social than older women who drank less.

They examined the role of gender similarity/difference in the association between depressive symptoms and frequency and amount of alcohol use among a representative sample of older adults, controlling for other depression risk/protective factors (sociodemographics, health status, social support and social engagement, and other health-related behaviors). Data came from the National Social Life, Health, and Aging Project Wave 1, which included a nationally representative probability sample (n=2,924) of community-dwelling individuals aged 57 to 85. Evaluation of participants included face-to-face interviews, which were the sources of information for this research.

Heavy/binge drinking was defined as the consumption of four or more drinks for men and three or more drinks for women per drinking day. Depressive symptoms were measured with the 11-item Center for Epidemiologic Scale for Depression. A significant proportion of both men (67.7 percent) and women (52.2 percent) had consumed alcohol in the preceding three months, and 12.3 percent of male and 8.4 percent of female drinkers were heavy/binge drinkers. Substantial differences between male and female heavy drinkers were found in sociodemographics, health status, and social support and social engagement. Older adult men who are heavy or binge drinkers were more likely than low/moderate drinkers to be divorced or separated; to have less education, income, and family/friend support; and to engage in physical activities less often. Older women who drank heavily, however, were more socially active than their female peers who abstaind or drank moderately.

The authors concluded that older men who engaged in heavy/binge drinking may use alcohol to cope with depressive mood, and heavy drinking might also contribute to their social isolation and depressive symptoms. Depression screening and treatment for older men should be accompanied by alcohol screening and treatment and vice versa, they said.

Add stress to high daily caffeine intake, and you may get hallucinatory symptoms, according to Australian researchers. They grouped 92 community-recruited individuals—free of psychiatric or neurological history, psychotropic medication use, and auditory impairment—by self-reported stress levels and caffeine intake.

Participants were asked to listen to white noise and to report each time they heard the song "White Christmas" during the white noise. Since the song was never played, each time a participant indicated hearing the song was recorded as a "false alarm." All of the participants thought they heard the song being played, but those in the high stress-high caffeine group had the most false alarms.

The researchers concluded that increased caffeine consumption, in the presence of high levels of stress, has the potential to increase the experience of psychotic symptoms, specifically auditory hallucinations. "Further caution needs to be exercised with the use of this overtly ‘safe’ drug," said the researchers, noting that the findings require further replication and support.

Researchers at the University of Utah, supported by grants from the National Institute on Drug Abuse, have elucidated the effects of the designer stimulant 4-methylmethcathinone (mephedrone) in a rat model. Mephedrone is one of a group of synthetic stimulants that have recently risen in popularity and raised serious health concerns (Psychiatric News, April 15). They are sold as a powdery substance in small-volume packets labeled as "bath salts" or "plant fertilizer." The products are ingested by swallowing or snorting, and they can cause chest pains, increased blood pressure, increased heart rate, agitation, hallucinations, extreme paranoia, and delusions. Owing largely to its recent emergence, there are no formal pharmacodynamic or pharmacokinetic studies of mephedrone.

Results of this study demonstrated that, similar to methylenedioxymethamphetamine, methamphetamine, and methcathinone, repeated mephedrone injections caused a rapid decrease in striatal dopamine (DA) and hippocampal serotonin (5-hydroxytryptamine; 5HT) transporter function. Mephedrone also inhibited both synaptosomal DA and 5HT uptake. Like methylenedioxymethamphetamine, but unlike methamphetamine or methcathinone, repeated mephedrone administrations also caused persistent serotonergic, but not dopaminergic, deficits. However, mephedrone caused DA release from a striatal suspension approaching that of methamphetamine and was self-administered by rodents. These data demonstrate that mephedrone has a unique pharmacological profile with both abuse liability and neurotoxic potential, said the researchers.

Despite a rise in the concurrent use of methylphenidate and fluoxetine for comorbid ADHD and major depression in children, little is known of the possibility of adverse effects from the combination.

Researchers recently examined the neurobiological consequences of concomitant exposure to the two medications by administering doses of saline, methylphenidate alone, fluoxetine alone, or the two drugs in combination to juvenile rats and assessing their reactivity to reward- and mood-related stimuli 24 hours or two months after the exposures. They also assessed mRNA and protein levels in the ventral tegmental area to assess effects of the administered drugs on a signaling cascade implicated in motivation and mood regulation.

Their results indicated that concurrent administration of methylphenidate and fluoxetine during preadolescence increased rats' sensitivity to reward-related stimuli while simultaneously enhancing susceptibility to stressful situations. They noted that the effects seen in the study were derived from "normal" animals, and similar treatment in an animal model of comorbid ADHD and depression might yield different results. "Our findings necessitate further study into the effects of early-life drug exposure on functional outcomes in adulthood," they said.