Which effect is NOT typically associated with stimulant withdrawal?

Stimulant withdrawal is characterized by a range of symptoms that often reflect a rebound effect from the body's adjustment to the absence of the stimulant. Common effects of stimulant withdrawal typically include irritability, apathy, and fatigue, as the body begins to rebound from the heightened levels of arousal and energy that stimulants can produce.

Irritability arises because the individual may experience heightened sensitivity and mood disturbances when the stimulant is no longer present. Apathy can occur due to a lack of motivation and energy, contrasting with the stimulating effects that the substance had while being used. Fatigue is also a prominent symptom, as it represents the body's depletion of energy resources after prolonged stimulant use.

Increased heart rate, on the other hand, is usually a physiological response associated with the effects of stimulants while they are active in the system, as they elevate adrenaline levels and stimulate the central nervous system. When withdrawal occurs, the body typically does not exhibit an increased heart rate; instead, heart rate may decrease as the system adjusts back to a baseline level of function without the stimulant's influence. This distinction makes increased heart rate the correct answer to the question regarding which effect is not typically associated with stimulant withdrawal.