Drug Addiction Lecture Continued (2/3)

Introduction to the topic of drug use and addiction in the context of psychological theory.
Discusses the importance of following along with the material from the reading and slides.

Drugs are often taken initially for pleasure due to the effects they produce.
- This pleasure-driven use may shift to usage aimed at avoiding withdrawal symptoms once addiction occurs.

The opponent process theory is central to understanding changes in body response and addiction mechanics.
- Repeated exposure to drugs modifies the body's response (referred to as the d process), which becomes larger, stronger, faster, and longer lasting.
- The relationship between the a process (the initial pleasure) and the b process (the withdrawal experience) is crucial.
- As the a state (good feelings/effects from drugs) diminishes, the b state (negative withdrawal effects) becomes prolonged and intensified.
- Implication of the theory: As drug use continues, even minimal drug exposure can trigger the strengthened b process, leading to cravings.

The body's adaptation can make the experience of drug effects less distinct, creating a blurry line in perception.
- The extended b state induces a desire to escape withdrawal and return to drug use.

Repeated drug use often leads to decreased perception of drug effects due to:
- Tolerance: Repeated use results in a downregulation of dopamine receptors (the basal amygdaloid system), producing less pronounced effects from the drug.
- The specifics of tolerance can manifest as fewer receptors, lower neurotransmitter release, or varying efficacy of receptor action.
  - Mechanisms of tolerance are associated with the hypothalamic-pituitary-adrenal (HPA) axis and stress responses.
  - CRF (Corticotropin-Releasing Factor): An increase in this is observed during stress responses in the body, impacting dopamine levels.

When drug use ceases, there is an overall reduction in dopamine levels, leading to withdrawal symptoms which contribute to cravings.
- The decline in rewarding feelings (due to reduced dopamine) leads to a predominance of negative feelings as a result of the extended b state.

Over time, the good effects of drugs diminish while the bad effects increase, raising the question of why individuals continue to use them despite the negative consequences.
- Addresses the possible reasoning behind increased dosage as a response to tolerance, rather than a straightforward explanation of the motivation for continued use.
- The relationship between addiction and daily stress levels is explored, emphasizing the self-medication aspect where individuals may use drugs as a coping mechanism.

Withdrawal symptoms may not be as compelling as one might think for motivation to use drugs, as various factors interact:
- Manipulation of the body’s response can neutralize withdrawal or amplify pleasurable effects, allowing for varied responses to drugs based on learned behavior.
- In studies with animals, experiments show that conditioned responses can affect drug-seeking behavior where environmental cues trigger cravings or tolerance.
- Predictive cues related to drugs (e.g., seeing drug paraphernalia) can activate conditioned responses related to drug use.

Opponent Process Theory: A psychological model explaining the dual processes of pleasure and withdrawal during drug use.
D Process: The body's increased tolerance and response to the drug.
A Process: The initial pleasurable effects felt during drug intake.
HPA Axis: A complex set of interactions between the hypothalamus, pituitary gland, and adrenal glands that controls stress responses and affects drug-related behavior.
CRF: The neuropeptide released during stress, play a role in addiction-related stress responses.
Conditioned Tolerance: A learned response where stimuli predicting drug use can trigger withdrawal or reduce drug effects, even in the absence of the drug itself.