Barbara Loessl

Sleep restriction over several days does not affect long-term recall of declarative and procedural memories in adolescents

OBJECTIVES There is broad evidence that sleep as opposed to waking facilitates the consolidation of both declarative and procedural memory. The current study addressed the question whether different extents of sleep restriction after learning would impair long-term memory consolidation in adolescents. METHODS Eighty-eight healthy adolescents were randomized to five different sleep protocols with 9, 8, 7, 6 or 5 h of time in bed for four consecutive nights under controlled conditions that excluded daytime sleep. Declarative (word-pair task) and procedural memory (mirror tracing task) encoding was assessed prior to the sleep restriction protocol. Recall was assessed after two recovery nights following the sleep protocol and 4 weeks later. RESULTS Sleep diaries and actigraphy data demonstrated that the participants closely followed the sleep protocols. There were no differences in demographic parameters or memory encoding at baseline. In contrast to the initial prediction, restriction of nocturnal sleep over four consecutive nights had no significant impact on declarative or procedural memory consolidation. Polysomnographic monitoring after sleep restriction demonstrated a high preservation of the amount of slow wave sleep in the restricted conditions. CONCLUSIONS The results suggest that adolescents show a high resilience of memory consolidation to substantial sleep curtailment across four nights that might be promoted by increased sleep intensity under conditions of sleep restriction.

No persisting effect of partial sleep curtailment on cognitive performance and declarative memory recall in adolescents

Growing evidence indicates that sleep facilitates learning and memory processing. Sleep curtailment is increasingly common in adolescents. The aim of this study was to examine the effects of short‐term sleep curtailment on declarative memory consolidation in adolescents. A randomized, cross‐over study design was chosen. Twenty‐two healthy subjects, aged 14–16 years, spent three consecutive nights in the sleep laboratory with a bedtime of 9 h during the first night (adaptation), 4 h during the second (partial sleep curtailment) and 9 h during the third night (recovery). The control condition consisted of three consecutive nights with bedtimes of 9 h. Both experimental conditions were separated by at least 3 weeks. The acquisition phase for the declarative tests was between 16:00 and 18:00 hours before the second night. Memory performance was examined in the morning after the recovery night. Executive function, attention and concentration were also assessed to control for any possible effects of tiredness. During the 4‐h night, we observed a curtailment of 50% of non‐rapid eye movement (non‐REM), 5% of slow wave sleep (SWS) and 70% of REM sleep compared with the control night. Partial sleep curtailment of one night did not influence declarative memory retrieval significantly. Recall in the paired‐associate word list task was correlated positively with percentage of non‐REM sleep in the recovery night. Declarative memory consolidation does not appear to be influenced by short‐term sleep curtailment in adolescents. This may be explained by the high ability of adolescents to compensate for acute sleep loss. The correlation between non‐REM sleep and declarative memory performance supports earlier findings.

The impact of increasing sleep restriction on cortisol and daytime sleepiness in adolescents

Sleep restriction is a widespread phenomenon, specifically in adolescents. This study investigated the impact of increasing sleep restriction in adolescents on cortisol levels and daytime sleepiness. Eighty-eight healthy adolescents were randomized to five sleep restriction protocols (four consecutive nights with 9, 8, 7, 6, or 5 h time in bed). Polysomnography (baseline and last experimental night) and multiple sleep latency test (day 6) data were obtained. Saliva cortisol levels were assessed half-hourly in the evening before and in the morning after the baseline and the last experimental night. Four nights of sleep restriction in healthy adolescents lead to a linear increase of objective sleepiness, but had no significant effect on evening or morning cortisol levels. The lack of detrimental effects of sleep restriction on cortisol levels might be due to compensation mechanisms during sleep.

Psychometric properties of the German version of the Motivational Interviewing Treatment Integrity Code

Motivational interviewing (MI) is effective in the treatment of addictions. To evaluate MI adherence of therapists, the Motivational Interviewing Treatment Integrity Code (MITI) was developed. MI is used in German-speaking countries, but there is no equivalent to the MITI. Our aim was to adapt the MITI for use in German language settings (MITI-d). Twenty-eight session tapes of Alcoholism Specific Psychotherapy utilizing MI were rated by two student raters and the MITI-d instructor. To evaluate interrater reliability, intraclass correlation coefficients (ICCs) were computed. ICCs were good to excellent for relevant MI constructs, except for Complex Reflections, MI-nonadherent Behaviors, Empathy, and MI Spirit. The evaluation of test-retest reliability for the student raters showed good to excellent results. The MITI-d is a psychometrically sound instrument for evaluating basic MI competence in German language settings.

The Efficacy of Stepped Care Models Involving Psychosocial Treatment of Alcohol Use Disorders and Nicotine Dependence: A Systematic Review of the Literature

Of particular interest in the psychosocial treatment of addictions is determining how much therapy is required to bring about behaviour change. Stepped care approaches, where non-responders to a less intensive therapy receive a more intensive intervention, aim to only provide intensive assistance to those who need it, thereby allocating therapeutic resources more efficiently. This paper provides a systematic review of stepped care models involving different levels of psychosocial intervention for the treatment of alcohol use disorders and smoking cessation. Five publications on alcohol and three on smoking were included in the review. Due to the heterogeneity of outcome measures, participant characteristics and interventions, a narrative review format was employed. Overall, little evidence was found to suggest that stepping up non-responders to more intensive therapy improved outcomes, a finding that could partially be attributed to a lack of power to find significant effects. In one study, the application of a stepped care approach was found to reduce treatment costs compared with usual care. There was some evidence that the greater differentiation between the intensity of the interventions offered at each step, the better the outcome. Further research is needed to evaluate the efficacy of stepped care approaches to providing psychosocial treatment, employing larger samples and/or consistent definitions of the nature of the interventions offered at each step, and assessing treatment response in a timely manner.

What Works for Patients in Outpatient Treatment for Alcohol Addiction? An Explorative Study into Clients' Evaluation of Subjective Factors and Therapy Satisfaction

This explorative survey investigated clients’ evaluation of therapy elements and other supportive factors within a randomized controlled trial. The treatment of patients with alcohol dependence consisted of pharmacotherapy (acamprosate/naltrexone/placebo) and biweekly medical management (MM). Forty-nine study participants were surveyed with a questionnaire to measure both the patients’ satisfaction with the therapy and the subjective assessment of treatment elements and supportive factors. Study participants were highly satisfied with the treatment. The supportive factors previously identified by Orford et al 1 were confirmed. ‘Pharmacotherapy’ was rated significantly less effective than ‘MM’ and ‘global study attendance’ (P < 0.001). The significant differences in the evaluation of treatment elements point to a preference for regular low-key contacts rather than for medication. Such contacts based on MM could be a useful intervention in clinical care, and its effectivity should be examined more closely in further research.