Endorphins stimulate approach behaviour, but do not reduce subjective fear. A pilot study

The present study explored whether endorphins have a short-term influence on behavioural approach to a phobic object and on the experience of fear. In a double-blind design, spider phobics (n = 30) received a placebo, a low dose (25 mg) or a high dose (100 mg) of naltrexone, an endorphin blocker. Approach to a spider appeared to be negatively influenced by the endorphin blocker, but subjective fear was not significantly related to it. The findings support the view that endorphin release during anxiety stimulates courageous behaviour, but does not directly reduce the experience of fear.