Withdrawal is a major part of stimulant-related disorders. Those who have built a tolerance for the drugs and stop taking them are likely to feel unpleasant feelings, including anxiety, restlessness, and insomnia. Those withdrawing from methamphetamine or cocaine may experience additional headaches, emotional lability, and depressive feelings. Depending on the stimulant, the dose, and the duration of use, these depressive feelings can include suicidal ideation. In most cases, however, withdrawal from stimulants is not a medically dangerous endeavor.