Paper 2 - Abnormal Psychology - Biological Treatments of MDD (antidepressants)

Assumption of biological approaches to treatment

Biological approaches to treatment are based on the assumption that if the problem is based on biological malfunctioning, drugs should be used to restore the biological system.

For example, since MDD is assumed to involve a neurotransmitter imbalance, antidepressant medications are used to restore an appropriate chemical balance in the brain.

These medications modify the levels of neurotransmitters available in the synaptic clefts.

Goal of treatment for MDD with antidepressant medication

To provide symptom relief

Positive response to drug treatment

Clear improvement in symptoms.

Remission

Near absence of symptoms

Relapse

When symptoms return after the medication is discontinued.

How do drugs work

Through affecting neurotransmitters (e.g. dopamine, serotonin, or noradrenaline).

e.g. serotonin plays a key role in mood regulation, so specific drugs can target the level of serotonin.

Aim of antidepressants

To inc/dec the levels of available neurotransmitters in the synaptic clefts.

- Neurotransmission is affected by reuptake pumps.

- After the neurotransmitter is released and binds to the receptor site on the post-synaptic membrane, the neurotransmitter is reabsorbed into the terminal buttons.

Selective Serotonin Reuptake Inhibitors (SSRIs)

Block this process of reuptake and thus allow there to be higher levels of serotonin in the synapse, prolonging their mood boosting effects.

Tricyclic Antidepressants (TCAs)

Inhibit the reuptake of neurotransmitters like norepinephrine and serotonin, ensuring they remain in the synaptic cleft for longer to amplify their mood enhancing effects.

Monoamine Oxidase Inhibitors (MAOIs)

Inhibit monoaminoxidase (enzyme that breaks down neurotransmitters). This leads to an inc. availability of neurotransmitters like serotonin and norepinephrine, essential in mood regulation.

Elkin et al (1989) aim

To see if there was any significant difference in the effectiveness of the 3 approaches to therapy (CBT, IPT, and drug therapy).

Elkin method

Sample of 250 depressed patients coming from 3 diff treatment centers in Pittsburgh, Washington DC, and Oklahoma City.

Depressed clients were randomly assigned to one of four treatment conditions for 4 months: IPT, CBT, the drug imipramine, or a placebo pill.

The imipramine and placebo conditions were paired w/ clinical management in which minimal supportive therapy was provided because of the ethical need to provide some therapy for clients in those conditions.

Patients had to meet the diagnosis of MDD w/ symptoms present at least in the 2 weeks previous to the study and were excluded if they had any other disorders.

After obtaining informed consent, ppts were randomly assigned to treatment conditions at each site. A total of 28 therapists took part - 8 in CBT, 10 in IPT, 10 in drug therapy. All treatments lasted 16 weeks.

CBT patients received 12 sessions during the first 8 weeks, followed by weekly sessions during the second half of the study.

Patients were carefully monitored. A large number of assessments were carried out before, during, and after. In general, 3 areas were assessed: symptoms, life functioning, and functioning related to the treatment.

The assessments acquired info from the client, a clinician blind to the treatment condition, and a significant other.

Elkin results

There was no significant difference in the reduction of MDD or improvement of functioning btwn CBT and IPT or between either of them and imipramine plus clinical management.

The 3 treatments achieved significant and equivalent degrees of success and were superior to the placebo condition.

Imipramine was faster than the other treatments in reducing depressive symptoms during treatment. By the end of the 16 weeks of therapy, the 2 psychotherapies had caught up w/ the drug.

At the 18 month follow up, only 20-30% of the ppts remained completely symptom free of depression, regardless of the treatment received.

Patients in both IPT and CBT reported significantly greater effects of treatment.

Elkin conclusion

While all treatments (CBT, IPT and medication) were effective in reducing depressive symptoms, no single approach was superior. The results emphasize the importance of matching treatment to individual patient needs and the need for a holistic approach to treatment.

This finding highlights that while biological treatments like antidepressants can be effective, their success may improve when combined with therapies addressing psychological factors, such as CBT and IPT. Integrating biological and psychological treatments allows for a more comprehensive approach, targeting both the neurological and behavioral aspects of depression.

Elkin evaluation

- The Elkin study is criticized for inconsistencies and high drop out rates. Jacobson and Hollon (1996) found that treatment outcomes varied across sites. For example, CBT and IPT were as effective as imipramine at different sites. Additionally, 33% of imipramine patients dropped out before completing treatment, unlike in other groups. These inconsistencies and high attrition rates raise concerns about the generalizability of the results and the tolerability of imipramine, which could have biased findings. This highlights the need for further research to confirm the study's conclusions.

+ The study's use of data triangulation strengthens its findings. The effectiveness was assessed using info from the patient, therapist, and an objective observer, reducing potential bias. This approach minimizes the risk of demand characteristics from the patient, or observer bias from the therapist, providing a more reliable evaluation of treatment effectiveness. Therefore, the use of multiple data sources enhances the validity of the study's conclusions.

Cipriani et al (2018) aim

to investigate the extent to which antidepressants are effective (in comparison to placebos)

Cipriani method

Conducted a meta analysis.

This systematic review included placebo-controlled and head-to-head (placebo Vs SSRI) trials of 21 antidepressants used for the acute treatment of adults (≥18 years old and of both sexes) with MDD diagnosed according to standard operationalized criteria.

(The study excluded quasi-randomized trials and trials that were incomplete or included 20% or more of participants with bipolar disorder, psychotic depression, or treatment-resistant depression; or patients with a serious concomitant medical illness).

522 trials were reviewed, consisting of a total of 116,477 participants.

Cipriani results

In terms of efficacy, all antidepressants were more effective than placebo.

Of the active antidepressant drugs, fluoxetine was found to be least effective, BUT was better tolerated (signified by lower drop out rates, and less reporting of side effects).

Amitriptyline was the most effective, but 6th best tolerated.

Cipriani conclusion

All antidepressants were more efficacious than placebo in adults with major depressive disorder.

Smaller differences between active drugs were found when placebo-controlled trials were included in the analysis, whereas there was more variability in efficacy and acceptability in head-to-head trials.

Cipriani evaluation

+ Controlled for external variables, such as co-morbidity, which strengthens the findings. The study excluded participants with co-morbid conditions, isolating the effects of antidepressants on depression alone. Controlling for co-morbidity reduces confounding effects, ensuring that the results more accurately reflect the medication's impact on depression. This control over extraneous variables enhances the study's validity and supports its conclusions.

- Focus on effectiveness does not address the root causes of depression. Cipriani et al. demonstrate the efficacy of antidepressants but do not explore underlying biological or psychological causes. Without addressing the cause, treatment may only alleviate symptoms temporarily, potentially resulting in relapse. This suggests that while antidepressants can be effective, they may need to be part of a more comprehensive approach to depression.

Limitation of antidepressants

- The risk of dependency and high relapse rates after discontinuation. Antidepressants can lead to "discontinuation syndrome," or withdrawal symptoms, when stopped. Research by Hollon et al. (2005) found that 76% of patients relapsed after discontinuing antidepressants following a 16-week treatment period, compared to only 31% of those who had received Cognitive Behavioral Therapy (CBT). These findings suggest that while medication can provide short-term relief, it may not address the underlying causes of depression, leading to a cycle of dependency and relapse. In contrast, CBT appears to have a more lasting impact, reducing the risk of relapse after treatment ends. This indicates that while drug treatments can be effective for symptom management, psychological therapies may offer a more sustainable, long-term approach to preventing relapse in depression treatment.

Strength of antidepressants

+ its effective in alleviating severe symptoms, allowing individuals to manage daily life more easily. Geddes et al. (2003) conducted a systematic review of 31 randomized trials involving 4,410 patients and found that antidepressants effectively treated depression and reduced relapse rates. Additionally, antidepressants have contributed to a decrease in hospitalizations for psychological disorders. By managing symptoms effectively, antidepressants can prevent severe mood episodes and potentially reduce the risk of suicide, providing support for individuals with severe depression. Therefore, antidepressants are a valuable treatment option.