Insomnia is a significant problem among euthymic patients with bipolar disorder. Components of cognitive behavior therapy for insomnia, especially stimulus control and cognitive therapy, may be a helpful adjunct to treatment for patients with bipolar disorder.

No abstract

A drink containing branch chain amino acids is well tolerated in healthy volunteers and produces effects consistent with lowered dopamine function.

A nutritional intervention that decreases tyrosine availability to the brain acutely ameliorates manic symptoms. Further studies are required to assess whether this approach has longer-term efficacy.

A 62 g BCAA/TRP mixture decreases the availability of TYR and PHE for brain catecholamine synthesis and increases plasma prolactin consistent with lowered brain dopamine function. Addition of 2 g TRP to the 60 g BCAA mixture does not prevent a reduction of the ratio TRP:BCAA relative to placebo. The effects of the BCAA/TRP mixture on decision-making suggest a general action of dopamine pathways on the processing of emotional information in risky choice, including punishment-related cues, consistent with suggestions that dopamine mechanisms mediate behavioural responses to aversive as well as appetitive stimuli in instrumental conditioning.

Slowing of the rate at which a rivalrous percept switches from one configuration to another has been suggested as a potential trait marker for bipolar disorder. We measured perceptual alternations for a bistable, rotating, structure-from-motion cylinder in bipolar and control participants. In a control task, binocular depth rendered the direction of cylinder rotation unambiguous to monitor participants' performance and attention during the experimental task. A particular direction of rotation was perceptually stable, on average, for 33.5 s in participants without psychiatric diagnosis. Euthymic, bipolar participants showed a slightly slower rate of switching between the two percepts (percept duration 42.3 s). Under a parametric analysis of the best-fitting model for individual participants, this difference was statistically significant. However, the variability within groups was high, so this difference in average switch rates was not big enough to serve as a trait marker for bipolar disorder. We also found that low-level visual capacities, such as stereo threshold, influence perceptual switch rates. We suggest that there is no single brain location responsible for perceptual switching in all different ambiguous figures and that perceptual switching is generated by the actions of local cortical circuitry.

We report the case of a bilingual Italian-English aphasic patient, ED, who was very poor at categorising Italian nouns for grammatical gender in explicit, metalinguistic tasks, and was at chance when gender could not be inferred from the word's phonology. In contrast, ED showed a good ability to modify adjectives to match the gender of nouns in a task that involved translating adjective-noun phrases from English into Italian. Access to wordspeci c gender knowledge in aphasic patients should not be tested solely by means of tasks requiring explicit gender judgements but should be assessed using tasks that come as close as possible to the circumstances of natural language processing.

We recently found that administration to humans of a mixture of the three branch chain amino acids (BCAA) (valine, leucine and isoleucine) lowered the plasma ratio of tyrosine (TYR) and its precursor phenylalanine (PHE) to BCAA and increased plasma prolactin (PRL) (Gijsman et al. 2001). The latter finding supports the notion that the BCAA mixture, through restricting TYR entry to the brain, decreases aspects of brain dopamine (DA) function. However, the BCAA mixture also lowered the ratio of plasma tryptophan (TRP) to BCAA suggesting that TRP availability for brain serotonin (5-HT) synthesis would also be decreased. This could be an undesirable effect if BCAA mixtures were to be used in the treatment of patients with mood disorders because of the risk of precipitating depressive episodes (Smith et al. 1997). The present study employed a TRP supplemented BCAA drink with the aim of limiting the decrease in TRP availability seen with the BCAA mixture alone. We also compared the effect of the two mixtures on plasma PRL to test the hypothesis that the increase in plasma PRL produced by BCAA would be greater in the absence of compromised 5-HT function.We studied 12 healthy subjects, seven men and five women (mean age 31 years, range 19-53 years). Subjects had no past history of mood disorder and had been drug free for the last month, and were decided to be free of current medical and axis 1 psychiatric disorder on the basis of a full medical and psychiatric examination, including the Structured Clinical Interview for DSM-IV. All subjects gave written informed consent to the study, which was approved by the local ethics committee. Each subject was tested on two occasions, 1 week apart in a double blind randomised crossover design On each test day, the subject was given a drink containing either 60 g BCAA, (valine 18 g, isoleucine 18 g and leucine 24 g) or 60 g BCAA with an added 2 g TRP.Plasma concentrations of leucine, isoleucine, valine, PHE, TYR, and TRP were measured at baseline ("0" min) and at 30-min intervals up to 300 min following ingestion, by an automated HPLC system which used fluorescent end-point detection and pre-column sample derivatisation (Furst et al. 1990). PRL levels were determined using a standard immunoradiometric assay (Netria, London, UK). Amino acid data were analysed with a two-way repeated measures analysis of variance (ANOVA) with "mixture" (BCAA alone versus BCAA with TRP) and "time" (baseline versus 300 min) as within-subject factors. Differences between the two mixtures were detected as significant mixture by time interactions on the ANOVA. PRL levels were similarly analysed, except that baseline PRL levels were taken from the nadir of plasma PRL levels which occurred at +90 min after mixture ingestion (data not shown). PRL responses were also calculated as area under the curve (AUC) by the trapezoid method with extrapolation of the baseline nadir from +90 min.As noted previously, the BCAA mixture produced a substantial decline in the ratio of TYR+PHE:BCAA and TRP:BCAA (Table 1). TRP sup...