IOM report (2001) and by Goodwin and Jamison (1990), the reasons for non-adherence can range from failure to understand the regimen or to appreciate the consequences of not following it, to adverse side effects. Lithium, for example, can cause cognitive impairment, weight gain, tremor, thirst, or lethargy (Goodwin and Jamison, 1990). It may also be that those who do not maintain their medication regimen had been reaping no benefit from it. This in turn is related to two possibilities. First, the individual may not have been on the medication for a long enough period of time to experience symptom relief; most psychiatric medications exert the desired beneficial effects only after taking them for multiple weeks. Meanwhile, unpleasant side-effects often occur during this initial period. Second, there are some people for whom the medications do not bring significant symptom relief; these “treatment resistant” individuals range upwards of 25 percent of those treated for some disorders. However, true non-response to medication is difficult to study because of the high incidence of non-adherence to dosing regimes for psychiatric drugs.
Non-adherence to treatment is a critical issue in suicide prevention since a large percentage of those taking psychiatric medications who complete suicide have been shown to have insufficient blood levels of the drugs to have reaped any benefits. Adherence to psychiatric treatment is lower than for treatment of somatic disorders, likely due to the societal stigma and unpleasant drug side effects, which typically start before the therapeutic benefit. In addition, for bipolar disorder and schizophrenia, suicide is most likely during the first years after diagnosis, often before consistent drug and therapy treatments have been established. These two disorders are most frequently diagnosed in early adulthood, a period when people may not yet have the maturity and/or financial resources to overcome the high stigma, tolerate the unpleasant side effects, and mount the barriers to accessing treatment and establishing a successful treatment regimen.
Because of the high post-discharge suicide risk, many hospitals have implemented various forms of follow-up care for suicidal patients. Intensive follow-up, case management, telephone contacts, letters, or home visits sometimes improves treatment adherence (e.g., Termansen and Bywater, 1975; van Heeringen et al., 1995; Welu, 1977). Such interventions have produced mixed results with regard to suicidal behaviors: some have demonstrated decreased suicide attempts (Aoun, 1999; Termansen and Bywater, 1975; van Heeringen et al., 1995; Welu, 1977) and even completions (Motto and Bostrom, 2001), while others have found no effect on suicide attempts (Chowdhury et al., 1973; Litman and Wold, 1975).