Preventing recurrent depression

Nicola Klein’s PhD research into the gaps in our knowledge about preventing recurrent depression, under the supervision of Prof. Bockting and Dr Burger, was prompted by the high recurrence rate in people who had experienced depression. She examined both the clinical results and the cost-effectiveness of various interventions. Nicola Klein will be awarded a PhD by the University of Groningen on 21 March.

The main conclusions to be drawn from this research are that a combination of antidepressants and Preventive Cognitive Therapy (PCT) offers better protection from recurrence than antidepressants taken on their own. If people want to or have to stop using antidepressants, the results suggest that this should be done gradually with the help of PCT, despite the added costs that this incurs. It is important to monitor the process of stopping medication, which should be initiated during a stable period in the person’s life.

Instrument to estimate the risk

Almost 20 percent of adults in the Netherlands experience depression at some time in their life. Recurrent depression is common, but unlike with somatic conditions, there are no instruments to estimate the risk at the individual level. Under the supervision of Prof. Bockting and Dr Burger (UG/AMC), Klein has now developed a practical instrument to do just this. It is based on recognized predictors of recurrent depression, such as the number of previous depressive episodes and residual depressive symptoms. Klein: ‘Although the instrument was able to divide participants into meaningful risk categories, the overarching performance of the model is not good enough to implement the instrument in clinical practice.’

Beliefs

The research also focused on the link between people’s beliefs about the cause of depression and recovery, and the use of antidepressants. Klein: ‘Some people blame depression on biological factors, for example, while others believe that depression is caused by stressful life events. In addition, people believe very different things about what has helped them to recover. We wanted to see if we could find a link between these beliefs and adherence to medication, dosage and successfully coming off antidepressants. Contrary to the current literature, which claims that specific beliefs play a role in the use of antidepressants, we were unable to demonstrate any such link. We need more research into factors that can predict antidepressant use, including into stopping the use of medication and the matter of who is able to do this without a recurrence.’

Strategies

In recent decades, several strategies for effectively preventing recurrent depression have been developed. The research team examined the extent to which forms of therapy currently available (eight sessions of Preventive Cognitive Therapy or PCT) serve as an alternative to antidepressants, and whether a combination of PCT and antidepressants provides additional protection. Klein: ‘We monitored 289 people for two years. They had all experienced at least two bouts of depression and used antidepressants. They were randomly divided into three groups: one used PCT and antidepressants, one used antidepressants on their own and the last used PCT while coming off antidepressants. Combining PCT with antidepressants resulted in a 14% relative risk reduction of recurrent depression over 24 months, compared with the use of antidepressants on their own. The results for people who continued taking antidepressants were no better than those for people who were given PCT while coming off antidepressants.’

Internet therapy

Another part of the research involved studying the effect of Mobile Cognitive Therapy (PCT via the internet) with minimum therapeutic support on recurrent depression in people who had recovered from multiple bouts of depression, some of whom used antidepressants and some of whom didn’t. Klein concluded that MCT does not protect people from recurrent depression over a period of 24 months, and suggests that more therapeutic support could produce better results.

Cost-effectiveness

As the financial cost of depression is extremely high and policy staff need to be informed, Klein also looked into cost-effectiveness (the effects of specific interventions in relation to their cost). ‘The combination of antidepressants and PCT was not only clinically effective, but also cost effective compared with the use of antidepressants on their own,’ explains Klein. ‘Implementing this combination in the Dutch healthcare system would result in an estimated saving of € 95 million. Continuing with antidepressants on their own turned out to be more cost-effective than stopping the use of antidepressants while undergoing PCT. This method results in an estimated saving of € 83 million. The internet option, MCT, was neither clinically nor financially effective.’

More information

Contact: Nicola Klein