A chronobiological approach to addiction

Recent chronobiological studies show that drug consumption has a negative effect on circadian rhythmic expression. Circadian rhythm may even disappear in extreme cases, which suggests a lesser quality of the wake and sleep periods. Moreover, some circadian genes (Clock, Period) may be involved as biological risk factors in drug addictions. At the same time, the modification of their genetic expression has been found in patients with addiction disorders. Evening circadian typology is currently being considered as a risk factor in the onset and maintenance of drug consumption, while the morning typology appears to be a protection factor. The circadian genes are also related to psychopathologies such as mood disorders, and in the future, their implication in dual pathology should be further studied. Preventive and therapeutic approaches to addiction should take into account circadian rhythmic organization. In many cases, it may suffice to establish regular time patterns of wake-sleep, meals and daily activity with a tendency towards a morningness pattern of functioning. Other strategies, such as light therapy and melatonin administration, may be applied for long periods of time, since they have shown an excellent degree of security, and may also be a protective measure against relapse or the appearance of neuropsychiatric symptoms.