Phospholipid preparations for the improvement of sleep

A method for one or both of improving sleep in a subject and treating at least one sleep problem in a subject, the method comprising administering a preparation comprising an effective amount of long chain poly unsaturated fatty acids (LC-PUFA) attached to phosphatidylserine (PS);

• wherein
• the weight percentage of the PS with respect to the preparation is greater than about 8%,
• the content of LC-PUFA attached to the PS in the preparation out of the total fatty acids content attached to the PS in the preparation is greater than about 10%,
• the content of EPA attached to the PS in the preparation out of the total fatty acids content attached to the PS in the preparation is greater than about 5%,
• the content of Palmitic acid attached to the PS in the preparation out of the total fatty acids content attached to the PS in the preparation is greater than 14% and lower than 42%,
• the content of Docosahexaenoic acid (DHA) attached to the PS in the preparation out of the total fatty acids content attached to the PS in the preparation is greater than about 6% and lower than about 25%,
• the content of Oleic acid attached to the PS in the preparation out of the total fatty acids content attached to the PS in the preparation is greater than 1% and lower than 15%, and
• the content of Linoleic acid attached to the PS in the preparation out of the total fatty acids content attached to the PS in the preparation is greater than about 0.1% and lower than about 6%;
• wherein the sleep problem comprises insufficient REM sleep;
• and
• wherein improving sleep comprises improving REM sleep.