This observational study aimed to evaluate the prevalence of suicidality in adult patients with ADHD using a dimensional approach and a validated instrument; we also analyzed socio-demographic and clinical factors potentially related to occurrence of SI or SB in these patients.
The Columbia-Suicide Severity Rating Scale (C-SSRS) has allowed us to better define and quantify a complex phenomenon such as suicidality, which can’t be resumed in a single question. As highlighted by Posner and colleagues in the original validation results of this scale, a generic wish to be dead does not present a comparable risk factor to SB when compared to active suicidal ideation. [4]. Furthermore, considering the high levels of impulsiveness in ADHD patients and the resulting risk of acting-out, identify those with active SI could play an important role in preventing suicide.
We identified a high prevalence of suicidality in adult patients with ADHD. Specifically, 59,5% of our sample reported wishing to be dead at least once in their life; moreover, 9,5% of the participants reported at least one lifetime SB. A considerable proportion of individuals with ADHD can be considered at high risk for suicide: 16,2% of our sample scored ≥ 4 on the severity scale of the C-SSRS, presenting lifetime active SI with a specific plan and intent (6,8%) or active SI with some intent to act but no plan (9,4%). Concerning SB, only a minority of our patients had actually attempted suicide (6,8%); many others, however, engaged in some SB, such as interrupted attempts (1,4%), aborted or self-interrupted attempts (2,7%), or in preparatory acts or behaviors (5,4%). Moreover, a considerable part of our sample (10,8%) engaged in NSSIB. Our results are reasonably in line with findings from a recent meta-analysis which evidenced a lifetime SI and SB prevalences of 40% and 18,9%, respectively [20].
The identification of a high suicidality risk among adults with ADHD underscores the necessity for focused assessment and careful monitoring within clinical practice. Regular clinical assessments and implementation of psychoeducational interventions, not only for patients but also for their familial and caregiving networks, can be crucial tools in addressing this complex clinical concern.
The severity of inattentive symptoms in adulthood appeared significantly associated with lifetime SI, while the severity of hyperactivity/impulsivity symptoms didn’t result to have an impact on suicidality (both SI, SSI, SB and NSSIB). This evidence suggests that the association between ADHD and suicidality could be mediated by inattention, which represents the core symptom of ADHD.
In accordance with this hypothesis, the only type of impulsiveness (measured through BIS-11) which resulted associated with suicidality (specifically with SSI) in our sample was attentional impulsiveness. This has been defined as an inability to focus attention or concentrate, and it assesses task-focus, intrusive thoughts, and racing thoughts. Instead, motor impulsiveness (acting without thinking) and non-planning impulsiveness (lack of futuring or forethought) didn’t result to affect both SI and SB, confirming that the risk of suicide in ADHD patients could depend on inattention rather than impulsivity itself.
Furthermore, while lifetime SI appeared related to the severity of inattentive symptoms in adulthood, we found that lifetime SSI was associated with the severity of inattentive symptoms during childhood. This result endorses the potential impact in adulthood of the symptoms during childhood, suggesting they may be prognostic factors. Prior research findings highlighted some predictive factors for suicidality in ADHD such early externalizing behaviors, adverse child experiences and negative father–daughter interactions, without focusing on inattentive symptomatology [31]. Therefore, considering SSI as the proper risk factor for suicide, exploring symptoms of attention deficit in childhood should be a target in ADHD patients. However, in clinical practice, identifying this cluster in childhood can be challenging due to the occasional unavailability of caregivers and the less overt presentation of inattention, which is not always the predominant feature of ADHD, particularly in children.
It is important to underline that in our sample SI, SSI, SB and NSSIB didn’t appear associated with any psychiatric comorbidity, in line with prior research findings from Septier’s meta-analysis [20].
Furthermore, we did not find any clinical or socio-demographic factors significantly associated with SB and NSSIB in adult patients with ADHD, indicating a direct correlation between these phenomena.
Unlike SB and NSSIB, other clinical factors were found to be associated with SI and SSI in addition to the previously mentioned inattentive symptoms and attentional impulsiveness. Patients with SI exhibited significantly more frequent impairments in social functioning, though not in other areas. This finding, consistent with existing literature, supports the notion of a causal link between social isolation and suicide, as well as the protective influence of social support against suicide [32]. Physical activity appeared to be associated with a lower lifetime prevalence of SSI, suggesting that being physically active could reduce suicidal risk. This evidence, in line with a recent meta-analysis ran on psychiatric patients [33], is relevant given that there are only few interventions which proved to be effective against suicide and they aren’t always available in public health system.
Low self-esteem is a known risk factor for suicide, especially in emerging adulthood [34]. It appeared significantly related with lifetime SI (it was found in 84,1% of the patients with suicidality history), but it is important to underline how frequently it occurs also in patients without an history of suicidality (60%), being one of the most associated symptoms in ADHD.
No gender differences arised regarding both SI, SSI, SB and NSSIB in our sample.
Our study has several strengths, including a well characterized clinical sample, the use of standardized validated assessments and a dimensional approach. However, our study should be considered in light of some limitations. First, the cross-sectional design does not allow causal relationships to be inferred or etiological factors to be assessed. Moreover, the sample did not include completed suicides, meaning that we are unable to test whether the results are generalizable to suicide deaths. Another study limitation is represented by the small number of participants: thus, the results about potential predictors of SB/NSSIB should be considered as preliminary.
Despite these limitations, our findings are noteworthy since they highlight that a significant proportion of patients with ADHD have lifetime SI/SB. Moreover, this association appeared not to be affected by psychiatric comorbidities. Instead, our findings suggest that the risk of suicide in ADHD patients could depend on inattention itself.
In conclusion, adult patients with ADHD are to be considered at risk of suicide and it is important to determine which patients should be considered at higher risk, in order to guide preventive pharmacological or psychological treatments and psychoeducational interventions. Therefore, for adult ADHD patients, alongside pharmacological therapy, the utilization of psychotherapeutic interventions, particularly cognitive-behavioral and psychoeducational approaches, is crucial. These interventions aid patients in gaining a deeper understanding of their condition, enhancing self-esteem, and guiding them towards adopting healthy and protective lifestyles, such as regular physical activity.