Classical conditioning for preserving the effects of short melatonin treatment in children with delayed sleep: a pilot study

Abstract

Melatonin treatment is effective in treating sleep onset problems in children with delayed melatonin onset, but effects usually disappear when treatment is discontinued. In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention deficit hyperactivity disorder (ADHD) or autism. After a baseline week, 16 children (mean age: 9.92 years, 31% ADHD/autism) received melatonin treatment for 3 weeks and then gradually discontinued the treatment. Classical conditioning was applied by having children drink organic lemonade while taking melatonin and by using a dim red light lamp that was turned on when children went to bed. Results were compared with a group of 41 children (mean age: 9.43 years, 34% ADHD/autism) who received melatonin without classical conditioning. Melatonin treatment was effective in advancing dim light melatonin onset and reducing sleep onset problems, and positive effects were found on health and behavior problems. After stopping melatonin, sleep returned to baseline levels. We found that for children without comorbidity in the experimental group, sleep latency and sleep start delayed less in the stop week, which suggests an effect of classical conditioning. However, classical conditioning seems counterproductive in children with ADHD or autism. Further research is needed to establish these results and to examine other ways to preserve melatonin treatment effects, for example, by applying morning light.

Keywords: children; classical conditioning; delayed sleep; melatonin.

Figure 1

Study design. Notes: T0 represents baseline; T1 represents end of treatment; T2 represents end of stop week.

Figure 2

Classical conditioning procedure. Notes: Conditioned stimuli were a biological lemonade with peppermint taste and a dim red light lamp with curly cord. Children were instructed to drink the lemonade (CS) at the moment that they took the melatonin tablet (US) to couple the lemonade to the rise in melatonin secretion (UR) and making the lemonade a CS for melatonin secretion (CR). The red light (CS) was turned on when the child went to bed and felt sleepy (US) to couple the red light to falling asleep (UR) and making it a CS for falling asleep (CR). Parents were instructed to switch the red light off when the child got up in the morning. Abbreviations: CS, conditioned stimulus; US, unconditioned stimulus; UR, unconditioned response; CR, conditioned response.

Figure 3

Average sleep scores in different treatment phases by group and ADHD/autism diagnosis. Notes: A Sleep onset latency (sleep diary); B sleep start (sleep diary); C sleep onset latency (actigraphy); D sleep start (actigraphy); E total sleep time (actigraphy); F sleep efficiency (actigraphy). Abbreviation: ADHD, attention deficit hyperactivity disorder.