Pilot study of a ketogenic diet in bipolar disorder

BACKGROUND

Recent evidence from case reports suggests that a ketogenic diet may be effective for bipolar disorder. However, no clinical trials have been conducted to date.

AIMS

To assess the recruitment and feasibility of a ketogenic diet intervention in bipolar disorder.

METHOD

Euthymic individuals with bipolar disorder were recruited to a 6-8 week trial of a modified ketogenic diet, and a range of clinical, economic and functional outcome measures were assessed. Study registration number: ISRCTN61613198.

RESULTS

Of 27 recruited participants, 26 commenced and 20 completed the modified ketogenic diet for 6-8 weeks. The outcomes data-set was 95% complete for daily ketone measures, 95% complete for daily glucose measures and 95% complete for daily ecological momentary assessment of symptoms during the intervention period. Mean daily blood ketone readings were 1.3 mmol/L (s.d. = 0.77, median = 1.1) during the intervention period, and 91% of all readings indicated ketosis, suggesting a high degree of adherence to the diet. Over 91% of daily blood glucose readings were within normal range, with 9% indicating mild hypoglycaemia. Eleven minor adverse events were recorded, including fatigue, constipation, drowsiness and hunger. One serious adverse event was reported (euglycemic ketoacidosis in a participant taking SGLT2-inhibitor medication).

CONCLUSIONS

The recruitment and retention of euthymic individuals with bipolar disorder to a 6-8 week ketogenic diet intervention was feasible, with high completion rates for outcome measures. The majority of participants reached and maintained ketosis, and adverse events were generally mild and modifiable. A future randomised controlled trial is now warranted.

Judgments of social appropriateness by children and adolescents with autism

Children and adolescents with autism (autism group, n = 19) and those without autism (Nonautism group, n = 19) of similar age and IQ were asked to make judgments of the social appropriateness of 24 videotaped, staged scenes with adult actors. Each scene depicted an appropriate or an inappropriate interaction. Half contained verbalizations, and half did not. After each scene, the participant was asked: (1) Was that o.k. or was something wrong with it? If the participant judged the scene was wrong, she or he was asked: (2) What was wrong with it?; and (3) Why was that wrong? Both groups correctly identified inappropriate behaviors most of the time, and correct behaviors almost all of the time. However, the Nonautism group detected inappropriate behaviors significantly more often than the Autism group, for verbal but not nonverbal scenes. It was also significantly easier for both groups to identify inappropriate behaviors in the nonverbal than in the verbal scenes. Ratings of the explanations given for Question 3 differed significantly between the groups for verbal but not for nonverbal scenes, with Nonautism participants more likely to give explanations involving social norms and principles, and the Autism group more likely to give explanations that were irrelevant or idiosyncratic.

Emotion recognition in autism: verbal and nonverbal information

This study examined the roles of verbal and nonverbal sources of information in the ability of persons with and without autism to recognize emotion. Child, adolescent, and young adult participants in four groups [Lower Functioning Autism (LFA) (n = 17), High Functioning Autism (HFA) (n = 18), Lower Functioning Comparison (LFC) (n = 18), and High Functioning Comparison (HFC) (n = 23)] identified emotions shown (happy, angry, sad, surprised, or neutral) in video clips of individuals expressing emotion verbally, nonverbally, or both. Verbal expressions of emotion were either Explicit, Implicit, or Neutral, whereas nonverbal expressions were Animate or Flat (3 x 2). Pairwise ANCOVAs indicated no group differences between HFA and HFC groups or between the LFA and LFC groups, and indicated instead group differences between higher and lower functioning persons. With groups collapsed into High Functioning (HF) and Lower Functioning (LF), significant group differences were found. Performance of LF individuals suggested they had difficulty inferring how a person felt based on what the person said, if the emotion was not explicitly named. Performance of HF individuals suggested they relied more on nonverbal than on verbal information to determine a speaker's emotion, except where the emotion was explicitly named. Results suggested that persons with autistic spectrum disorders can use affective information from multiple sources in much the same ways as persons of comparable developmental level without autism.

Biphasic indentation of articular cartilage--II. A numerical algorithm and an experimental study

Part I (Mak et al., 1987, J. Biomechanics 20, 703-714) presented the theoretical solutions for the biphasic indentation of articular cartilage under creep and stress-relaxation conditions. In this study, using the creep solution, we developed an efficient numerical algorithm to compute all three material coefficients of cartilage in situ on the joint surface from the indentation creep experiment. With this method we determined the average values of the aggregate modulus. Poisson's ratio and permeability for young bovine femoral condylar cartilage in situ to be HA = 0.90 MPa, vs = 0.39 and k = 0.44 x 10(-15) m4/Ns respectively, and those for patellar groove cartilage to be HA = 0.47 MPa, vs = 0.24, k = 1.42 x 10(-15) m4/Ns. One surprising finding from this study is that the in situ Poisson's ratio of cartilage (0.13-0.45) may be much less than those determined from measurements performed on excised osteochondral plugs (0.40-0.49) reported in the literature. We also found the permeability of patellar groove cartilage to be several times higher than femoral condyle cartilage. These findings may have important implications on understanding the functional behavior of cartilage in situ and on methods used to determine the elastic moduli of cartilage using the indentation experiments.